ARDRAM
Thursday 19 January 2017
Parts of the Brain and Their Functions
The human brain is a specialized organ that is ultimately responsible for all thought and movement that the body produces. Many different parts of the brain and their functions are shown in the article. Each part has a unique function that allows humans observe and interact with their environment effectively.
The human brain is ultimately responsible for all thought and movement that the body produces. This allows humans to successfully interact with their environment, by communicating with others and interacting with inanimate objects near their position. If the brain is not functioning properly, the ability to move, generate accurate sensory information or speak and understand language can be damaged as well.
The brain is made up of nerve cells which interact with the rest of the body through the spinal cord and nervous system. These cells relate information back to specific centers of the brain where it can be processed and an appropriate reaction can be generated. Several chemicals are also located in the brain, which help the body maintain homeostasis, or a sense of overall comfort and calm as its basic needs are met. Keeping these chemicals balanced and the nerve cells firing properly are essential to healthy brain function.
Frontal Lobe: The frontal lobe is one of four lobes in the cerebral hemisphere. This lobe controls a several elements including creative thought, problem solving, intellect, judgment, behavior, attention, abstract thinking, physical reactions, muscle movements, coordinated movements, smell and personality.
Parietal Lobe:Located in the cerebral hemisphere, this lobe focuses on comprehension. Visual functions, language, reading, internal stimuli, tactile sensation and sensory comprehension will be monitored here.
Temporal Lobe: The temporal lobe controls visual and auditory memories. It includes areas that help manage some speech and hearing capabilities, behavioral elements, and language. It is located in the cerebral hemisphere.
Amygdala:The amygdala helps the body responds to emotions, memories and fear. It is a large portion of the telencephalon, located within the temporal lobe which can be seen from the surface of the brain. This visible bulge is known as the uncus.
Hippocampus: This portion of the brain is used for learning memory, specifically converting temporary memories into permanent memories which can be stored within the brain. The hippocampus also helps people analyze and remember spatial relationships, allowing for accurate movements. This portion of the brain is located in the cerebral hemisphere.
Hypothalamus:The hypothalamus region of the brain controls mood, thirst, hunger and temperature. It also contains glands which control the hormonal processes throughout the body.
Thalamus:The Thalamus is located in the center of the brain. It helps to control the attention span, sensing pain and monitors input that moves in and out of the brain to keep track of the sensations the body is feeling.
Midbrain:The midbrain, also known as the mesencephalon is made up of the tegmentum and tectum. These parts of the brain help regulate body movement, vision and hearing. The anterior portion of the midbrain contains the cerebral peduncle which contains the axons that transfer messages from the cerebral cortex down the brain stem, which allows voluntary motor function to take place.
Pons: This portion of the metencephalon is located in the hindbrain, and links to the cerebellum to help with posture and movement. It interprets information that is used in sensory analysis or motor control. The pons also creates the level of consciousness necessary for sleep.
Medulla: The medulla or medulla oblongata is an essential portion of the brain stem which maintains vital body functions such as the heart rate and breathing.
The brain is made up of nerve cells which interact with the rest of the body through the spinal cord and nervous system. These cells relate information back to specific centers of the brain where it can be processed and an appropriate reaction can be generated. Several chemicals are also located in the brain, which help the body maintain homeostasis, or a sense of overall comfort and calm as its basic needs are met. Keeping these chemicals balanced and the nerve cells firing properly are essential to healthy brain function.
Parts of the Brain and Their Functions
Cerebrum
The cerebrum is the largest portion of the brain, and contains tools which are responsible for most of the brain's function. It is divided into four sections: the temporal lobe, the occipital lobe, parietal lobe and frontal lobe. The cerebrum is divided into a right and left hemisphere which are connected by axons that relay messages from one to the other. This matter is made of nerve cells which carry signals between the organ and the nerve cells which run through the body.Frontal Lobe: The frontal lobe is one of four lobes in the cerebral hemisphere. This lobe controls a several elements including creative thought, problem solving, intellect, judgment, behavior, attention, abstract thinking, physical reactions, muscle movements, coordinated movements, smell and personality.
Parietal Lobe:Located in the cerebral hemisphere, this lobe focuses on comprehension. Visual functions, language, reading, internal stimuli, tactile sensation and sensory comprehension will be monitored here.
- Sensory Cortex- The sensory cortex, located in the front portion of the parietal lobe, receives information relayed from the spinal cord regarding the position of various body parts and how they are moving. This middle area of the brain can also be used to relay information from the sense of touch, including pain or pressure which is affecting different portions of the body.
- Motor Cortex- This helps the brain monitor and control movement throughout the body. It is located in the top, middle portion of the brain.
- Wernicke's Area- This portion of the temporal lobe is formed around the auditory cortex. While scientists have a limited understanding of the function of this area, it is known that it helps the body formulate or understand speech.
- Broca's Area- This area of the brain controls the facial neurons as well as the understanding of speech and language. It is located in the triangular and opercular section of the inferior frontal gyrus.
Cerebellum
This is commonly referred to as "the little brain," and is considered to be older than the cerebrum on the evolutionary scale. The cerebellum controls essential body functions such as balance, posture and coordination, allowing humans to move properly and maintain their structure.Limbic System
The limbic system contains glands which help relay emotions. Many hormonal responses that the body generates are initiated in this area. The limbic system includes the amygdala, hippocampus, hypothalamus and thalamus.Amygdala:The amygdala helps the body responds to emotions, memories and fear. It is a large portion of the telencephalon, located within the temporal lobe which can be seen from the surface of the brain. This visible bulge is known as the uncus.
Hippocampus: This portion of the brain is used for learning memory, specifically converting temporary memories into permanent memories which can be stored within the brain. The hippocampus also helps people analyze and remember spatial relationships, allowing for accurate movements. This portion of the brain is located in the cerebral hemisphere.
Hypothalamus:The hypothalamus region of the brain controls mood, thirst, hunger and temperature. It also contains glands which control the hormonal processes throughout the body.
Thalamus:The Thalamus is located in the center of the brain. It helps to control the attention span, sensing pain and monitors input that moves in and out of the brain to keep track of the sensations the body is feeling.
Brain Stem
All basic life functions originate in the brain stem, including heartbeat, blood pressure and breathing. In humans, this area contains the medulla, midbrain and pons. This is commonly referred to as the simplest part of the brain, as most creatures on the evolutionary scale have some form of brain creation that resembles the brain stem. The brain stem consists of midbrain, pons and medulla.Midbrain:The midbrain, also known as the mesencephalon is made up of the tegmentum and tectum. These parts of the brain help regulate body movement, vision and hearing. The anterior portion of the midbrain contains the cerebral peduncle which contains the axons that transfer messages from the cerebral cortex down the brain stem, which allows voluntary motor function to take place.
Pons: This portion of the metencephalon is located in the hindbrain, and links to the cerebellum to help with posture and movement. It interprets information that is used in sensory analysis or motor control. The pons also creates the level of consciousness necessary for sleep.
Medulla: The medulla or medulla oblongata is an essential portion of the brain stem which maintains vital body functions such as the heart rate and breathing.
Tuesday 8 November 2016
ATMOSPHERE
By volume , dry dry air contains 78.09% nitrogen,20.95% oxygen, 0.93% argon, 0.04% carbondioxide, and small amounts of other gases .Air is also contains a variable amount of watervapour, on average around 1% at sea level,and 0.4% over the entire atmosphere. Air content and atmospheric pressure vary at different layers , and air suitable for use in photosynthesis by terrestrial animals is found only in Earth’s troposphere and in artificial atmospheres
The study of Earth’s
atmosphere and its processes is called atmospheric science (aerology). Early
pioneers in the field include Leon Teisserence dc Bort
and Richard Assmann.
LAYERS
OF ATMOSPHERE
The atmosphere is comprised of layers based on temperature. These layers
are the troposphere, stratosphere, mesosphere and thermosphere. A further
region at about 500 km above the Earth's surface is called the exosphere.
The different layers of the
atmosphere
The atmosphere can be divided
into layers based on its temperature, as shown in the figure below. These
layers are the troposphere, the stratosphere, the mesosphere and the thermosphere.
A further region, beginning about 500 km above the Earth's surface, is called
the exosphere.
The red line on
the figure below shows how temperature varies with height (the temperature
scale is given along the bottom of the diagram). The scale on the right shows
the pressure. For example, at a height of 50 km, the pressure is only about one
thousandth of the pressure at the ground.
The Troposphere
This is the
lowest part of the atmosphere - the part we live in. It contains most of our
weather - clouds, rain, snow. In this part of the atmosphere the temperature
gets colder as the distance above the earth increases, by about 6.5°C per
kilometre. The actual change of temperature with height varies from day to
day, depending on the weather.
The troposphere
contains about 75% of all of the air in the atmosphere, and almost all of the
water vapour (which forms clouds and rain). The decrease in temperature with
height is a result of the decreasing pressure. If a parcel of air moves upwards
it expands (because of the lower pressure). When air expands it cools. So air
higher up is cooler than air lower down.
The lowest part
of the troposphere is called the boundary layer. This is where
the air motion is determined by the properties of the Earth's
surface. Turbulence is generated as the wind blows over the Earth's
surface, and by thermals rising from the land as it is heated by the sun.
This turbulence redistributes heat and moisture within the boundary layer, as
well as pollutants and other constituents of the atmosphere.
The top of the
troposphere is called the tropopause. This is lowest at the poles, where it is
about 7 - 10 km above the Earth's surface. It is highest (about 17 -
18 km) near the equator.
The Stratosphere
This extends
upwards from the tropopause to about 50 km. It contains much of the ozone in
the atmosphere. The increase in temperature with height occurs because of
absorption of ultraviolet (UV) radiation from the sun by this ozone.
Temperatures in the stratosphere are highest over the summer pole, and lowest
over the winter pole.
By absorbing
dangerous UV radiation, the ozone in the stratosphere protects us from skin
cancer and other health damage. However chemicals (called CFCs or freons, and
halons) which were once used in refrigerators, spray cans and fire
extinguishers have reduced the amount of ozone in the stratosphere,
particularly at polar latitudes, leading to the so-called "Antarctic ozone
hole".
Now humans have stopped making
most of the harmful CFCs we expect the ozone hole will eventually recover over
the 21st century, but this is a slow process.
The Mesosphere
The region above
the stratosphere is called the mesosphere. Here the temperature again decreases
with height, reaching a minimum of about -90°C at the "mesopause".
The Thermosphere
and Ionosphere
The thermosphere
lies above the mesopause, and is a region in which temperatures again increase
with height. This temperature increase is caused by the absorption of energetic
ultraviolet and X-Ray radiation from the sun.
The region of
the atmosphere above about 80 km is also caused the "ionosphere",
since the energetic solar radiation knocks electrons off molecules and atoms,
turning them into "ions" with
a positive charge. The temperature of the thermosphere varies between night and
day and between the seasons, as do the numbers of ions and electrons which are
present. The ionosphere reflects and absorbs radio waves, allowing us to
receive shortwave radio broadcasts in New Zealand from other parts of the
world.
The Exosphere
The region above
about 500 km is called the exosphere. It contains mainly oxygen and hydrogen
atoms, but there are so few of them that they rarely collide - they follow "ballistic" trajectories under
the influence of gravity, and some of them escape right out into space.
The
Magnetosphere
The earth
behaves like a huge magnet. It traps electrons (negative charge) and protons
(positive), concentrating them in two bands about 3,000 and 16,000 km above the
globe - the Van Allen "radiation" belts. This outer region
surrounding the earth, where charged particles
spiral along the magnetic field lines, is called the magnetosphere.
Tuesday 25 October 2016
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