nerve_drug

nerve_drug - The Nervous System The Nervous System and...

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8/5/10 1 The Nervous System and Drugs The Nervous System CENTRAL NERVOUS SYSTEM ( CNS) : composed of the brain & spinal cord PERIPHERAL NERVOUS SYSTEM (PNS) : nerves that connect the CNS to all other parts of the body, such as muscles, internal organs, sense organs, etc., relay information to and from the CNS The Nervous System AUTONOMIC NERVOUS SYSTEM (ANS) : ANS controls functions not normally under conscious control - heart rate, breathing, temperature, hormonal regulation, your fight or flight system The Nervous System The brain can be divided into three parts; the forebrain , the midbrain , and the hindbrain . The Brain The forebrain is composed of the hypothalamus, the thalamus, and the cerebrum. The hypothalamus controls the body's internal environment, such as temperature, thirst, and sleep. The thalamus serves as a relay station from the PNS to the cerebrum , which controls consciousness and thought processes.
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8/5/10 2 The midbrain is relatively small and functions mainly as an information relay for sensory and motor information. The hindbrain is composed of the medulla oblongata, and the cerebellum. The medulla oblongata works with the spinal cord in controlling life support functions such as heart rate and breathing. The cerebellum serves to coordinate body movement. The brain, spinal cord and peripheral nerves are all composed of nerve cells, called neurons . typical neurons Damaged axons may regenerate but dead neurons are lost forever. A neuron consists of a cell body with many thin branches called dendrites . A neuron also has a long, thin portion called an axon , which has many branches and transmits signals to the dendrites and cell bodies of other neurons. Axons are often covered with a layer of fatty insulation known as a myelin sheath . At the point where an axon from one nerve cell contacts a dendrite from another, there is a very small gap called a synapse . Nerve impulses, which can be detected as electric current, travel one-way along the axon of a neuron and cause special chemicals, called neurotransmitters , to be released into the synapse. Neurotransmitters are contained in vesicles at the ends of axons.
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8/5/10 3 When neurotransmitters are released into the synapse they associate .!+ *(±²!3² )±²±(+') sites on the dendrite. This can induce current 4'. + )',³ + ± dendrite and thereby continue the signal.
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This document was uploaded on 11/01/2011 for the course BSC bsc1005l at FSU.

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nerve_drug - The Nervous System The Nervous System and...

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