Chapter 9 Flashcards
What is the function of the nervous system?
Responsible for communication & coordination of all body functions
Central Nervous System
Brain & Spinal Cord
Peripheral Nervous System
Any nerves outside of the CNS, connects the rest of the body with the CNS. Autonomic nervous system
What is the main function of a neuron?
To conduct a nerve impulse
3 parts of a neuron
Cell body, dendrites and axon
What do dendrites do?
Receiving/input fibers
What do axons do?
Sends signal out
What are the three types of neurons?
Sensory, Interneurons, and Motor
Purpose of axon terminals?
Storage spot for chemical neurotransmitters
Purpose of myelin sheath
covering layer of white fatty material that protects & insulates the nerve fibers. Increases the speed of transmission.
Purpose of Nodes of Ranvier
Gaps in the myelin sheath, allows for electrical impulse to travel more quickly.
Neuroglia of the CNS?
Astrocytes, oligodendrocytes, microglia and ependymal cells.
Neuroglia of the PNS?
Swchann cells, Satellite cells
Astrocytes
“star cells” prevents blood toxins from entering the nervous system
Microglia
Smaller astrocytes
Oligodendrocytes
Help hold nerve fibers together. Produce myelin sheath.
Ependymal cells
Line the inside of the ventricles of the brain & spinal cord. Produce CSP.
Satellite Cells
Flat cells around the cell body. Provide structural support.
Schwann Cells
Form the myelin sheath that is wrapped around an axon = neurolemma
White Matter
Appears white from the myelinated fibers. Found in the CNS and PNS
Gray Matter
Consist of cell bodies, interneurons and unmyelinated fibers. Dispersed throughout the white matter.
Diverging
One presynaptic neuron influences several postsynaptic neurons. ex: muscle fibers
Converging
Several presynaptic with one specific postsynaptic neuron. Ex: receptor neuron receiving information from several muscle fibers.
Reverberating circuits
A presynaptic neuron causes the postsynaptic neuron to send a series of nerve impulses. Ex: breathing.
