The structure and importance of the nervous system
The human nervous system
The nervous system is a communication and controlling body system , It consists of the brain , the spinal cord and the nerves , and it is the most important system inside your body .
The nervous system controls and regulates all the vital operations of the body , Because it receives the information from the environment and from the body , then it interprets this information and makes the body respond to it .
The nervous system is responsible for knowing if the things are hot or cold , sweet or bitter , rough or smooth , The nervous system adjusts the responses that require the emotions , so it makes you sad or happy , angry or calm .
The nervous system oversees and regulates the multiple functions performed by the human body such as moving , feeding , digestion , breathing , thinking and others .
The structure of the nervous system
The nervous system consists of two major systems which are the central nervous system and the peripheral nervous system .
The building unit of the nervous system is the nerve cell that is called the neuron , and it consists of two main parts which are the cell body and the axon , The cell body contains a nucleus , the cytoplasm and the plasma membrane .
There are some branches extending from the neuron’s body called the dendrites , The dendrites are connected to the neighbouring neurons to form the synapse ( the synaptic areas ) .
The axon is a cylindrical axis covered with a fatty layer called myelin sheath , and it ends with nerve endings called the axon terminals , The axon terminals are connected to the muscles or form a synapse with other neurons .
The nerve cell’s axons are grouped together forming the nerve fibre . and the nerve fibres are grouped together forming the nerve .