The HOPES Brain Tutorial (Non-Flash Version) Part 2
A guided tour of the human brain and its parts.
Central Nervous System
The brain is a part of the central nervous system (CNS). It receives information from other parts of the body via the spinal cord and the peripheral nervous system and uses this information to control the body.
Brain Cells
The brain is made up of two types of cells: neurons and glial cells. Neurons are nerve cells. They typically consist of dendrites that receive information, a cell body, and an axon that is used to transmit information throughout the nervous system. Glial cells have multiple functions, which include structurally supporting neurons, repairing the CNS, and regulating the biochemical balance of the brain. The blood-brain barrier is composed of astrocytes, a specific type of glial cell. This barrier prevents many substances in the blood from entering the brain.
Directions
The top of the brain is called the superior side, and the bottom is called the inferior side. Structures near the center are referred to as medial, and farther away from the center are referred to as lateral. The term anterior means ‘in front,’ while posterior means ‘behind.’
Protection
The brain is surrounded and protected by the rigid, bony skull and three membranes, or meninges. The tough, fibrous outer membrane is the dura mater. The intermediate membrane, named the arachnoid, is thin and weblike. The pia mater is the innermost covering and is the most delicate. It is molded to the shape of the brain. The cerebrospinal fluid (CSF) surrounds the brain and spinal cord and flows through open chambers in the brain, known as ventricles, and out an opening to the spinal cord. The brain actually floats in the shock-absorbing CSF, and is thus protected from trauma. The CSF also brings nutrients to the brain and removes wastes.
Last Modified: 4-29-04
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The brain is a part of the central nervous system (CNS). It receives information from other parts of the body via the spinal cord and the peripheral nervous system and uses this information to control the body.
The brain is made up of two types of cells: neurons and glial cells. Neurons are nerve cells. They typically consist of dendrites that receive information, a cell body, and an axon that is used to transmit information throughout the nervous system. Glial cells have multiple functions, which include structurally supporting neurons, repairing the CNS, and regulating the biochemical balance of the brain. The blood-brain barrier is composed of astrocytes, a specific type of glial cell. This barrier prevents many substances in the blood from entering the brain.
The top of the brain is called the superior side, and the bottom is called the inferior side. Structures near the center are referred to as medial, and farther away from the center are referred to as lateral. The term anterior means ‘in front,’ while posterior means ‘behind.’
The brain is surrounded and protected by the rigid, bony skull and three membranes, or meninges. The tough, fibrous outer membrane is the dura mater. The intermediate membrane, named the arachnoid, is thin and weblike. The pia mater is the innermost covering and is the most delicate. It is molded to the shape of the brain. The cerebrospinal fluid (CSF) surrounds the brain and spinal cord and flows through open chambers in the brain, known as ventricles, and out an opening to the spinal cord. The brain actually floats in the shock-absorbing CSF, and is thus protected from trauma. The CSF also brings nutrients to the brain and removes wastes.
