The Human Brain and Nervous System

by Nyein Chan

The brain is the most fragile part of the body. If the heart stopped pumping blood, the brain would be the first organ to die. It consumes the most sugar in the body (when you’re not exercising). If your brain does not receive a sufficient supply of sugar, you will feel dizzy.

The brain has many parts and functions. The main parts of the brain are the cerebrum, cerebellum, and brain stem.

The cerebrum is divided into four sections: frontal lobe, temporal lobe, parietal lobe, and occipital lobe. Each section has it’s own function and sometimes more than one of the parts can have the same function. Here are the main functions that each part of the cerebrum control:


Frontal Lobe:

–       behavior and emotions

–       solving problems

–       inhibitions

–       judgment

–       movement of muscles

–       sense of smell

Occipital Lobe:

–       vision

Parietal Lobe:

–       sense of touch and appreciation of form through the sense of touch

–       sense of position, temperature, hunger, and thirst

–       some vision

Temporal Lobe:

–       memories of voices and sound

–       memories of visions

–       some speech

–       fear

–       sense of identity

The cerebellum is located at the back of your head underneath the cerebrum. It controls posture, balance, and some involuntary actions.

The brain stem is the center of involuntary actions and vital organs. It controls breathing, digestion, heart rate, blood pressure, and internal body temperature.

Brain cell are called neurons. A nerve is a long and thin piece of fiber that extends from a neuron. If a neuron is damaged, it can not be replaced. The fiber is so thin that it can not be seen without a microscope.

The spinal cord is a group of nerves that connects the brain and the nerves all over the body. The brain does not have its own nerve supply. So if your brain is damaged you can not feel it. The spinal cord is protected by the cervical, thoracic, and lumbar vertebrae. The white matter is located on the surface of the spinal cord.

neuronsspinal cord

The gray matter is located in the center of the spinal cord.

There are three types of neurons: unipolar, bipolar, and multipolar.

Unipolar Neuron:

A unipolar neuron has one pole and is most common in animals without a vertebrae. In the human body many of the sensory neurons are unipolar. The fiber  that extends from a unipolar neuron is the dendrite and axon.

Bipolar Neuron:

A bipolar neuron is something that is found in the special senses. These types of neurons have two extensions connected to the cell body. One pole of a bipolar neuron is the axon and the other pole dendrite.

Multipolar Neurons:

A multipolar neuron has three or more dendrites and one axon. Most motor neurons are multipolar neurons. The multipolar neurons are found in the spinal cord and brain.


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