The Nervous System

1. The Nervous System

2. CNS/PNS The nervous is made up of two sections of nerves. The central nervous system(CNS) and the Peripheral nervous system(PNS). The central nervous system is used to send signals to the muscles which affect the contractor muscles and the relaxer muscles, which enable movements like walking running and waiving.

3. Neurons The nervous system is made up of 2 cells. The cells are neurons and glial cells. Neurons can be distinguished in many different ways but the main reason is that they can communicate to other cells through synapses. This is a membrane to membrane junction that allows quick transfer of signals. Attached to the nerve are axons, which are protoplasmic protrusions that are able to extend farther out into the body and are able to carry out thousands of synaptic contacts. Axons travel through the body in bundles called nerves.

4. Glial Glial cells are non neuronal cells that provide support, nutrition, maintain homeostasis, form myelin, and participate in signal transmission in the nervous system. In the human brain it is estimated that the number of glia and equal to the number of neurons. Although this varies from the different parts of the brain. Some very important glial (oligoldendrocytes in the CNS and Schwann cells in the PNS)create a chemical known as myelin that wraps around the axis and also creates electrical insulation that helps transmit electrical signals even faster.

5. Function The brain sends signals through your body in 2 different ways. It can send it through hormones and electrical impulses. Neurons project there axons to different neurons and create synaptic connections. These signals can be more specific than chemical signals and they can contact specific cells. These signals can exceed 100metres/second. The main function of the nervous system is to control the body. Sensory receptors take in what is happening in the environment and the encode and send the information to the central nervous system. It then processes the information to create an appropriate response by sending either chemical or electrical signals which activate different muscles or glands.

6. Synapses Synapses are signals sent through the nervous system. It can be an electrical signal, which is sent directly from neuron to neuron. They can also be chemical signals which aren't as specific as electrical ones. Some examples of chemical synapses are when the blood makes excess platelets and other clotting factors to form clots. An electrical synapse is walking or running.

7. Different Functions of the Nervous System The nervous system is grouped in different functions. The motor division is the part of the system that moves muscles and bones. The Sympathetic system is used in flight or fight situations and activates natural instincts in different situations. The Sensory receptor conducts impulses and sends them to the CNS.