Midterm paper

Module 10 LO1

Nervous System Functions

Dr. Lisa Brinn [email protected]

1. Nervous Tissue Functions • Nervous tissue - vascular tissue comprised of 2 cell types

• Neurons (nerve cells) • Neuroglia (glia cells)

• Subdivisions: • CNS

• Brain • Spinal cord

• PNS • Cranial nerves • Spinal nerves

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A. Neurons

• Comprise the circuitry connecting all regions of the body to the nervous system

• Highly specialized cells • Lost ability to undergo mitotic division • Neurons or nerve cells possess electrical excitability • Nerve impulse travels rapidly and at constant strength

• speeds ranging from 0.5 to 130 meters per second (1 to 280 mi/hr)

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B. Neuroglia • Smaller cells that greatly outnumber neurons • Forms half the volume of CNS

• Maintaining homeostasis • Support, nourish, and protect neurons

• Ability to multiply and divide in mature NS • Do not generate or propagate nerve impulses • Six types of neuroglia:

o CNS § Astrocytes, oligodendrocytes, microglia, and ependymal cells

o PNS § Schwann cells (neurolemmocytes) and satellite cells

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Functions

A. Maintaining homeostasis B. Receiving sensory input C. Integrating information D. Controlling muscles and glands E. Establishing and maintaining mental activity

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