Sunday, 20 March 2016

Why do the planets circumvent the Sun?

Some visitors to the Teens Science Hall and Rauch Planetarium at the University of Louisville in Kentucky recently asked why the planets go around the sun. Most people take this fact for granted, but the answer involves many interesting and important concepts ideas. I will touch on a few.

First and foremost, saying the planets going around the sun is just another way of saying the planets in orbit around the sun. A planet orbiting the sun like the moon or the NASA satellite orbiting the Earth. Now what planet revolves around the sun, not the sun revolves around the earth? Lighter object orbiting a heavier one, the sun is, by far, the heaviest object in the solar system. The sun is 1,000 times heavier than the largest planet, Jupiter (who also happens to be my favorite planet), and it is more than 300,000 times heavier than the Earth (another planet I am very fond of). In the same way, the moon and satellites launch the Earth's rotation because it is so much lighter than our planet.



But now we still have the question of why anything is about something else. Complex reasons, but provided the first good explanation on the part of one of the greatest scientists ever, Isaac Newton, who lived in England about 300 years ago. And it was well known when he was alive, and being admired a lot of people to answer some of the most difficult and fascinating scientific questions of his day, but I'm sorry to say it has a long life in general was not happy. I wonder how he felt to know that even hundreds of years after his death, and is widely said to be one of the most brilliant scientists, is important, the product ever to have lived.

Newton realized that the reason why the planets revolve around the sun Why associated things fall to the ground and when we drop them. Attractiveness of the sun pulls on the planets, just as the Earth's gravity pulls down anything that is not held by some other powers, and keep you and me in the ground. Heavy objects (really, they are more massive) produces greater than lighter ones attractive, so a heavy weight in our solar system, the sun is practiced stronger attraction.

Now, if the sun is pulling the planets, why do not you just fall in and burn? Also, in addition to the fall toward the sun and the planets are moving sideways. This is the same as if you have a weight at the end of the series. If you swing around, you pull it down toward your hand, just as the gravity of the sun pulls the planet, but the movement and keep the side of the ball swinging around. Without lateral movement, it falls to the center; and without pulling toward the center, it will go flying off in a straight line, which is, of course, is exactly what happens if you leave the series.
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Thursday, 18 February 2016

Human Heart

Some Introduction of the Human Heart. The human heart is a hollow muscular organ, conical located between the two lungs above the diaphragm. Two thirds of the heart is to the left of the midline and 1/3 to the right.

In the heart, the corner points down and to the left. It is 5 inches (12 cm) long, 3.5 inches (8.9 cm) wide and 2.5 inches (6 cm) from front to back, and is about the size of a fist .. The heart comprises less 0.5 percent of total body weight.



Internal Layers of Heart

The heart has three layers. The smooth coating, inside the heart, made of epithelial tissues, called the endocardium. The middle layer of the heart muscle is called the myocardium, which is made of cardiac muscles and important part of the heart. It is surrounded by a full call pericardial sac, which is outside fluid.
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Earth

Some Information of the Earth Planet.

Planet info.


Mass: 5,972,190,000,000,000 billion kg
Equatorial Diameter: 12,756 km
Polar Diameter: 12,714 km
Equatorial Circumference: 40,030 km
Known Moons: 1
Notable Moons: The Moon
Orbit Distance: 149,598,262 km (1 AU)
Orbit Period: 365.26 Earth days
Surface Temperature: -88 to 58°C


About The Earth


Earth's rotation is gradually slowing

This statement is happening almost imperceptibly, in approximately 17 milliseconds per hundred years, but the rate at which it occurs is not perfectly uniform. This has the effect of lengthening our days, but it happens so slowly that it could be up to 140 million years before the last one day there will be increased to 25 hours.

Earth once believed to be the center of the universe

Because of the apparent motions of the Sun and planets in relation to their view, the ancient scientists insist that the Earth remained static, while other celestial bodies traveling in circular orbits around it. Over time, the view that the Sun was the center of the universe was postulated by Copernicus, although this is not the case.

Earth has a strong magnetic field

This phenomenon is caused by the nickel-iron core of the planet, along with its rapid rotation. This field protects Earth from the effects of solar wind.

There is only a natural satellite of planet Earth

As a percentage of the size of the body it orbits, the Moon is the largest of all the planets in our solar system satellite. In real terms, however, it is only the fifth largest natural satellite.

Earth is the only planet not named after a God

The other seven planets in our solar system are named after Roman gods and goddesses. Although only Mercury, Venus, Mars, Jupiter and Saturn were named in ancient times, because they were visible to the naked eye, the Roman method of naming planets remained after the discovery of Uranus and Neptune.

Of all the planets in our solar system, Earth has the highest density

This varies according to the part of the planet; For example, the metal core is denser than the crust. The average density of the Earth is about 5.52 grams per cubic centimeter.

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Velocity of Light



A fundamental constant representing the speed of electromagnetic radiation in a vacuum and is approximately equal to 2.9979 × 1010 centimeters per second is known as speed of light.

wave velocity of light in vacuum, c, is the same for all wavelengths of light, but the speed in a material medium is different for different wavelengths. the refractive index of a medium, or (Meu) 

u = c / v

where v is the speed of light in the medium. Since v change with the change in the wavelength, or also changes with wavelength.

Relationship between frequency, wavelength and speed.


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Diffraction

Diffraction describes the change in direction of a wave as it travels between or around obstacles. It is similar to the reflection and refraction that implies a change in the direction of the waves when they encounter a change of medium. Reflection describes how waves bounce off surfaces. Refraction describes how bending waves as they pass through the boundary between two different media.



Diffraction is different. In diffraction, waves actually bend around objects in its path or bend through openings in between two barriers. You may have seen the diffraction occurs when water waves travel through a hole in a wall or a pier. Waves are bent out of the wall opening and the fan outward from the gap. To see how diffraction really works, let's first take a look at the sound waves.

Diffraction of Sound


It is easy to imagine the sound waves bend around obstacles. Have you ever tried to talk to someone who is standing in an adjacent room? Even if that person is not in your line of sight, usually you can hear at a reasonable volume. This is because their sound waves bend around the edges of the walls and doors to traveling to that person. The same happens when that person talks back to you.

Diffraction of sound waves is one reason that animals can communicate over long distances. Think of the places most animals live. Forests, mountains, grasslands, swamps and all have plenty of features of vegetation and earth blocking visual communication. Animals can still be in contact with each other because their vocalizations get beyond that. Their sound waves bend around obstacles and travel to your target audience.

Effects of Wavelength


Some animals are better at long distance communication than others. Elephants, for example, can communicate through miles of land in order to keep their herds together while they are traveling. People have not always known about elephant communication, and vocalizing at such low frequencies that can not even hear it. Elephants using infrasound, or sound waves with frequencies below 20 Hz. These low frequency, long wavelength diffraction actually sounds around objects in a greater than other sounds, HF grade. In fact, the amount of bending that occurs in any wave depends on the wavelength of the wave.

Think for a minute about why this might be true. In order for a wave to bend around an obstacle, the wavelength of the wave should be greater than the obstacle. The same is true for waves traveling through an opening. The wavelength must be greater than if the aperture to pass through the opening and out the other side. For any obstacle or given aperture, the waves with wavelengths longer wavelengths lean over the waves with wavelengths shorter wavelengths. If the wavelength is less than the obstacle or opening, then diffraction occurs hardly at all.
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Scientific Reason Behind Hiccups



It's easier to say you do not remember the first hiccup, because it took place probably before you were born. It is customary for the development of the human embryo have hiccups in the womb, and yet even though we experience them throughout our lives, and the reason for this action is voluntary defied explanation.

To unravel the mystery of why we hiccup - that do not serve any useful purpose is clear - they are looking at our past evolutionary scientists for clues among distant relatives in the future. One promising candidate: amphibians, in certain frogs.

And it raised the mechanics of what happens during a storm this theory. It includes a whirlwind, known in medical circles as a hiccup, a sharp contraction in the muscles used for inhalation - the diaphragm, the muscles of the chest wall and neck and others. Prey for this, at the same time, by inhibiting the muscles used during exhalation.

Here, the back of the tongue and roof of the mouth is moving to the top, followed by the closure of the clamping of the vocal cords, also known as the glottis. This last part, and the closure of the glottis, is the source of the name of the sound, "the coalition." As you are undoubtedly of direct experience, and this process does not happen just once, but repeated rhythmic manner.

It seems that the tiny frogs that appear in a similar physiological behavior.

"Halfway through the tadpole development both lungs that breathe air and gills of the water to breathe," wrote William A.. Whitelaw, a professor at the University of Calgary, in Scientific American magazine. "To breathe water, it fills the mouth with water and then close the glottis and forces the water through the gills." This procedure is like a whirlwind in many primitive air breathers, such as gar, lungfish and other amphibians that have nostrils.

Recent evidence linking hiccups in humans, these creatures are originally electric trigger a storm in the brain, according to Neil Shubin, a professor of organic biology and anatomy at the University of Chicago. The Guardian newspaper: "convulsions in membranes we have, is run hiccups by electrical signals generated in the brain stem. Brain amphibians as relating stems emit similar signals, which control the normal movement of the nostrils. Stems our brain, it inherited from the ancestors of amphibians, still boom signals strange production hiccups that are according to Shubin, basically the same phenomenon in gill breathing. "

If hiccups are the remains of the genetic code passed down from the ancestors of amphibians have, it can be true that they perform any useful function in humans, despite the continuation of the last 370 million years ago for the first of our ancestors set foot on dry land?

Christian Strauss, a scientist at the Pitié-Saltpetriere Hospital in Paris, has developed the theory that hiccupping may be a mechanism to help learn the sucking mammals, which involves a series of similar movements. Allen said package, an expert in neuroscience at the University of Pennsylvania BBC while reasonable, and this theory can be difficult to prove.

Even Strauss and his colleagues can demonstrate a relationship between brain regions that control feeding, and those that lead to hiccups, the purpose of a mysterious only hiccup remains - a mystery.
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Radioactivity



The atoms of metals such as radium and uranium are decaying spontaneously with α-particle emission, β-particle and gamma-radiation. this phenomenon is known as spontaneous disintegration radioactivity. Nuclear radiation occurs in other forms, including protons or neutrons emission or spontaneous fission of a massive core.

Radioactive decay change a core product to another if the core has a higher binding energy than the initial nucleus nuclear decay. The difference in the binding energy (comparing the states before and after) determines which decays are energetically possible and which are not. The link appears excess energy as kinetic energy or energy of the rest mass of the decay products.

Charter nuclides, part of which is shown above, both natural known graphical representation of nuclei by the number of protons, Z, and the number of neutrons, N. All cores stable and radioactive nuclei as manmade, are shown in this letter, along with their decay properties. Nuclei with an excess of protons or neutrons compared to stable nuclei decay into stable nuclei changing protons into neutrons into protons or neutrons, or by the shedding of neutrons or protons individually or in combination. The nuclei are unstable also be nervous, that is, not in their lowest energy states. In this case, the core may fail to get rid of his excess energy without changing Z or N by emitting a gamma ray.

nuclear decay processes must meet various conservation laws, which means that the value of the amount retained after decomposition, considering all decay products, must be equal to the same quantity evaluated for core before decomposition . conserved quantities include the total energy (including ground), electrical, linear load and angular momentum, number of nucleons, and the number of leptons (sum of the number of electrons, neutrinos and antineutrinos, the antiparticles positrons-which are counted - 1).

Alpha decay

An alpha particle is identical to a helium nucleus consisting of two protons and two neutrons together.

Initially it escapes from the core atom thereof matrix invariably one of the heaviest elements, processes of quantum mechanics and is repelled more from it by electromagnetism, since both the alpha particle and the core are positively charged.

The process changes the original atom of the alpha particle is emitted in a different element.

Its mass number decreases by four atomic number two. For example, uranium-238 decay to thorium-234.

Sometimes, one of these children also radioactive nuclides will usually decomposed further by one of the other methods described below.

Beta decay

own beta decay comes in two types: β + and β-.

β- emission occurs by the transformation of one of the neutrons in the nucleus into a proton, an electron and an antineutrino. The byproducts of fission nuclear reactors often suffer β- decay, as they are likely to have an excess of neutrons.

β + decay is a similar process, but involves a proton to a neutron change, a positron and a neutrino.

gamma decay

After a nucleus undergoes decomposition alpha or beta, it is often left in an excited state with excess energy.

As an electron can move to a lower energy state by emitting a photon somewhere in the ultraviolet to infrared range, an atomic nucleus loses energy by emitting a gamma ray.

Gamma radiation is the most penetrating of the three, and will travel through several centimeters of lead.

Beta particles are absorbed by a few millimeters of aluminum, while the alpha particles will be stopped in their tracks are a few centimeters of air, or a piece of paper - but this type of radiation causes the most damage to the material arrives .

lifetimes and probability

Radioactive decay is determined by quantum mechanics - that is inherently probabilistic.

So it's impossible to work out where any particular atom will decay, but we can make predictions based on the statistical behavior of a large number of atoms.

The half-life of a radioactive isotope is the time after that, on average, will have disintegrated through the original material. After two half-lives, half of which have fallen back and one fourth of the original material remain, and so on.

Uranium and plutonium are only weakly radioactive, but have very long half-life - in the case of uranium-238, about four billion years, roughly the same as the current age of the Earth, or the remaining lifetime So Sol estimated half of the uranium-238 at all times will still be here when the sun dies.

Iodine-131 has a half-life of eight days, so that, once the fission is stopped, less than 1% of iodine-131 produced in a nuclear reactor is maintained after about eight weeks. Other iodine radioisotopes are even shorter duration.

Cesium-137, however, stick around longer. It has a half life of about 30 years, and, because of this and because it breaks through the process more dangerous beta, is believed to be the greatest risk to health if leaked into the environment.

Although some radioactive materials are artificially produced, many naturally occurring and result in the existence of a certain amount of radiation in the environment all the time - the "background radiation".

Deeply

There is a natural level of radiation around us, which comes from several sources.

Part of gamma radiation coming from space as cosmic rays. Other radiation from sources in the atmosphere, such as radon gas and some of its decay products.

There are also natural radioactive materials in the soil - and as well as the obvious elements like uranium radioactive isotopes are also common substances such as potassium and carbon.

To understand the amount of background radiation is about, which helps to distinguish between the effects on normal matter and the human body.

The amount of radiation absorbed by the non-biological material is measured in gray, equivalent to one joule of energy per kilogram of mass unit. To a biological tissue, a dose equivalent measured in sievert (Sv), depending on the type of radiation involved and the amount of damage that radiation makes particular cells affected.

The equivalent dose is the dose in Sieverts gray multiplied by a "quality factor" for the type of tissue irradiated and the type of radiation - for electrons or gamma rays, 1; for alpha particles, such as that it emerges from the radioactive decay of uranium, 20.

The average amount of radiation received from reference sources in the UK is around 2-2.5 mSv per year. Due to the preponderance of granite, which contains higher than average levels of uranium in areas such as Cornwall or Aberdeenshire may be twice that level - have not high enough to cause any concern, but high enough that facilities nuclear can not be built there as the background level and exceeds the maximum allowed limit of radiation. In some parts of the world, such as northern Iran, the background radiation is as high as 50 mSv per year.There a variety of other artificial and natural causes routine low-dose X-ray radiation.A Dental will give you a dose less than 1 mSv; A CT scan of the whole body 10 mSv.As fewer cosmic rays are stopped by the atmosphere as higher you go, the crew of a passenger plane flying between the US and Japan once a week for a year would receive an additional dose of about 9 mSv.Under normal conditions, the dose limit for nuclear industry workers is 50 mSv per year.

The effects on human health

There are two main effects on health caused by radiation, which act in the short and long term as well as shorter and longer distances.

Radiation causes health problems by killing cells in the body, and the amount and type of damage done depends on the radiation dose and the time during which the dose is spread out.

The dose limits for emergency workers in case of a nuclear accident are 100 mSv if the protection of property or 250 mSv in a salvage operation.

Between the upper and 1 Sv received in a single day, exposure can cause some symptoms of radiation poisoning, such as nausea and damage to organs including the bone marrow and lymph nodes. Up to 3 Sv these same effects are more severe with a chance of getting infections due to reduced number of white blood cells in the body - with treatment, survival is likely but will not guaranteed.Larger dose plus the above symptoms, cause bleeding, infertility and skin peeling; a dose is not more than 3.5 Sv will be fatal, and it is expected that death even with treatment doses of more than 6 Sv.The level of radiation decreases with the square of the distance from its source, so someone twice as far from an external source source will receive a quarter of the radiation.Receiving a high dose in a shorter time usually causes a more serious injury, and that higher doses kill more cells, while the body you may have had time to repair some damage over time has elapsed between doses.

However radioactive material that spread to a wider area may cause effects on the long-term health by prolonged exposure, especially if they enter the food chain or by inhalation, ingestion directly.Taking radioactive materials in the body also it presents the greatest danger of atoms that undergo alpha decay, such as alpha particles are not very penetrating and are easily absorbed by a few centimeters of air. It was alpha emitter polonium-210 that was used to murder Alexander Litvinenko in 2006.Radioactive iodine isotopes that undergo beta decay, it can accumulate in the thyroid gland and can cause thyroid cancer. Attempts to prevent this involves the distribution of pads including no radioactive iodine-127 and flooding the thyroid, which prevents the absorption of radioactive iodine.For once doses, such as medical analysis, later risk of developing cancer is estimated at about 1 20 000 mSv received.Absorbing a cumulative dose of 1 Sv for a longer time period is estimated to cause cancer finally 5% there people.However disagreement over whether very small doses comparable to the level of background radiation actually contribute to health effects.
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Gravitational Waves



A "revolutionary" new era in science just getting started with a violent event in deep space.

Today announced that researchers have detected ripples in the fabric of space called gravitational waves. It is a revolutionary breakthrough that has eluded the brightest and most sensitive minds machines Earth for decades.

Albert Einstein predicted the existence of gravitational waves 100 years ago, but thought it too weak to detect, as it rippled through the universe.

Einstein was wrong.

The news was announced on February 11 by members of the Observatory Laser Interferometer Gravitational-Wave (LIGO), 15 nations, 900-scientist, $ 1 billion experiment that sought signs of the phenomenon since 2002.

"Finally, these waves have been detected on Earth with an incredibly sensitive experiment. And, surprisingly, the source of the waves is a system of two black holes in orbit around each other, that spiral inward and collide," Cornell professor of physics and astrophysics Saul Teukolsky confirmed in a statement emailed to inside information Tech.

The researchers detected waves were created by two black holes collide and merge to form a single black hole 1.3 million years ago. When two black holes merged, they released three suns energy.

Physical Szabi Marka, a collaborator LIGO based at the University of Columbia, said Tech insiders before the announcement that detect waves "would revolutionize physics" and draw "the last undiscovered territory of Einstein."

And a collision of two black holes is a catastrophic event that could only dream of observation so far.

"Having gravitational waves as a tool will allow us to study black holes and black holes are the key to many future puzzle science," said Marka. "Actually we do not know what happens around a black hole. We do not know what happens when a black hole is another black hole. We do not know what happens when a black hole eats something."

There are many other uses of gravitational waves, now all squarely in the realm of possibility, and Marka said the next research was barreling toward us will be "spectacular."

"We will open new doors that will never be closed again," he said.

The discovery not only claims the wildest prediction of Einstein and gives astronomers a powerful new tool to probe the cosmos - from inside exploding stars to the surfaces of black holes - but also supports an idea $ 1 billion and it tells us we are on the right track to understanding how the universe works.
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Chromosome Mutation

Natures is the intention that the exact genetic information from both parents will be in the DNA of offspring in the critical stages of fertilization. However, it is possible to mutate the genetic information, in most cases, can result in fatal or negative impact on the result of the new body.

Non-Disjunction and Down's Syndrome


A well known example is the mutation nondisjunction. Nondisjunction is when the spindle fibers do not separate during meiosis, giving rise to gametes with an extra chromosome and some gametes lacking a chromosome.

If this non-disjunction of chromosome 21 of a human egg is produced, a condition called Down syndrome occurs. This is because their cells have 47 chromosomes instead of the normal chromosomes fulfilled in humans 46.

The fundamental structure of a chromosome is subject to mutation, which most likely will occur during cross in meiosis. There are a number of ways in which the chromosome structure can be changed as follows, which detrimentally change the genotype and phenotype of the organism. However, if the mutation affects an essential part of chromosome DNA, the mutation may be aborted offspring before it has a chance to be born.

The types of chromosomal mutations where the whole move genes are as follows:

Deletion of a Gene

As the name suggests, the genes of a chromosome is lost permanently as they become untethered to the centromere and are lost forever


  1. Normal chromosome before mutation
  2. Unconnected to the centromere genes become loose and lost forever
  3. New chromosome lacks certain genes which can be fatal depending on the importance of these genes are
Duplication of Genes

In this situation, the mutant genes are shown twice on the same chromosome due to the duplication of these genes. This can be an advantageous mutation has been lost or altered without the genetic information and new genes are won


  1. Normal chromosome before mutation
  2. The genes of the homologous chromosomes are copied and inserted into the genetic sequence
  3. New chromosomal genes has its initial addition of a duplicate, usually harmless



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Cloning process

Cloning is the production of genetically identical living structures to its basic structure. Genetic variations are absent. Cloning occurs naturally in asexual reproduction and vegetative microbes multiplying plants. asexually reproduced as Amoeba proteus lower animals also produce clones.

monozygotic twins are identical clones also as formed by division of two or more cells early embryo into two equal parts. Both have the same genetic characteristics. Clone is, therefore, an exact carbon copy or copies of a single live parent. artificial cloning has been achieved in the higher animals. Dolly is a clone of her mother. Cloning is the cloning of various cell types, gene cloning, microbial cloning, the cloning of plants and animal cloning.


Cell Cloning


Cell cloning is the formation of multiple copies of the same cell. Clone cells are genetically identical, morphologically and physiologically. cell cloning is necessary when:


  • The multiplication of cells having recombinant DNA (recombinant DNA) and obtain the required product as enzyme, hormone, antibody, etc., in good quantity, for example, insulin, monoclonal antibodies.
  • The biochemical analysis to be performed,
  •  Study of effect of different factors on the structure and functioning of identical cells,
  • Study the process of differentiation,
  • The maintenance of inbred lines in unicellular organisms,
  • The maintenance of rDNA and cDNA libraries of genes

Totipotency is the ability of a cell to grow into a complete organism. It is present in most plant cells. Conversely, pluripotency is the ability of a cell to develop ИПу Ot cell type in the animal body, for example, kidney cells or heart cells or nerve cells. Generally, all plants but animals are totipotent single fertilized egg (zygote) and cells in the blastocyst embryonic stem are totipotent. However, techniques have been developed for culturing animal cells.


A small sized animal tissue is taken in liquid nutrient. Protease and calcium-binding agents are added to it. The culture is stirred mechanically. Separate cells. The plant tissue can be taken similarly in a liquid nutrient medium and mechanically agitated when cells are separated. The separated cells also tend to split. With the help of a micropipette, individual fresh culture media for multiplication and the formation of clones of cells are added.

Gene Cloning


the cloning of genes is the formation of multiple copies of the same gene. DNA is extracted from an organism breaking the cells, the separation of the cores and the breakage of the nuclear envelope. The separated DNA is subjected to endonuclease. DNA fragments were passed through electrophoresis.


The selected gene is separated. It can be multiplied directly by polymerase chain reaction (PCR) using Taq polymerase. Alternatively gene can be made to match the DNA plasmid and another passenger to form recombinant DNA. The latter is inserted into a host into which the gene can be multiplied with the multiplication of host.

Applications of Gene Cloning


Medical Utility

Bacteria can be used as living plants synthesize insulin, growth hormone, interferon, vitamins and antibodies by introducing genes encoding these substances them with plasmids.

Agricultural Utility

Nitrogen fixation bacterial genes can be transferred to the main crops to increase food production without using expensive fertilizers.

Defective Genes in the Foetuses

Recombinant DNA technology is useful to know - defective genes in fetuses. Some of these genes can also be repaired.

Gene Library

The various clones representing all genes of an organism are called gene library of this organism. Gene library, a clone having a specific gene can be identified and this gene can be multiplied by the relevant clone growth in culture for study. The base sequence of this gene can be found.


From the base sequence, the amino acid sequence of a polypeptide can work on the basis of triplet code.

Microbial Cloning


Microbes multiply asexually. They produce clones. Cloning way millions of copies of the same microbe. Therefore, once a desired strain created, the microbe is multiplied and used commercially. Traditionally they have been used commercially for obtaining a number of important products such as yogurt, cheese, vinegar, lactic acid, vitamins, antibiotics and alcoholic beverages. They are constantly being improved through mutations for better performance. A number of genes have been introduced into microbes to obtain therapeutic importance bio-chemical, bio-chemical industrial products and other functions.

Plant Cloning


It takes place through vegetative propagation and tissue culture. cloning plant is useful for rapid multiplication of GM, agronomically important and rare plants. The important plants are first genetically changed through mutations, hybridization or genetic manipulation to incorporate features such as disease resistance, drought resistance, herbicide tolerance, high yield, early maturity, foodstuffs (eg , GMFS as vitamin a rich Rice, lysine rich pulse), etc. Cloning is then performed quickly through tissue culture.

meristematic zones present in the roots and shoots vertices are preferred for rapid growth. They are disinfected, washed, sectioned and placed on culture medium. Cells are separated. Each cell forms a callus which can be sub-cultured. The callus is treated with hormones to induce organogenesis and form seedlings and plants.

Animal Cloning


The formation of one or more genetically identical animals in a single animal father is called cloning animals. Hydra sprouting produce clones. Monozygotic twins (identical twins) are also clone each other. They develop from a zygote division of early embryo. Dasypus dasypus (armadillo) always produces a clone 4-8 identical offspring thereof formed from a single zygote sex.

Gurdon’s Experiment


The first successful experiments in cloning animals conducted by Gurdon (1962). He took the intestinal epithelial cells or tadpole. the core of the epithelial cell is separated. The core is inserted into the free core unfertilized egg Xenopus laevis (frog). The egg had a normal development and produces a toad. It was a clone of that toad who donated his heart.

The World’s First Cloned Mammal (Fig. 6.46 & 6.47)


Wilmut and colleagues (1997), at the Roslin Institute in Edinburgh (Scotland), produced the first cloned mammal in the world a sheep named Dolly. It was an important development in animal cloning. They took cells from the udder of a six year old sheep. unfertilized egg from another adult sheep was taken.

The egg was enucleated. Not nucleus of a cell from the udder fall was removed and inserted into the enucleated egg. In nutrient medium egg began to experience a split. The early embryo is implanted in the uterus (womb) of a third sheep. The surrogate mother gave birth to normal healthy lamb, Dolly, on 13 February 1997. Subsequently, several cloning experiments have been performed successfully.

Clone of Asian Gaur


Scientists from Massachusetts (USA) have recently cloned an endangered species, the Asian gaur (Gaur) - A horned mammal hump. It was cloned from a single skin cell taken from an Asian gaur died. The skin cell was fused with the egg of a cow, whose gene was deleted. The fused cell was transferred to the uterus (womb) to another cow. The gaur calf was born. Asian gaur is the first endangered species to be cloned and cloned the first to take shape in the womb of another species animal.

Cloning of Cattle


Japanese scientists have cloned livestock in a different way. They have succeeded in growing up to eight identical calves a fertilized cell his mother (Fig. 6.48). When the mother cow has mated with the bull, which has fertilized egg (zygote) in her womb. This cell is divided into two and then four, then eight.

This embryo is removed from the matrix. Embryonic cells are then separated using an enzyme. Every single cell is maintained in a nutrient medium, and later implanted in the uterus of a different cow "foster mother." The mother's womb must accept host cell and make it grow. Each cell grows in a healthy environment normal calf, baby.

Human Cloning


Although human cloning can help preserve an individual's desired genotype can remain a presumption in the near future due to some unresolved practical difficulties or technical and ethical reasons. Regarding the fears expressed regarding the production of human clones in the near future is concerned, it is a fact that most of the features of human behavior are acquired or learned.

Whatever we do or think is mostly a derivative activity or activity modified through learning or training. As such, human clones, if they occur in the future, it may not be behaving identically with his "clone parent". For example, no differences in behavior or the way of working of identical twins reared under different conditions of life occur. Besides this, it is known that gene expression is influenced by many factors and the environment is one of them.

Many of hereditary diseases in humans are caused by recessive genes in homozygous state. heterozygous individuals are carriers of harmful genes. The frequency of heterozygous carrier is said to be greater than the number of homozygous individuals.

Human cloning may lead to dangers of inbreeding and frequency of homozygous individuals suffering from disorders can increase marriages heterozygous clones. Therefore cloning can adversely affect genetic diversity and therefore reduce resistance to diseases of the body as seen in monoculture.

Human cloning does not rule out the involvement of male sexual partner in reproduction. However, sexual reproduction involves the fertilization of the egg by the sperm is essential for survival. genetic variation in offspring that are more adaptable and adjust for natural selection occurs. The cloning of plants and animals, therefore, may be more beneficial to mankind than human cloning.

Application of Animal Cloning


Pig is considered a suitable donor organs for transplant to humans. genetically modified pigs or swine breeds suitable can be cloned for organ transplantation. The population of endangered species of animals can be increased by cloning. Cloning can be very used to improve pedigree animals. superior races of animals can be multiplied by this technique.
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Wednesday, 17 February 2016

Human Body

Every Part of Body Play important Roll in the Human Body. All Parts of Body are Important at their own place. But Here we Describe Some very Important Parts of the Human Body. Some detail of the Important Parts of Human Body like Brain, Heart, Digestive System, Lungs and Skin etc.


Brain


Making sense of the incredible complexity of the brain is not easy. What we do know is that it is the organ that makes us human, giving people the capacity for art, language, moral judgments, and rational thought. It is also responsible for the personality of each individual, memories, movements and how they perceive the world.

All this comes from a jelly like mass of fat and protein that weighs about 3 pounds (1.4 kilograms). It is, however, one of the largest organs in the body, consisting of about 100 billion nerve cells not only put the thoughts and highly coordinated physical actions together, but regulate our unconscious, such as digestion bodily processes and the breathing.

brain nerve cells known as neurons, which constitute the so-called organ "gray matter". Neurons transmit and electrochemical signals that communicate through a network of millions of nerve fibers called axons and dendrites meet. These are "white matter." From the brain

The brain is the largest part of the brain, accounting for 85 percent of the weight of the body. The distinctive exterior surface, is deeply wrinkled cortex, consisting of gray matter. Below this is the white matter. It is the brain that causes the brain and thus human beings-so formidable. While animals such as elephants, whales and dolphins have large brains, humans have more developed brain. It's full capacity within our skulls, which surrounds the rest of the brain, with deep folds maximize intercepts the area of ​​the cortex.

The brain has two halves, or hemispheres. Furthermore, it is divided into four regions, or lobes, on each hemisphere. The frontal lobes, located behind the forehead, are involved with speech, thinking, learning, emotion and movement. Behind them are the parietal lobes that process sensory information such as touch, temperature and pain. At the rear of the brain are the occipital lobes, dealing with vision. Finally, there are the temporal lobes, near the temples, which are responsible for hearing and memory.

Movement and Balance

The second most of the brain is the cerebellum, which is below the back of the brain. It is responsible for coordinating muscle movements and control the balance. Consisting of both gray and white matter, cerebellum transmits information to the spinal cord and other parts of the brain.

Diencephalon is located in the nucleus of the brain. A complex structures more or less the size of an apricot, the two main sections are thalamus and hypothalamus. The thalamus serves as a relay station for incoming nerve impulses throughout the body which is then forwarded to the corresponding region of the brain for processing. The hypothalamus controls the hormonal secretions of the pituitary nearby. These hormones regulate growth and instinctive behavior such as eating, drinking, sex, anger, and reproduction. The hypothalamus, for example, when a new mother begins to lactate controls.

The brain stem at the base of the organ, controls the reflexes and the basic functions of life, crucial as heart rate, breathing and blood pressure. It also regulates when you feel sleepy or awake.

The brain is extremely sensitive and delicate, and so requires maximum protection. This is provided by the surrounding skull and three tough membranes called meninges. The spaces between the membranes are filled with fluid that cushions the brain and keeps it from being damaged by contact with the inside of the skull.

Heart


The heart is the engine room of the body, responsible for pumping blood to sustain life through a 60,000-mile long network of vessels (97,000 kilometer). The organ works incessantly, beating 100,000 times a day, 40 million times a year in total timing up to three billion heartbeats over an average lifetime. freshly body supply of oxygen and nutrients, while maintaining cleaning harmful wastes.

The fetal heart develops through various stages in the womb first resembles a heart fish, then a frog, which has two chambers, after a snake with three before that finally the structure of four chambers of the human heart is taken.

About the size of your own fist closed, the organ is located in the center of the chest behind the breastbone and between the lungs, in a humid chamber is protected throughout the ribcage. It consists of a special type of muscle (heart muscle) operating involuntarily, so you do not have to think about it. The heart is accelerated slowdowns automatically or in response to nerve signals from the brain that tell you how much is being exercised body. Normally, the heart contracts and relaxes between 70 and 80 times per minute, each beat of the heart's four chambers filled inside with a new round of blood.

These are two separate cavities on each side of the heart pumps, which are divided by a wall of muscle called the septum. The upper chamber of each side is called the atrium. This is connected through a sealing valve to the larger, more powerful lower chamber or ventricle. The left ventricle to pump harder, so the heartbeat of a person feels in the left chest.

When the heart contracts, the cameras become smaller, forcing blood from the atria to the ventricles first, then each ventricle into a large blood vessel connected to the top of the heart. These vessels are the two main arteries. One of them, the pulmonary artery carries blood to the lungs to receive oxygen. The other, the aorta, transports freshly oxygenated blood to the body. The vessels that carry blood to the heart are veins. The two main veins that connect to the heart are called the vena cava.

Blood delivery

Since the heart is at the center of the blood supply system, it is also essential for life. Much blood supply of oxygen from the lungs to other organs and tissues and removes carbon dioxide to the lungs, where gas is breathed. Blood also distributes power to the digestive system and the hormones of the glands. Similarly our immune cells travel in the bloodstream, the search for the infection and the blood carries waste products from the body to the kidneys and liver to be resolved and the paper.

Given many of the essential functions of the heart, it seems prudent to take care of it. However, heart disease has increased steadily over the past century, especially in industrialized countries, largely due to changes in diet and lifestyle. It has become the leading cause of death in men and women in the United States, claiming nearly 700,000 lives a year, or 29 percent of the annual total. Worldwide, 7.2 million people die of heart disease each year.

Digestive System


The digestive system is the set of tube-shaped organs that convert food into fuel our body. In total there are about 30 feet (9 meters) of these contoured auxiliary lines, starting at the mouth and ends at the anus. Along the way, food is broken down, sorted and reprocessed before being distributed throughout the body to nourish and replace cells and provide energy to the muscles.

Food on the plate has to become a puree, sticky liquid for the digestive system to break it up into its constituent parts: protein, carbohydrates, fats, vitamins and minerals. Our teeth begin the process of chewing and grinding every bite, while the language works in a ball-shaped bolus swallowing.

Moisten spit fed near the mouth of the gland begins the process of chemical digestion using specialized proteins called enzymes. Secreted at various points along the digestive tract, enzymes break large food molecules into smaller that the body is capable of absorbing molecules.

Once we swallow, digestion becomes involuntary. Food passes down the throat into the esophagus, the first of a series of hollow organs that transport their contents through muscle contractions known as peristalsis.

The esophagus empties into the stomach, a muscular chamber that mixes food with digestive juices, including pepsin, that targets proteins, and lipase, which works fat. Hydrochloric acid also helps dissolve the stomach contents while killing potentially harmful bacteria. The resulting pulp slurry-sealed chyme in the stomach by two ringlike sphincter muscles for several hours and then released in short bursts in the duodenum.

The first of the three sections of the small intestine, duodenum produces large amounts of mucus to protect the intestinal mucosa from acid chyme. Measuring about 20 feet (6 meters) in length, the small intestine, where it is the main digestion and absorption of nutrients are carried out. These nutrients are taken into the blood stream through millions of tiny fingerlike projections called villi, and transported to the liver.

What remains in the digestive tract passes into the large intestine, where it is eaten by billions of harmless bacteria and mixed with dead cells to form solid stool. Water is reabsorbed into the body, while the stool moves into the rectum awaiting expulsion.

Key players

Other organs that play a key role in digestion are the liver, gallbladder and pancreas. The pancreas is a gland organ located behind the stomach that produces a cocktail of enzymes that are pumped into the duodenum. A duct duodenum is also connected to the gallbladder. This pear shaped sac squeezing browngreen bile, a waste product collected liver fatty acid-containing material to dissolve.

The liver itself is the main chemical factory of the body, performing hundreds of different functions. nutrients absorbed into the bloodstream through the small intestine, creating glycogen which gives energy from carbohydrates and sugary conversion of dietary proteins into new proteins necessary for our blood is processed. These are stored or released as needed, such as vitamins and minerals. The liver also breaks down unwanted chemicals, like any type of alcohol consumed, which is detoxified and passed from the body as waste.

Lungs


Our lungs fuel us with oxygen gas life-sustaining body. You breathe in the air, then remove oxygen and pass into the bloodstream, where it ran to the tissues and organs that require it to operate.

Oxygen leads the process of respiration, which provides our cells with energy. Residual carbon dioxide gas is produced as a byproduct and discarded when exhaling. Without this vital link our cells die quickly and leave the body to suffocate.

Since the process air lungs, which are the only internal organs that are constantly exposed to the external environment. Central to the human respiratory system, breathing between 2,100 and 2,400 gallons (8,000 and 9,000 liters) of air each day, the amount needed to oxygenate 2,400 gallons (9,000 liters) about blood being pumped by heart all the days.

The intricate construction

Our two lungs are composed of a complex network of pipes, which are suspended on either side of the heart into the chest cavity in a framework of elastic fibers. Air is drawn through the mouth and nose, the latter acting as an air filter trapping dust particles in their hair. The air is heated before passing through the trachea, where it splits at the bottom between two airways called bronchi leading to one of the lungs.

In the lungs, the division of the bronchi mucus lining like the branches of a tree in tens of thousands of increasingly smaller tubes (bronchioles), which connect to small sacs called alveoli. The average adult lungs contain about 600 million of these spongy, air-filled structures. There is enough in one lung alveoli to cover an area roughly the size of a tennis court.

The alveoli are where gas exchange takes central place. Air bags are surrounded by a dense network of small blood vessels or capillaries, which connect to the heart. Which they relate to the pulmonary arteries carry deoxygenated blood that needs to be updated. Oxygen passes through the incredibly thin walls of the alveoli into the capillaries and then brought back to the heart via the pulmonary veins. At the same time, carbon dioxide is removed from the blood through the same diffusion process. This residual gas is expelled as we exhale.

The rate at which we breathe is controlled by the brain, which is quick to detect changes in gas concentrations. This is definitely in the brain of interests which is the largest oxygen consumer in our body and the first organ to suffer if there is a shortage.

In and out

The actual work of breathing by the diaphragm, the muscle sheet between the thorax and the abdomen is mostly done. These muscles contract when we inhale, the expansion of the lungs and drawing in the air. We exhale simply by relaxing the diaphragm; lungs deflate like balloons.

The lungs are delicate and vulnerable to a number of diseases organs. The most common of them in Western countries are emphysema and bronchitis, which are often caused by smoking. The tubes inside the lungs become chronically inflamed, producing excess mucus. Smoking can also lead to lung cancer in the world major cancer, which is diagnosed in 1.4 million people a year.

Skin


Body organs are not all internal and brain or heart. There is one that we use abroad. The skin is our largest organ-adult take about 8 pounds (3.6 kilograms) and 22 square feet (2 meters square) of it. This fleshy covering does more than make us look presentable. In fact, without it, we would literally evaporate.

Skin acts as a waterproof shield, insulation, protecting the body against extreme temperatures, damaging sunlight and harmful chemicals. Also emanating antibacterial substances that prevent infection and produces vitamin D for converting calcium in bones healthy. The skin also is a huge full sensor brain nerves to maintain contact with the outside world. At the same time, the skin allows the free movement, proving itself an incredibly versatile organ.

The skin consists of three layers. The outermost is the epidermis. This consists mainly of cells called keratinocytes, made from the protein keratin hard (also the material in the hair and nails). Keratinocytes are several layers to constantly grow outward as the outer cells die and slough off. It takes about five weeks to the newly created to work their way to the surface cells. This cover dead skin known as the stratum corneum or horny layer, and its thickness varies considerably, being more than ten times thicker in the soles of the feet around the eyes. The epidermis contains defensive Langerhans cells, which alerts the body's immune system to viruses and other infectious agents.

The epidermis is attached to a deeper layer of skin known as the dermis below, which gives the body the strength and elasticity due to collagen and elastin fibers. Here blood vessels help regulate body temperature by increasing blood flow to the skin to allow the heat to escape, or restricting the flow when it is cold. A network of nerve receptors and feelings collect fibers such as touch, temperature and pain transmission to the brain.

The dermis contains hair follicles and glands with ducts which pass through the skin. Sweat glands lower the internal temperature through perspiration, while ridding the body of waste fluids urea and lactate. The apocrine glands, which develop during puberty, produce a scented sweat linked to sexual attraction which can also cause body odor, especially around the armpits. The sebaceous glands secrete oil-like sebum to lubricate the hair and skin.

base layer of the skin is the subcutaneous tissue, which includes a seam of fat established as a reserve fuel in case of food shortages. It also works as an insulator and absorbs bumps and drops us.

Skin color

skin color is caused by melanin, a pigment produced in the skin to protect us from ultraviolet (UV) potentially carcinogenic ultraviolet sun. People with dark skin produce more and melanin particles deeper color. People with darker skin are native to tropical regions, particularly those with few areas of dense forest.

White skin is an adaptation that is found in people of northern latitudes where sunlight is relatively weak. Here dark skin benefits are outweighed by the need to build strong bones Vitamin D, produced by exposure to UV rays. But warm sunny environments carry the risk of serious skin damage. Australia, where most of the population of northern European descent, have higher rates of skin cancer in the world, representing more than 80 percent of all cancers diagnosed each year there.
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Tuesday, 16 February 2016

Science of Earthquakes

What is an earthquake?

An earthquake is what happens when two blocks of the earth suddenly slip past each other. The surface slide is called the fault plane or missing. The location below the surface of the earth where the earthquake starts is called the hypocenter, and the location just above it on the surface of the Earth is called the epicenter.

Sometimes a preliminary earthquake tremors. These are smaller earthquakes that occur in the same place as the largest earthquake to follow. Scientists can not say that an earthquake is a foreshock until the larger earthquake. The largest, main earthquake is called the mainshock. Mainshocks always have aftershocks that followed. These are smaller earthquakes that occur later in the same place as the main quake. Depending on the size of the main shock, aftershocks may continue for weeks, months and even years after the main shock.

What causes earthquakes and where do they happen?

The earth has four main layers: the inner core, outer core, mantle and crust. (Figure 2) The crust and upper mantle form a thin skin on the surface of our planet. However, this skin is not all in one piece is - which is composed of many pieces like a puzzle that covers the surface of the earth. (Figure 3) Not only that, but these pieces of the puzzle are still moving slowly, sliding over each other and collide. We call these puzzle pieces tectonic plates, and the edges of the plates are called plate boundaries. The plate boundaries are composed of many defects, and most of earthquakes worldwide occur on these faults. Since the edges of the plates are rough, they get stuck while the rest of the plate continues moving. Finally, when the plate has moved far enough, the UNSTICK edges in one of the faults and there is an earthquake.


Why does the earth shake when there is an earthquake?

While the sides of the faults are stuck together, and the rest of the block is moving, the energy normally blocks slide over one another is being stored up. When the force of the moving blocks finally overcomes the friction of the jagged edges of the fault and is off, all that stored energy is released. Energy radiates outward from the fault in all directions in the form of seismic waves like ripples in a pond. Seismic waves shake the earth as they move through it, and when the waves reach the surface of the earth, shaking the ground and anything on it, like our homes and us! (See P & S wave box).

How are earthquakes recorded?

Earthquakes are recorded by instruments called seismographs. The recording you make is called a seismogram. (Figure 4) The seismograph has a base set firmly on the ground, and a heavy weight hanging free. When an earthquake causes the ground to shake, based seismograph also shake, but the weight hanging does not. Instead, the spring or rope hanging from absorbs the movement. The difference in position between the part of the seismograph shaking and stationary part is what is recorded.



How do scientists measure the size of earthquakes?

The size of an earthquake depends on the size of the ball and the amount of slip on the fault, but that's not something that scientists can be simply measured with a tape measure from defects are many kilometers beneath the surface of the earth. So how do you measure an earthquake? They use recordings made on seismograms seismographs on the surface of the earth to determine how big was the earthquake (Figure 5). A short wavy line means not much wiggle a small earthquake, and a wavy line much longer wagging means a great earthquake. The length of the undulation depends on the size of the damage, and the size of the maneuver depends on the amount of slip.

The size of the earthquake is called its magnitude. It is a magnitude for each earthquake. Scientists also talk about the intensity of the movement of an earthquake, and this varies depending on where you are in the earthquake.

How can scientists tell where the earthquake happened?

Seismograms are useful for earthquake location also, and be able to see the P wave and S wave is important. He has learned from P & S waves at each ground motion in different ways as they travel through it. P waves are also faster than S waves, and this is what allows us to tell where it was an earthquake. To understand how this works, let's compare the P and S waves and lightning. Light travels faster than sound, so that during a thunderstorm I first see lightning and then hear thunder. If you are close to the lightning, the thunder will boom just after the lightning, but if you are away from the lightning may have several seconds before hearing thunder. The farther you are from the storm, the longer it will take between lightning and thunder.

P waves are like lightning, and S waves are like thunder. P waves travel faster and shake the ground where you are first. Then the S waves are and shake the ground as well. If you are near the earthquake, the P and S wave is one after the other, but if you are away, there will be more time between the two. Looking at the amount of time between the P and S wave on a seismogram recorded on a seismograph, scientists can know how far the earthquake was there. However, they may not know in which direction the earthquake seismograph was, but how far it was. If you draw a circle on a map around the station where the radius of the circle is the determined distance to the earthquake, they know that the earthquake is located somewhere in the circle. But where?

The scientists then used a method called triangulation to determine exactly where the earthquake was (Figure 6). It's called triangulation because a triangle has three sides, and takes three seismographs to locate an earthquake. If you draw a circle on a map in three different seismometers where the radius of each is the distance from the earthquake that station, the intersection of the three circles is the epicenter.

Can scientists predict earthquakes?

No, and it is unlikely to ever be able to predict them. Scientists have tried many different ways of predicting earthquakes, but none have succeeded. In any particular fault, scientists know there will be another earthquake at some point in the future, but have no way of knowing when it will happen.

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Human Brain: Origin, Evolution, Function

Brain

The brain is one of the most complex and magnificent organ in the human body. Our brain gives us the awareness of ourselves and our environment, processing a steady stream of sensory data. our muscle movements controlled, secretions from the glands of ours, and even breathing and internal temperature. Every creative thought, feeling, and the plan is developed by our brain. brain neurons recorded memory of every event in our lives.

In fact, the human brain is so complicated that it is still an exciting frontier in the study of the body; doctors, psychologists and scientists continually strive to learn exactly how many brain structures work closely together to create our powerful human mind.

Anatomy of the Brain

There are different ways of dividing the brain anatomically regions. Let's use a common method and divide the brain into three main regions based on embryonic development: the forebrain, midbrain and hindbrain. In these divisions:

  • The forebrain (forebrain o) consists of our amazing brain, the thalamus, the hypothalamus and the pineal gland among other characteristics. You neuroanatomists call the brain area of ​​the telencephalon and diencephalon use the term (or interbrain) to refer to the area where our thalamus, hypothalamus and the pineal gland resides.

  • The midbrain (or midbrain), located near the center of the brain between the diencephalon and hindbrain, consists of a portion of the brain stem.

  • Hindbrain (or hindbrain) consists of the remaining brainstem and cerebellum and pons our. Neuroanatomists have a word to describe the brain stem sub-region of our hindbrain, calling it the myelencephalon, as they use the word in reference to our hindbrain cerebellum and pons collectively.

Before exploring these different brain regions, first let's define the major types of cells and tissues that are the building blocks of all.

Histology

Brain cells can be divided into two groups: neurons and glia.

Neurons, or nerve cells, are the cells that perform all communication and processing in the brain. Sensory neurons that enter the brain from the peripheral nervous system provide information about the condition of the body and its surroundings. Most of the neurons in the gray matter of the brain are interneurons, which are responsible for the integration and processing of information to the brain by sensory neurons. Interneurons send signals to motor neurons, which carry signals to muscles and glands.

Glia or glial cells act as helper cells of the brain; support and protect neurons. In the brain there are four types of glial cells: astrocytes, oligodendrocytes, microglia and ependymal cells.

  • Astrocytes protect neurons by filtering nutrients from the blood and preventing chemicals and leaving pathogens brain capillaries.
  • Oligodendrocytes surround the axons of the neurons in the brain to produce the insulation called myelin. nerve myelinated axons transmit signals much faster than unmyelinated axons, oligodendrocytes so accelerate the rate of communication of the brain.
  • Microglia act as some white blood cells to attack and destroy pathogens that invade the brain.
  • Ependymal cells and capillaries of the choroid plexus and blood plasma filter are aligned to produce cerebrospinal fluid.
Brain tissue can be divided into two broad classes: gray matter and white matter.

  • Gray matter is made of myelinated neurons especially, most of which are interneurons. Gray matter regions are the areas of nerve connections and processing.
  • The white matter is mainly of myelinated neurons connecting gray matter regions of one another and with the rest of the body. myelinated neurons transmit nerve signals much faster than unmyelinated axons do. Acts of white matter as the information highway of the brain to speed up connections between different parts of the brain and body.

HINDBRAIN (RHOMBENCEPHALON)

Brainstem

Connect the brain to the spinal cord, brain stem is the lower part of the brain. Many of the basic survival of brain functions are controlled by the brainstem.

The brain stem consists of three regions: the medulla, pons and midbrain. Similar to a network of gray and white matter mixed structure known as the reticular formation in the three regions of the brainstem. The reticular formation controls muscle tone in the body and acts as a switch between consciousness and sleep in the brain.

The medulla is a roughly cylindrical mass of nervous tissue that connects to the spinal cord at its lower edge and the bulge in its upper edge. Spinal contains mostly white matter nerve signals carrying the ascending and descending brain spinal cord. In several regions of spinal gray matter that process involuntary body functions related to homeostasis. The cardiovascular center of the spinal controls the levels of pressure and oxygen in the blood and regulates heart rate to provide sufficient supply of oxygen to body tissues. Downtown medullary rhythmicity controls the rate of breathing to provide oxygen to the body. Vomiting, sneezing, coughing and swallowing reflexes are coordinated in this region of the brain also.

The bridge is the region of the brainstem found above the medulla, below the midbrain and cerebellum above. With the cerebellum, it forms what is called the hindbrain. About an inch long and big and a little wider than the medulla, pons acts as a bridge for nerve signals traveling to and from the cerebellum and transmits signals between the upper regions of the brain and spinal and spinal spinal.

Cerebellum

The cerebellum is a wrinkled, hemispherical region of the back of the brain located below the brain and brain stem. The outer layer of the cerebellum known as the cerebellar cortex is made of neatly folded gray matter that provides the processing power of the cerebellum. Deep in the cerebellar cortex is a layer in a tree of white matter called Arbor Vitae, meaning "tree of life." The arbor vitae connects the processing regions of the cerebellar cortex to the rest of the brain and body.

The cerebellum helps control motor, such as balance, posture and coordination of the complex muscular activities functions. The cerebellum receives sensory information from the muscles and joints of the body and uses this information to keep the body balanced and maintain posture. The cerebellum also controls the timing and finesse of complex motor actions such as walking, writing and speaking.

MIDBRAIN (MESENCEPHALON)

Midbrain, also known as the midbrain is the uppermost region of the brainstem. Found between the protrusion and diencephalon, midbrain can be subdivided into two main regions: the tectum and brainstem.

  • The tectum is the posterior region of the midbrain, which contains relays for reflections that involve auditory and visual information. The pupillary reflex (adjusting light intensity), accommodation reflex (focus on near or far objects), and scare reflexes are some of the many reflections relayed through this region.
  • The formation of the anterior midbrain, the brainstem contain many nerve pathways and substantia nigra. nerve tracts passing through connecting regions brainstem and thalamus of the brain to the spinal cord and lower regions of the brainstem. The substantia nigra is one region of the dark melanin-containing neurons is involved in the inhibition of movement. Degeneration of the substantia nigra leads to a loss of Parkinson disease known as motor control.

FOREBRAIN (PROSENCEPHALON)

Diencephalon

Anterior superior midbrain and is the region known as the interbrain or diencephalon. Thalamus, hypothalamus and pineal gland make major regions of the diencephalon.

  • The thalamus is a pair of lower oval masses of gray matter to the lateral ventricles and surrounding the third ventricle. Sensory neurons that enter the brain relay format of the peripheral nervous system neurons in the thalamus following the cerebral cortex. Thus the thalamus acts as the switchboard operator brain by routing to the correct sensory regions of the cerebral cortex entries. The thalamus plays an important role in learning by routing sensory information processing centers of the brain and memory.
  • The hypothalamus is a region lower than the thalamus and brain pituitary gland located. The hypothalamus acts as the control center of the brain in body temperature, hunger, thirst, blood pressure, heart rate and hormone production. In response to changes in body condition detected by sensory receptors, the hypothalamus sends signals to the glands, smooth muscles, and the heart to counteract these changes. For example, in response to increases in body temperature, the hypothalamus stimulates the secretion of sweat from the sweat glands in the skin. The hypothalamus also sends signals to the cerebral cortex to produce feelings of hunger and thirst when the body lacks food or water. These signals stimulate the conscious mind to get food or water to correct this situation. The hypothalamus also directly controls the pituitary gland by producing hormones. Some of these hormones, such as oxytocin and antidiuretic hormone, is produced in the hypothalamus and stored in the posterior pituitary gland. Other hormones, such as releasing and inhibiting hormones are secreted in the blood to stimulate or inhibit hormone production in the anterior pituitary gland.
  • The pineal gland is a small gland located behind the thalamus in a sub-region called the thalamus. The pineal gland produces the hormone melatonin. light striking the retina of the eye sends signals to inhibit the function of the pineal gland. In the darkness, the pineal gland secretes melatonin, which has a sedative effect on the brain and helps induce sleep. This function of the pineal gland helps explain why darkness is sleep induction and light tends to disrupt sleep. Babies produce large amounts of melatonin, allowing them to sleep up to 16 hours per day. The pineal gland produces less melatonin with age, resulting in difficulty sleeping during adulthood.

Cerebrum

The largest region of the human brain, the brain controls higher brain functions such as language, logic, reasoning and creativity. Diencephalon surrounds the brain and is higher than the cerebellum and brainstem. A deep groove called the longitudinal fissure runs sagittal in the center of the brain, dividing the brain into the left and right hemispheres. Each hemisphere can be divided into four lobes: frontal, parietal, temporal and occipital. The lobes are named for the skull bones that cover them.

The surface of the brain is a twisted layer of gray matter known as the cerebral cortex. Most brain processing is carried out within the cortex. The protrusions of the crust are called convolutions (singular: gyrus), while the slits are called grooves (singular: groove).

Deep to the cortex is a layer of the cerebral white matter. The white matter contains the connections between brain regions and between the brain and the body. A band of white matter called the corpus callosum connects the left and right brain hemispheres and allows communicate with each other.

Deep in the cerebral white matter are several regions of gray matter that make up the basal ganglia and limbic system. The nuclei of the base, including the globus pallidus, striatum and the subthalamic nucleus, working together with the substantia nigra of the midbrain to regulate and control muscle movements. Specifically, these regions help control muscle tone, posture and skeletal muscle subconscious. The limbic system is another group of deep gray matter regions, including the hippocampus and amygdala, which are involved in memory, survival, and emotions. The limbic system helps the body to react to emergency situations with highly emotional, almost involuntary rapid action.

With so many vital functions under the control of one amazing body - and so many important functions performed at its outer layers - how our body to protect the brain from damage? Our skull clearly offers some protection, but what protects the brain from skull itself? Keep reading!

Meninges

Three layers of tissue, known collectively as the meninges, surround and protect the brain and spinal cord.

  • The dura form leather, outermost layer of the meninges. irregular dense connective tissue made of collagen fibers gives the dura difficult strength. Dural a pocket that surrounds the brain and spinal cord to keep the cerebrospinal fluid and prevent mechanical damage to the soft nerve tissue is formed. The dura mater name comes from the Latin for "tough mother" because of their protective nature.
  • Arachnoid found lining the inside of the dura. Much thinner and more delicate than the dura, which contains many fine fibers that connect the dura mater and the pia mater. Arachnoid name comes from the Latin for "Mother Spider" because its fibers resemble a spider web. Below the arachnoid is a region filled with liquid known as the subarachnoid space.
  • As the innermost layer of the meninges, the pia mater rests directly on the surface of the brain and spinal cord. The pia many blood vessels provide nutrients and oxygen to the nerve tissue of the brain. The pia mater also helps regulate the flow of cerebrospinal fluid materials from the bloodstream and nervous tissue.

Cerebrospinal Fluid

Cerebrospinal fluid (CSF) - a clear fluid surrounding the brain and spinal cord - offers many important functions in the central nervous system. Instead of being firmly anchored in the bones surrounding the brain, spinal cord and float inside the LCR. CSF filled subarachnoid space and exerts pressure on the outside of the brain and spinal cord. CSF pressure acts as a stabilizer and shock absorber for the brain and spinal cord, and floating within the cavities of the skull and vertebrae. Within the brain, CSF filled small cavities called ventricles expand under pressure to lift CSF and brain tissue inflate soft.

Cerebrospinal fluid is produced in the brain capillaries coated with ependymal cells known as the choroid plexus. Blood plasma passing through the capillaries is filtered by ependymal cells and is released into the subarachnoid space and CSF. The CSF contains glucose, oxygen and ions, which helps distribute throughout the nervous tissue. CSF also carries away waste products of nerve tissue.

After circulating around the brain and spinal cord, CSF enters small structures called arachnoid villi where it is reabsorbed into the bloodstream. arachnoid villi are finger-shaped extensions of the arachnoid passing through the dura and the superior sagittal sinus. The superior sagittal sinus is a vein running through the longitudinal slot in the brain and carries blood and cerebral spinal fluid back to the heart.

Physiology of the Brain

Metabolism

Despite weighing only about 3 pounds, the brain consumes as much as 20% of the oxygen and glucose taken by the body. Nerve tissue in the brain has a very high metabolic rate, due to the large number of decisions and processes that occur in the brain at any given time. The large volumes of blood must be constantly delivered to the brain in order to maintain the proper brain function. Any interruption in the blood supply to the brain very quickly leads to dizziness, disorientation, and finally unconsciousness.

Sensory

The brain receives information about the condition of the body and its environment from all sensory receptors in the body. All this information is entered into the sensory areas of the brain, which collect this information to create a perception of internal and external conditions of the body. Part of this sensory information is the autonomous sensory information, which tells the brain subconsciously about the condition of the body. body temperature, heart rate and blood pressure are all autonomous senses that the body receives. Other information is somatic sensory information that the brain is conscious. Touch, sight, sound and hearing are all examples of somatic senses.

Motor Control

Our brain directly controls almost every movement in the body. A region of the cerebral cortex known as the engine area sends signals to the skeletal muscles to produce all voluntary movements. Basal ganglia of the brain and gray matter in the brain stem helps to control these movements unconsciously avoid extraneous movements are undesirable. The cerebellum helps with timing and coordination of these movements during complex movements. Finally, the smooth muscle tissue, cardiac muscle, and glands are stimulated by motor outputs of the autonomous regions of the brain.

Processing

Once entered sensory information in the brain, the association areas of the brain will work processing and analyzing this information. Sensory information is combined, evaluated and compared to previous experiences, providing the brain with an accurate picture of conditions. Association areas also work to develop action plans that are sent to motor regions of the brain in order to produce a change in the body through the muscles or glands. association areas also work to create our thoughts, plans and personality.

Learning and Memory

The brain needs to store many different types of information received from the senses and develops through thought in the areas of partnership. Information is stored in the brain in a few different ways depending on their source and time it takes. Our brain keeps short-term memory to keep track of the tasks that the brain is currently being undertaken. The short-term memory is believed to consist of a group of neurons that stimulate each other in a loop to keep data in memory of the brain. New information replaces the old information in short-term memory within a few seconds or minutes, unless the information is transferred to the long-term memory.

The long-term memory is stored in the brain from the hippocampus. The hippocampus transfers information from short-term memory to storage memory regions of the brain, especially in the cerebral cortex of the temporal lobes. The related motor skills (known as procedural memory) memory is stored by the basal ganglia and cerebellum.

Homeostasis

The brain acts as the control center of the body by maintaining the homeostasis of many different functions such as breathing, heart rate, body temperature, and hunger. The brainstem and hypothalamus are more concerned with homeostasis brain structures.

In the brainstem, medulla oblongata contains the cardiovascular center that monitors the levels of dissolved carbon dioxide and oxygen in the blood, with the blood pressure. The cardiovascular center adjusts the heart rate and dilating the blood vessels to maintain healthy levels of gases dissolved in the blood and maintain a healthy blood pressure. The center of the spinal cord rhythmicity controls the levels of oxygen and carbon dioxide in the blood and respiration rate adjusted to maintain these levels in balance.

The hypothalamus controls the homeostasis of body temperature, blood pressure, sleep, thirst and hunger. Many autonomic receptors for temperature, pressure, and dosing means in the hypothalamus. The hypothalamus processes sensory information it receives and sends the output to the autonomic effectors in the body, such as sweat glands, heart and kidneys.

Sleep

While sleep may seem to be a time of rest for the brain, this organ is actually very active during sleep. The hypothalamus maintains biological clock 24 hours body, known as the circadian clock. When the circadian clock indicates that it is time to sleep, it signals the reticular activating system of the brain stem to reduce the stimulation of the cerebral cortex. Reduction in the stimulation of the cortex leads to a feeling of drowsiness and eventually leads to sleep.

In a state of sleep, the brain fails to maintain awareness, reduce some of their sensitivity to sensory stimuli, relaxes the skeletal muscles, and complete many administrative functions. These include consolidating administrative functions and storage memory, sleep, and development of nerve tissue.

There are two main stages: the dream of rapid eye movement (REM) and non-rapid eye movement (NREM). During REM sleep the body is paralyzed while the eyes move back and forth quickly. Sleep is common during REM sleep is believed that some memories are stored during this phase. NREM sleep is a period of slow eye movement or no movement of the eyes, culminating in a deep sleep in the lower brain electrical activity. Dreaming during NREM sleep is rare, but the memories are processed and stored during this time.

Reflexes

A reflex is an involuntary to a form of internal or external stimulus rapid reaction. Many reflexes in the body are integrated in the brain, including the pupillary light reflex, coughing and sneezing. Many reflexes protect the body from damage. For example, cough and sneeze to clear the airways of the lungs. Other reflexes help the body respond to stimuli, such as the adjustment of pupils to bright or dim light. All reflections occur quickly without going through the control centers of the cerebral cortex and integration into the nether regions of the brain such as the environment or limbic brain system.
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