The Human Brain Function

3 Pages 801 Words

The Human Brain
Structure and functions

The brain is the control center of the body. Its like a telephone operator who answers
incoming calls and directs them to where they need to go. So think of the brain as an operator by
sending messages from all over the body to their proper destination. The brain is one of the largest and most important organs of the human body. Weighing in at about three pounds, this organ has a wide
range of responsibilities. From coordinating our movement to managing our emotions the brain does it
all.
The human brain is made up of billions of nerve cells, called neurons that share
information with one another through a collection of biological and chemical signals. Each neuron is
made up of a cell body, an axon, and many dendrites, all surrounded by a cell membrane. The nucleus,
which contains genes composed of deoxyribonucleic acid (DNA), controls the cell's activities. The
axon extends from the cell body and transmits messages to other neurons, sometimes over very long
distances. Dendrites, which also branch out from the cell body, receive messages from the axons and
specialized sense organs. Axons and dendrites collectively are called neurites. The body contains a
numerous amount of glial cells (such as astrocites), which surround, support, and nourish neurons.
Neurons communicate with each other as well as sense organs by producing and releasing special chemicals called neurotransmitters. As a neuron receives messages from surrounding cells, an electrical charge, called a nerve impulse, builds up within the cell. This charge travels down the axon
until it reaches the end. Once it has reached the end, it triggers the release of the neurotransmitters that
move from the axon across gaps called synapses. Scientists estimate that the typical neuron has up to
15,000 synapses. The neurotransmitters bind to specific receptor sites on the receiving end of dendrites or cell...