The Parts of the Brain

Brain Basics: Know Your Brain | National Institute of Neurological Disorders and Stroke

The Parts of the Brain

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Introduction
The Architecture of the Brain
The Geography of Thought
The Cerebral Cortex
The Inner Brain
Making Connections
Some Key Neurotransmitters at Work
Neurological Disorders
The National Institute of Neurological Disorders and Stroke

Introduction

The brain is the most complex part of the human body. This three-pound organ is the seat of intelligence, interpreter of the senses, initiator of body movement, and controller of behavior. Lying in its bony shell and washed by protective fluid, the brain is the source of all the qualities that define our humanity. The brain is the crown jewel of the human body.

For centuries, scientists and philosophers have been fascinated by the brain, but until recently they viewed the brain as nearly incomprehensible. Now, however, the brain is beginning to relinquish its secrets.

Scientists have learned more about the brain in the last 10 years than in all previous centuries because of the accelerating pace of research in neurological and behavioral science and the development of new research techniques. As a result, Congress named the 1990s the Decade of the Brain.

At the forefront of research on the brain and other elements of the nervous system is the National Institute of Neurological Disorders and Stroke (NINDS), which conducts and supports scientific studies in the United States and around the world.

This fact sheet is a basic introduction to the human brain. It may help you understand how the healthy brain works, how to keep it healthy, and what happens when the brain is diseased or dysfunctional.

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The Architecture of the Brain

The brain is a committee of experts. All the parts of the brain work together, but each part has its own special properties. The brain can be divided into three basic units: the forebrain, the midbrain, and the hindbrain.

The hindbrain includes the upper part of the spinal cord, the brain stem, and a wrinkled ball of tissue called the cerebellum (1). The hindbrain controls the body’s vital functions such as respiration and heart rate. The cerebellum coordinates movement and is involved in learned rote movements.

When you play the piano or hit a tennis ball you are activating the cerebellum. The uppermost part of the brainstem is the midbrain, which controls some reflex actions and is part of the circuit involved in the control of eye movements and other voluntary movements.

The forebrain is the largest and most highly developed part of the human brain: it consists primarily of the cerebrum (2) and the structures hidden beneath it (see «The Inner Brain»).

When people see pictures of the brain it is usually the cerebrum that they notice. The cerebrum sits at the topmost part of the brain and is the source of intellectual activities. It holds your memories, allows you to plan, enables you to imagine and think. It allows you to recognize friends, read books, and play games.

The cerebrum is split into two halves (hemispheres) by a deep fissure. Despite the split, the two cerebral hemispheres communicate with each other through a thick tract of nerve fibers that lies at the base of this fissure.

Although the two hemispheres seem to be mirror images of each other, they are different.

For instance, the ability to form words seems to lie primarily in the left hemisphere, while the right hemisphere seems to control many abstract reasoning skills.

For some as-yet-unknown reason, nearly all of the signals from the brain to the body and vice-versa cross over on their way to and from the brain.

This means that the right cerebral hemisphere primarily controls the left side of the body and the left hemisphere primarily controls the right side. When one side of the brain is damaged, the opposite side of the body is affected.

For example, a stroke in the right hemisphere of the brain can leave the left arm and leg paralyzed.

            The Forebrain                              The Midbrain                             The Hindbrain

The Geography of Thought

Each cerebral hemisphere can be divided into sections, or lobes, each of which specializes in different functions.

To understand each lobe and its specialty we will take a tour of the cerebral hemispheres, starting with the two frontal lobes (3), which lie directly behind the forehead.

When you plan a schedule, imagine the future, or use reasoned arguments, these two lobes do much of the work.

One of the ways the frontal lobes seem to do these things is by acting as short-term storage sites, allowing one idea to be kept in mind while other ideas are considered. In the rearmost portion of each frontal lobe is a motor area (4), which helps control voluntary movement. A nearby place on the left frontal lobe called Broca’s area (5) allows thoughts to be transformed into words.

When you enjoy a good meal—the taste, aroma, and texture of the food—two sections behind the frontal lobes called the parietal lobes (6) are at work.

The forward parts of these lobes, just behind the motor areas, are the primary sensory areas (7). These areas receive information about temperature, taste, touch, and movement from the rest of the body.

Reading and arithmetic are also functions in the repertoire of each parietal lobe.

As you look at the words and pictures on this page, two areas at the back of the brain are at work. These lobes, called the occipital lobes (8), process images from the eyes and link that information with images stored in memory. Damage to the occipital lobes can cause blindness.

The last lobes on our tour of the cerebral hemispheres are the temporal lobes (9), which lie in front of the visual areas and nest under the parietal and frontal lobes. Whether you appreciate symphonies or rock music, your brain responds through the activity of these lobes.

At the top of each temporal lobe is an area responsible for receiving information from the ears. The underside of each temporal lobe plays a crucial role in forming and retrieving memories, including those associated with music.

Other parts of this lobe seem to integrate memories and sensations of taste, sound, sight, and touch.

The Cerebral Cortex

Coating the surface of the cerebrum and the cerebellum is a vital layer of tissue the thickness of a stack of two or three dimes. It is called the cortex, from the Latin word for bark. Most of the actual information processing in the brain takes place in the cerebral cortex.

When people talk about «gray matter» in the brain they are talking about this thin rind. The cortex is gray because nerves in this area lack the insulation that makes most other parts of the brain appear to be white.

The folds in the brain add to its surface area and therefore increase the amount of gray matter and the quantity of information that can be processed.

The Inner Brain

Deep within the brain, hidden from view, lie structures that are the gatekeepers between the spinal cord and the cerebral hemispheres.

These structures not only determine our emotional state, they also modify our perceptions and responses depending on that state, and allow us to initiate movements that you make without thinking about them.

the lobes in the cerebral hemispheres, the structures described below come in pairs: each is duplicated in the opposite half of the brain.

The hypothalamus (10), about the size of a pearl, directs a multitude of important functions. It wakes you up in the morning, and gets the adrenaline flowing during a test or job interview.

The hypothalamus is also an important emotional center, controlling the molecules that make you feel exhilarated, angry, or unhappy.

Near the hypothalamus lies the thalamus (11), a major clearinghouse for information going to and from the spinal cord and the cerebrum.

An arching tract of nerve cells leads from the hypothalamus and the thalamus to the hippocampus (12). This tiny nub acts as a memory indexer—sending memories out to the appropriate part of the cerebral hemisphere for long-term storage and retrieving them when necessary.

The basal ganglia (not shown) are clusters of nerve cells surrounding the thalamus. They are responsible for initiating and integrating movements.

Parkinson’s disease, which results in tremors, rigidity, and a stiff, shuffling walk, is a disease of nerve cells that lead into the basal ganglia.

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Making Connections

The brain and the rest of the nervous system are composed of many different types of cells, but the primary functional unit is a cell called the neuron. All sensations, movements, thoughts, memories, and feelings are the result of signals that pass through neurons. Neurons consist of three parts.

The cell body (13) contains the nucleus, where most of the molecules that the neuron needs to survive and function are manufactured. Dendrites (14) extend out from the cell body the branches of a tree and receive messages from other nerve cells.

Signals then pass from the dendrites through the cell body and may travel away from the cell body down an axon (15) to another neuron, a muscle cell, or cells in some other organ. The neuron is usually surrounded by many support cells.

Some types of cells wrap around the axon to form an insulating sheath (16). This sheath can include a fatty molecule called myelin, which provides insulation for the axon and helps nerve signals travel faster and farther.

Axons may be very short, such as those that carry signals from one cell in the cortex to another cell less than a hair’s width away. Or axons may be very long, such as those that carry messages from the brain all the way down the spinal cord.

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Scientists have learned a great deal about neurons by studying the synapse—the place where a signal passes from the neuron to another cell. When the signal reaches the end of the axon it stimulates the release of tiny sacs (17).

These sacs release chemicals known as neurotransmitters (18) into the synapse (19). The neurotransmitters cross the synapse and attach to receptors (20) on the neighboring cell. These receptors can change the properties of the receiving cell.

If the receiving cell is also a neuron, the signal can continue the transmission to the next cell.

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Some Key Neurotransmitters at Work

Neurotransmitters are chemicals that brain cells use to talk to each other. Some neurotransmitters make cells more active (called excitatory) while others block or dampen a cell's activity (called inhibitory).

Acetylcholine is an excitatory neurotransmitter because it generally makes cells more excitable. It governs muscle contractions and causes glands to secrete hormones. Alzheimer’s disease, which initially affects memory formation, is associated with a shortage of acetylcholine.

Glutamate is a major excitatory neurotransmitter. Too much glutamate can kill or damage neurons and has been linked to disorders including Parkinson's disease, stroke, seizures, and increased sensitivity to pain.

GABA (gamma-aminobutyric acid) is an inhibitory neurotransmitter that helps control muscle activity and is an important part of the visual system. Drugs that increase GABA levels in the brain are used to treat epileptic seizures and tremors in patients with Huntington’s disease.

Serotonin is a neurotransmitter that constricts blood vessels and brings on sleep. It is also involved in temperature regulation. Low levels of serotonin may cause sleep problems and depression, while too much serotonin can lead to seizures.

Dopamine is an inhibitory neurotransmitter involved in mood and the control of complex movements. The loss of dopamine activity in some portions of the brain leads to the muscular rigidity of Parkinson’s disease. Many medications used to treat behavioral disorders work by modifying the action of dopamine in the brain.

Neurological Disorders

The brain is one of the hardest working organs in the body. When the brain is healthy it functions quickly and automatically. But when problems occur, the results can be devastating. Some 100 million Americans suffer from devastating brain disorders at some point in their lives.

 The NINDS supports research on more than 600 neurological diseases.

Some of the major types of disorders include: neurogenetic diseases (such as Huntington’s disease and muscular dystrophy), developmental disorders (such as cerebral palsy), degenerative diseases of adult life (such as Parkinson’s disease and Alzheimer’s disease), metabolic diseases (such as Gaucher’s disease), cerebrovascular diseases (such as stroke and vascular dementia), trauma (such as spinal cord and head injury), convulsive disorders (such as epilepsy), infectious diseases (such as AIDS dementia), and brain tumors. Knowing more about the brain can lead to the development of new treatments for diseases and disorders of the nervous system and improve many areas of human health.

The National Institute of Neurological Disorders and Stroke

Since its creation by Congress in 1950, the NINDS has grown to become the leading supporter of neurological research in the United States. Most research funded by the NINDS is conducted by scientists in public and private institutions such as universities, medical schools, and hospitals.

Government scientists also conduct a wide array of neurological research in the more than 20 laboratories and branches of the NINDS itself.

This research ranges from studies on the structure and function of single brain cells to tests of new diagnostic tools and treatments for those with neurological disorders.

For information on other neurological disorders or research programs funded by the National Institute of Neurological Disorders and Stroke, contact the Institute's Brain Resources and Information Network (BRAIN) at:

BRAINP.O. Box 5801Bethesda, MD 20824(800) 352-9424

www.ninds.nih.gov 

Источник: https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Know-Your-Brain

Brain Anatomy and How the Brain Works

The Parts of the Brain

The brain is a complex organ that controls thought, memory, emotion, touch, motor skills, vision, breathing, temperature, hunger and every process that regulates our body. Together, the brain and spinal cord that extends from it make up the central nervous system, or CNS.

What is the brain made of?

Weighing about 3 pounds in the average adult, the brain is about 60% fat. The remaining 40% is a combination of water, protein, carbohydrates and salts. The brain itself is a not a muscle. It contains blood vessels and nerves, including neurons and glial cells.

What is the gray matter and white matter?

Gray and white matter are two different regions of the central nervous system. In the brain, gray matter refers to the darker, outer portion, while white matter describes the lighter, inner section underneath. In the spinal cord, this order is reversed: The white matter is on the outside, and the gray matter sits within.

Gray matter is primarily composed of neuron somas (the round central cell bodies), and white matter is mostly made of axons (the long stems that connects neurons together) wrapped in myelin (a protective coating). The different composition of neuron parts is why the two appear as separate shades on certain scans.

Each region serves a different role. Gray matter is primarily responsible for processing and interpreting information, while white matter transmits that information to other parts of the nervous system.

How does the brain work?

The brain sends and receives chemical and electrical signals throughout the body. Different signals control different processes, and your brain interprets each. Some make you feel tired, for example, while others make you feel pain.

Some messages are kept within the brain, while others are relayed through the spine and across the body’s vast network of nerves to distant extremities. To do this, the central nervous system relies on billions of neurons (nerve cells).

Main Parts of the Brain and Their Functions

At a high level, the brain can be divided into the cerebrum, brainstem and cerebellum.

Cerebrum

The cerebrum (front of brain) comprises gray matter (the cerebral cortex) and white matter at its center.

The largest part of the brain, the cerebrum initiates and coordinates movement and regulates temperature.

Other areas of the cerebrum enable speech, judgment, thinking and reasoning, problem-solving, emotions and learning. Other functions relate to vision, hearing, touch and other senses.

Cerebral Cortex

Cortex is Latin for “bark,” and describes the outer gray matter covering of the cerebrum. The cortex has a large surface area due to its folds, and comprises about half of the brain’s weight.

The cerebral cortex is divided into two halves, or hemispheres. It is covered with ridges (gyri) and folds (sulci). The two halves join at a large, deep sulcus (the interhemispheric fissure, AKA the medial longitudinal fissure) that runs from the front of the head to the back.

The right hemisphere controls the left side of the body, and the left half controls the right side of the body. The two halves communicate with one another through a large, C-shaped structure of white matter and nerve pathways called the corpus callosum.

The corpus callosum is in the center of the cerebrum.

Brainstem

The brainstem (middle of brain) connects the cerebrum with the spinal cord. The brainstem includes the midbrain, the pons and the medulla.

  • Midbrain. The midbrain (or mesencephalon) is a very complex structure with a range of different neuron clusters (nuclei and colliculi), neural pathways and other structures. These features facilitate various functions, from hearing and movement to calculating responses and environmental changes. The midbrain also contains the substantia nigra, an area affected by Parkinson’s disease that is rich in dopamine neurons and part of the basal ganglia, which enables movement and coordination.
  • Pons. The pons is the origin for four of the 12 cranial nerves, which enable a range of activities such as tear production, chewing, blinking, focusing vision, balance, hearing and facial expression. Named for the Latin word for “bridge,” the pons is the connection between the midbrain and the medulla.
  • Medulla. At the bottom of the brainstem, the medulla is where the brain meets the spinal cord. The medulla is essential to survival. Functions of the medulla regulate many bodily activities, including heart rhythm, breathing, blood flow, and oxygen and carbon dioxide levels. The medulla produces reflexive activities such as sneezing, vomiting, coughing and swallowing.

The spinal cord extends from the bottom of the medulla and through a large opening in the bottom of the skull. Supported by the vertebrae, the spinal cord carries messages to and from the brain and the rest of the body.

Cerebellum

The cerebellum (“little brain”) is a fist-sized portion of the brain located at the back of the head, below the temporal and occipital lobes and above the brainstem. the cerebral cortex, it has two hemispheres.

The outer portion contains neurons, and the inner area communicates with the cerebral cortex. Its function is to coordinate voluntary muscle movements and to maintain posture, balance and equilibrium.

New studies are exploring the cerebellum’s roles in thought, emotions and social behavior, as well as its possible involvement in addiction, autism and schizophrenia.

Brain Coverings: Meninges

Three layers of protective covering called meninges surround the brain and the spinal cord.

  • The outermost layer, the dura mater, is thick and tough. It includes two layers: The periosteal layer of the dura mater lines the inner dome of the skull (cranium) and the meningeal layer is below that. Spaces between the layers allow for the passage of veins and arteries that supply blood flow to the brain.
  • The arachnoid mater is a thin, web layer of connective tissue that does not contain nerves or blood vessels. Below the arachnoid mater is the cerebrospinal fluid, or CSF. This fluid cushions the entire central nervous system (brain and spinal cord) and continually circulates around these structures to remove impurities.
  • The pia mater is a thin membrane that hugs the surface of the brain and follows its contours. The pia mater is rich with veins and arteries.

Lobes of the Brain and What They Control

Each brain hemisphere (parts of the cerebrum) has four sections, called lobes: frontal, parietal, temporal and occipital. Each lobe controls specific functions.

  • Frontal lobe. The largest lobe of the brain, located in the front of the head, the frontal lobe is involved in personality characteristics, decision-making and movement. Recognition of smell usually involves parts of the frontal lobe. The frontal lobe contains Broca’s area, which is associated with speech ability.
  • Parietal lobe. The middle part of the brain, the parietal lobe helps a person identify objects and understand spatial relationships (where one’s body is compared with objects around the person). The parietal lobe is also involved in interpreting pain and touch in the body. The parietal lobe houses Wernicke’s area, which helps the brain understand spoken language.
  • Occipital lobe. The occipital lobe is the back part of the brain that is involved with vision.
  • Temporal lobe. The sides of the brain, temporal lobes are involved in short-term memory, speech, musical rhythm and some degree of smell recognition.

Pituitary Gland

Sometimes called the “master gland,” the pituitary gland is a pea-sized structure found deep in the brain behind the bridge of the nose. The pituitary gland governs the function of other glands in the body, regulating the flow of hormones from the thyroid, adrenals, ovaries and testicles. It receives chemical signals from the hypothalamus through its stalk and blood supply.

Hypothalamus

The hypothalamus is located above the pituitary gland and sends it chemical messages that control its function. It regulates body temperature, synchronizes sleep patterns, controls hunger and thirst and also plays a role in some aspects of memory and emotion.

Amygdala

Small, almond-shaped structures, an amygdala is located under each half (hemisphere) of the brain. Included in the limbic system, the amygdalae regulate emotion and memory and are associated with the brain’s reward system, stress, and the “fight or flight” response when someone perceives a threat.

Hippocampus

A curved seahorse-shaped organ on the underside of each temporal lobe, the hippocampus is part of a larger structure called the hippocampal formation. It supports memory, learning, navigation and perception of space. It receives information from the cerebral cortex and may play a role in Alzheimer’s disease.

Pineal Gland

The pineal gland is located deep in the brain and attached by a stalk to the top of the third ventricle. The pineal gland responds to light and dark and secretes melatonin, which regulates circadian rhythms and the sleep-wake cycle.

Ventricles and Cerebrospinal Fluid

Deep in the brain are four open areas with passageways between them. They also open into the central spinal canal and the area beneath arachnoid layer of the meninges.

The ventricles manufacture cerebrospinal fluid, or CSF, a watery fluid that circulates in and around the ventricles and the spinal cord, and between the meninges. CSF surrounds and cushions the spinal cord and brain, washes out waste and impurities, and delivers nutrients.

Blood Supply to the Brain

Two sets of blood vessels supply blood and oxygen to the brain: the vertebral arteries and the carotid arteries.

The external carotid arteries extend up the sides of your neck, and are where you can feel your pulse when you touch the area with your fingertips. The internal carotid arteries branch into the skull and circulate blood to the front part of the brain.

The vertebral arteries follow the spinal column into the skull, where they join together at the brainstem and form the basilar artery, which supplies blood to the rear portions of the brain.

The circle of Willis, a loop of blood vessels near the bottom of the brain that connects major arteries, circulates blood from the front of the brain to the back and helps the arterial systems communicate with one another.

Cranial Nerves

Inside the cranium (the dome of the skull), there are 12 nerves, called cranial nerves:

  • Cranial nerve 1: The first is the olfactory nerve, which allows for your sense of smell.
  • Cranial nerve 2: The optic nerve governs eyesight.
  • Cranial nerve 3: The oculomotor nerve controls pupil response and other motions of the eye, and branches out from the area in the brainstem where the midbrain meets the pons.
  • Cranial nerve 4: The trochlear nerve controls muscles in the eye. It emerges from the back of the midbrain part of the brainstem.
  • Cranial nerve 5: The trigeminal nerve is the largest and most complex of the cranial nerves, with both sensory and motor function. It originates from the pons and conveys sensation from the scalp, teeth, jaw, sinuses, parts of the mouth and face to the brain, allows the function of chewing muscles, and much more.
  • Cranial nerve 6: The abducens nerve innervates some of the muscles in the eye.
  • Cranial nerve 7: The facial nerve supports face movement, taste, glandular and other functions.
  • Cranial nerve 8: The vestibulocochlear nerve facilitates balance and hearing.
  • Cranial nerve 9: The glossopharyngeal nerve allows taste, ear and throat movement, and has many more functions.
  • Cranial nerve 10: The vagus nerve allows sensation around the ear and the digestive system and controls motor activity in the heart, throat and digestive system.
  • Cranial nerve 11: The accessory nerve innervates specific muscles in the head, neck and shoulder.
  • Cranial nerve 12: The hypoglossal nerve supplies motor activity to the tongue.

The first two nerves originate in the cerebrum, and the remaining 10 cranial nerves emerge from the brainstem, which has three parts: the midbrain, the pons and the medulla.

Источник: https://www.hopkinsmedicine.org/health/conditions-and-diseases/anatomy-of-the-brain

Brain Structure And Function | Brain Injury | British Columbia

The Parts of the Brain

The brain structure is composed of three main parts: the forebrain, midbrain and hindbrain, each with multiple parts.

Forebrain

The Cerebrum: Also known as the cerebral cortex, the cerebrum is the largest part of the human brain, and it is associated with higher brain function such as thought and action. Nerve cells make up the gray surface, which is a little thicker than our thumb.

White nerve fibers beneath the surface carry signals between nerve cells in other parts of the brain and body. Its wrinkled surface increases the surface area, and is a six-layered structure found in mammals, called the neocortex. It is divided into four sections, called “lobes”.

They are; the frontal lobe, the parietal lobe, the occipital lobe and the temporal lobe.

Functions Of The Lobes:

Frontal Lobe – The frontal lobe lies just beneath our forehead and is associated with our brain’s ability to reason, organize, plan, speak, move, make facial expressions, serial task, problem solve, control inhibition, spontaneity, initiate and self-regulate behaviors, pay attention, remember and control emotions.

Parietal Lobe – The parietal lobe is located at the upper rear of our brain, and controls our complex behaviors, including senses such as vision, touch, body awareness and spatial orientation.

It plays important roles in integrating sensory information from various parts of our body, knowledge of numbers and their relations, and in the manipulation of objects.

Portions are involved with our visuospatial processing, language comprehension, the ability to construct, body positioning and movement, neglect/inattention, left-right differentiation and self-awareness/insight.

Occipital Lobe – The occipital lobe is located at the back of our brain, and is associated with our visual processing, such as visual recognition, visual attention, spatial analysis (moving in a 3-D world) and visual perception of body language; such as postures, expressions and gestures.

Temporal Lobe – The temporal lobe is located near our ears, and is associated with processing our perception and recognition of auditory stimuli (including our ability to focus on one sound among many, listening to one voice among many at a party), comprehending spoken language, verbal memory, visual memory and language production (including fluency and word-finding), general knowledge and autobiographical memories.

A deep furrow divides the cerebrum into two halves, known as the left and right hemispheres. And, while the two hemispheres look almost symmetrical, each side seems to function differently. The right hemisphere is considered our creative side, and the left hemisphere is considered our logical side. A bundle of axons, called the corpus callosum, connects the two hemispheres.

Midbrain

The midbrain is located below the cerebral cortex, and above the hindbrain placing it near the center of the brain. It is comprised of the tectum, tegmentum, cerebral aqueduct, cerebral peduncles and several nuclei and fasciculi. The primary role of the midbrain is to act as a sort of relay station for our visual and auditory systems.

Portions of the midbrain called the red nucleus and the substantia nigra are involved in the control of body movement, and contain a large number of dopamine-producing neurons. The degeneration of neurons in the substantia nigra is associated with Parkinson’s disease.

The midbrain is the smallest region of the brain, and is located most centrally within the cranial cavity.

Limbic System – the limbic system is often referred to as our “emotional brain”, or ‘childish brain’. It is found buried within the cerebrum and contains the thalamus, hypothalamus, amygdala and hippocampus.

Thalamus – the primary role of the thalamus is to relay sensory information from other parts of the brain to the cerebral cortex

Hypothalamus – the primary role of the hypothalamus is to regulate various functions of the pituitary gland and endocrine activity, as well as somatic functions e.g.body temperature, sleep, appetite.

Amygdala – the primary role of the amygdala is to be a critical processor for the senses. Connected to the hippocampus, it plays a role in emotionally laden memories and contains a huge number of opiate receptor sites that are implicated in rage, fear and sexual feelings.

Hippocampus – the primary role of the hippocampus is memory forming, organizing and storing information. It is particularly important in forming new memories, and connecting emotions and senses, such as smell and sound, to memories.

Pituitary Gland – the primary role of the pituitary gland is an important link between the nervous system and the endocrine system. It releases many hormones which affect growth, metabolism, sexual development and the reproduction system. It is connected to the hypothalamus and is about the size of a pea. It is located in the center of the skull, just behind the bridge of the nose.

Hindbrain

The Cerebellum – The cerebellum, or “little brain”, is similar to the cerebrum with its two hemispheres and highly folded surface. It is associated with regulation and coordination of movement, posture, balance and cardiac, respiratory and vasomotor centers.

Brain Stem – The brain stem is located beneath the limbic system. It is responsible for vital life functions such as breathing, heartbeat, and blood pressure. The brain stem is made of the midbrain, pons, and medulla.

Pons – The primary role of the pons is to serve as a bridge between various parts of the nervous system, including the cerebellum and cerebrum.

Many important nerves that originate in the pons, such as the trigeminal nerve, responsible for feeling in the face, as well as controlling the muscles that are responsible for biting, chewing, and swallowing.

It also contains the abducens nerve, which allows us to look from side to side and the vestibularcochlear nerve, which allows to hear.

As part of the brainstem, a section of the lower pons stimulates and controls the intensity of breathing, while a section of the upper pons decreases the depth and frequency of breaths. The pons is also associated with the control of sleep cycles, and controls respiration and reflexes. It is located above the medulla, below the midbrain, and just in front of the cerebellum.

Medulla – The primary role of the medulla is regulating our involuntary life sustaining functions such as breathing, swallowing and heart rate. As part of the brain stem, it also helps transfer neural messages to and from the brain and spinal cord. It is located at the junction of the spinal cord and brain.

Источник: https://www.nbia.ca/brain-structure-function/

Your Brain & Nervous System

The Parts of the Brain

How do you remember the way to your friend's house? Why do your eyes blink without you ever thinking about it? Where do dreams come from? Your brain is in charge of these things and a lot more.

In fact, your brain is the boss of your body. It runs the show and controls just about everything you do, even when you're asleep. Not bad for something that looks a big gray wrinkly sponge.

Your brain has many different parts that work together. We're going to talk about these five parts, which are key players on the brain team:

  1. cerebrum (say: suh-REE-brum)
  2. cerebellum (say: sair-uh-BELL-um)
  3. brain stem
  4. pituitary (say: puh-TOO-uh-ter-ee) gland
  5. hypothalamus (say: hy-po-THAL-uh-mus)

The Biggest Part: the Cerebrum

The biggest part of the brain is the cerebrum. The cerebrum is the thinking part of the brain and it controls your voluntary muscles — the ones that move when you want them to. So you need your cerebrum to dance or kick a soccer ball.

You need your cerebrum to solve math problems, figure out a video game, and draw a picture.

Your memory lives in the cerebrum — both short-term memory (what you ate for dinner last night) and long-term memory (the name of that roller-coaster you rode on two summers ago).

The cerebrum also helps you reason, when you figure out that you'd better do your homework now because your mom is taking you to a movie later.

The cerebrum has two halves, with one on either side of the head. Scientists think that the right half helps you think about abstract things music, colors, and shapes.

The left half is said to be more analytical, helping you with math, logic, and speech.

Scientists do know for sure that the right half of the cerebrum controls the left side of your body, and the left half controls the right side.

The Cerebellum's Balancing Act

Next up is the cerebellum. The cerebellum is at the back of the brain, below the cerebrum. It's a lot smaller than the cerebrum. But it's a very important part of the brain. It controls balance, movement, and coordination (how your muscles work together).

Because of your cerebellum, you can stand upright, keep your balance, and move around. Think about a surfer riding the waves on his board. What does he need most to stay balanced? The best suroard? The coolest wetsuit? Nope — he needs his cerebellum!

Brain Stem Keeps You Breathing — and More

Another brain part that's small but mighty is the brain stem. The brain stem sits beneath the cerebrum and in front of the cerebellum. It connects the rest of the brain to the spinal cord, which runs down your neck and back. The brain stem is in charge of all the functions your body needs to stay alive, breathing air, digesting food, and circulating blood.

Part of the brain stem's job is to control your involuntary muscles — the ones that work automatically, without you even thinking about it.

There are involuntary muscles in the heart and stomach, and it's the brain stem that tells your heart to pump more blood when you're biking or your stomach to start digesting your lunch.

The brain stem also sorts through the millions of messages that the brain and the rest of the body send back and forth. Whew! It's a big job being the brain's secretary!

Pituitary Gland Controls Growth

The pituitary gland is very small — only about the size of a pea! Its job is to produce and release hormones into your body.

If your clothes from last year are too small, it's because your pituitary gland released special hormones that made you grow. This gland is a big player in puberty too.

This is the time when boys' and girls' bodies go through major changes as they slowly become men and women, all thanks to hormones released by the pituitary gland.

This little gland also plays a role with lots of other hormones, ones that control the amount of sugars and water in your body.

Hypothalamus Controls Temperature

The hypothalamus is your brain's inner thermostat (that little box on the wall that controls the heat in your house). The hypothalamus knows what temperature your body should be (about 98.6°F or 37°C).

If your body is too hot, the hypothalamus tells it to sweat. If you're too cold, the hypothalamus gets you shivering.

Both shivering and sweating are attempts to get your body's temperature back where it needs to be.

So the brain is boss, but it can't do it alone. It needs some nerves — actually a lot of them. And it needs the spinal cord, which is a long bundle of nerves inside your spinal column, the vertebrae that protect it. It's the spinal cord and nerves — known as the nervous system — that let messages flow back and forth between the brain and body.

If a spiky cactus falls off a shelf headed right for your best friend, your nerves and brain communicate so that you jump up and yell for your friend to get the way. If you're really good, maybe you're able to catch the plant before it hits your friend!

The nervous system is made up of millions and millions of neurons (say: NUR-onz), which are microscopic cells. Each neuron has tiny branches coming off it that let it connect to many other neurons.

When you learn things, the messages travel from one neuron to another, over and over. Eventually, the brain starts to create connections (or pathways) between the neurons, so things become easier and you can do them better and better.

Think back to the first time you rode a bike. Your brain had to think about pedaling, staying balanced, steering with the handlebars, watching the road, and maybe even hitting the brakes — all at once.

Hard work, right? But eventually, as you got more practice, the neurons sent messages back and forth until a pathway was created in your brain.

Now you can ride your bike without thinking about it because the neurons have successfully created a «bike riding» pathway.

Emotion Location

With all the other things it does, is it any surprise that the brain runs your emotions? Maybe you had fun on your birthday and you were really happy. Or your friend is sick and you feel sad. Or your little brother messed up your room, so you're really angry! Where do those feelings come from? Your brain, of course.

Your brain has a little bunch of cells on each side called the amygdala (say: uh-MIG-duh-luh). The word amygdala is Latin for almond, and that's what this area looks .

Scientists believe that the amygdala is responsible for emotion. It's normal to feel all different kinds of emotions, good and bad.

Sometimes you might feel a little sad, and other times you might feel scared, or silly, or glad.

Be Good to Your Brain

So what can you do for your brain? Plenty.

  • Eat healthy foods. They contain vitamins and minerals that are important for the nervous system.
  • Get a lot of playtime (exercise).
  • Wear a helmet when you ride your bike or play other sports that require head protection.
  • Don't drink alcohol, take drugs, or use tobacco.
  • Use your brain by doing challenging activities, such as puzzles, reading, playing music, making art, or anything else that gives your brain a workout!

Источник: https://kidshealth.org/en/kids/brain.html

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