The BrainBy Ashia Lewis 7th Grade

August 16, 2011

Any man who reads too much and uses his own brain too little falls into lazy habits of thinking. -Albert Einstein

The human brain is the center of the human nervous system.

The central nervous system (CNS) is made of the brain and the spinal cord and the peripheral nervous system (PNS) is made of nerves.

The brain is made of three main parts: the forebrain, midbrain, and hindbrain.

The forebrain consists of the cerebrum, thalamus, and hypothalamus (part of the limbic system).

The midbrain consists of the tectum and tegmentum. The hindbrain is made of the cerebellum, pons and medulla. The midbrain, pons, and medulla are referred to together as the brainstem.

Most of the brain’s weight comes from theCerebral cortex, a bundled layer of neuraltissue which covers the forebrain.

The Brain

The cerebral cortex is divided into four sections, called "lobes": the frontal lobe, parietal lobe, occipital lobe, and temporal lobe.

Your frontal lobe controlsreasoning, planning, parts of speech, movement, emotions, and problem solving Your temporal lobe controlsperception and recognition of auditory stimuli, memory, and speech Your parietal lobe controlsmovement, orientation, recognition, perception of stimuli Your occipital lobe controlsvisual processing

A deep furrow divides the cerebrum into two halves, known as the left and right hemispheres.

The two hemispheres look mostly symmetrical yet it has been shown that each side functions slightly different than the other.

Sometimes the right hemisphere is associated with creativity and the left hemispheres is associated with logic abilities.

The corpus callosum is a bundle of axons which connects these two hemispheres.

Hemispheres

Nerve cells make up the gray surface of the cerebrum which is a little thicker than your thumb.

White nerve fibers underneath carry signals between the nerve cells and other parts of the brain and body.

The nucleus is the controller of this cell, and is guarded by neuron (or cell body).

Nerve Cells

The cerebellum, or "little brain", is similar to the cerebrum in that it has two hemispheres and has a highly folded surface or cortex.

This structure is associated with regulation and coordination of movement, posture, and balance.

Cerebellum

Limbic System

The limbic system, often referred to as the "emotional brain", is found buried within the cerebrum.

This system contains:ThalamusHypothalamusAmygdalaHippocampus

The thalamus is a large mass of gray matter that lies deep inside of the forebrain.

It covers sensory and motor functions.

Almost all sensory information enters this structure where neurons send that information to the overlying cortex.

Axons from every sensory system (except olfaction) synapse here as the last relay site before the information reaches the cerebral cortex.

The hypothalamus is part of the diencephalon, ventral to the thalamus.

It is involved with emotion, thirst, hunger, circadian rhythms, and control of the autonomic nervous system(reflexes).

The amygdala is a part of the telencephalon, which is located inside of temporal lobe.

It is involved with memory, emotion, and fear.

The amygdala is both large and just beneath the surface of the front, medial part of the temporal lobe where it causes the bulge on the surface called the incus.

This is a component of the limbic system.

The Hippocampus portion of the cerebral hemispheres in basal medial part of the temporal lobe.

This part of the brain is important for learning and memory . . . for turning short term memory to more permanent memory, and for recalling spatial relationships in the world about us.

Brain StemUnderneath the

limbic system is the brain stem.

It is responsible for vital life functions such as breathing, heartbeat, and blood pressure.

Scientists say that is the most simple part of the brain.

It is made of the midbrain, pons, and medulla.

The midbrain includes the tectum and tegmentum.

It is involved in functions such as vision, hearing, eye movement, and body movement.

The anterior part has the cerebral peduncle, which is a huge bundle of axons traveling from the cerebral cortex through the brain stem and these fibers (along with other structures) are important for voluntary motor function.

The pons are apart mesencephalon in the hindbrain.

It is involved in motor control and sensory analysis

It has parts that are important for the level of consciousness and for sleep.

Some structures within the pons are linked to the cerebellum, thus are involved in movement and posture.

The Medulla Oblongata is the caudal-most part of the brain stem, between the pons and spinal cord.

It is responsible for maintaining vital body functions, such as breathing and heart rate .

THE END

Toleration is the greatest gift of the mind; it requires the same effort of the brain that it takes to balance oneself on a bicycle. -Helen Keller