The Nervous Systemnervous_system.jpg - by Maggie Grady


The Nervous System helps the body send messages back and forth throughout the body. For example, if someone touches a hot iron the nerves in their finger will send a message to the brain and the brain will relay a message saying that the iron is hot and their finger needs to be removed.
The nervous system is composed of two different parts. They are the Central Nervous System(CNS) and the Peripheral Nervous System(PNS), both of these combined help transmit signals all throughout the body.

Structure/Function

Central Nervous System

The CNS is in charge of the brain and the spinal cord. The spinal cord allows messages from the PNS to get to the brain.

Peripheral Nervous System

The PNS is split into the Somatic and the Autonomic. The PNS contains all of the nerves that is not included in the Central Nervous System. These nerves connect to the brain and spinal cord and that is what allows signals to communicate with the rest of the body.
  • Somatic has control of the skeletal muscels and the senses in the body. The Somatic system is voluntary. However, the skeletal muscles are an exception.
  • Autonomic in charge of the involuntary muscles.These include the cardiac muscles and the smooth muscles.

Enzymes/Hormones

The Nervous system contains cells called neurons. Neurons help send messages throughout the body. The parts of a neuron are: dendrites, axons, synapse, and the cell body. Each one of these have different functions.
  • Dendrites receive information from other cells and then sends and electrical impulse to the cell body.
  • Axons transmit the neural signal.
  • Synapse is where a dendrite connects to another neuron
  • Cell Body is also known as the soma, makes proteins for dendrites and the other parts of the neuron.
Neurotransmitters are also important to the Nervous System. They help signals cross the synapse of one neuron to another. Neurotransmitters can also be located on the end of an axon for motor neurons. There are some special types of neurotransmitters that help the Nervous System function and they are:
  • Acetylcholine helps stimulate muscles and it also plays a role in sleeping.
  • Norepinephrine is said to help the Nervous system to be in high alert. Norepinephrine is important in increasing heart rate and blood pressure.
  • Dopamine is the "feel good" neurotransmitter. Dopamine can hinder the body or reward it. For example, too much dopamine can block the ends of a neuron and cause schizophrenia, but not enough can cause Parkinson's disease which can cause uncontrollable muscle tremors.
  • Endorphine helps with pain in the body.

Regulation

Peripheral Nervous System
  • Autonomic helps maintain homeostasis.

Communication

The Nervous System is like Facebook it connects all of the other body systems together. It sends and receives signals throughout the body allowing people to perform their daily functions. Within the Nervous system itself the CNS and the PNS rely on each other to get the information throughout the body.
Diagram of the Nervous System
Diagram of the Nervous System

Diagram of a neuron
Diagram of a neuron

Sources:
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/CNS.html
http://psychology.about.com/od/biopsychology/ss/neuronanat_2.htm
http://psychology.about.com/od/biopsychology/ss/neuronanat_5.htm
http://www.cerebromente.org.br/n07/fundamentos/neuron/parts_i.htm
http://www.thinkbody.co.uk/papers/autonomic-nervous-system.htm
http://webspace.ship.edu/cgboer/genpsyneurotransmitters.html
http://www.nda.ox.ac.uk/wfsa/html/u05/u05_010.htm