Psychology : Semester I : Biological Basis of Behavior

Sections:

Introduction  |   Section 1  |  Section 2  |   Section 3 | Section 4 | Section 5 | Section 6

Psychology : Biological Basis of Behavior : Section Three The neuron and the nervous system The nervous system is divided into two general divisions. The central nervous, which consists of the brain and the spinal cord, is one division. The second division is the peripheral nervous system, which is divided into the somatic nervous system (the skeletal muscles) and the autonomic nervous system (the gland and internal organs).  The autonomic nervous system is further broken down into the sympathetic nervous system (gets the body ready for action) and parasympathetic nervous system (brings the body back to homeostasis or normal situation). The neuron or nerve cell is the basic unit of the nervous system. Neurons make up the communication network throughout the body.  They carry messages all over the body.   The neuron consists of three basic parts that enable it to communicate with other neurons. The first part is the dendrite, a tree-like process, which carries the information to the cell body from other neurons. The second part is the cell body which contains a nucleus and is the part that will decide if the neuron will fire or not and it also directs the building of the neurotransmitters. The third part is the axon and its job is to carry information to other neurons. Some neurons are covered with a fatty sheath, called myelin and it allows the message to travel faster.  Neurons are not connected and have a space between them, called a synapse. The message travels down the neuron from dendrite to cell body to axon over the synapse to other dendrites etc. Since an axon has many terminals at its end an axon can connect with many other neuron dendrites. The neural connections that are present correlate with intelligence. Neurotransmitters are stored in the axon terminals in structures called synaptic vesicles. These chemicals will bridge the synapse gap to carry the message on. Neurons communicate with each other by chemical and electrical messages.  When a nerve is stimulated, an action potential (a change in the electrical voltage between the inside and outside of an axon) occurs and produces an electrical impulse which travels down the axon.  This electrical message travels down the length of the axon and when it gets to the end of the axon terminals it stimulates chemicals inside the synaptic vesicles, called neurotransmitter, to diffuse out and carry the message across the synapse like a bridge to the receptor dendrites of other neurons. Over a hundred neurotransmitters have been identified that have many different effects on the body. For example Dopamine is a neurotransmitter that in abundance has a link to the mental disorder, schizophrenia.  A lack of dopamine is associated with Parkinson’s disease.  Another example is the neurotransmitter, acetylcholine, which helps regulate the heart muscle and messages between the brain and spinal cord. Depletion of acetylcholine is associated with the Alzheimer’s disease.  A final example is the neurotransmitter serotonin which is associated with moods, emotions concentration and may play a part in the mental disorder of depression. You can see the importance of neurotransmitters in the activity of the brain and behavior. The approach of neurobiology believes that understanding of the role and function of neurotransmitters will help us understand human behavior. Try this crossword puzzle Now go to the Assignment Folder in Schoology to complete the required assignments for this section. Next Section!

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