AP chapter 9 2.0 Flashcards
What 2 major types of cells are found in the nervous system and what do they do
neurons and glia …. neurons conduct impulses while glia are supporting cells
Each neuron consists of 3 parts :
#1 a main part called a neuron cell body #2 one or more branching projections called dendrites #3 and one elongated projection known as an axon
___ are the process or projections that carry impulses to the neuron cell bodies
dendrites
___ are the process that carry impulses away from the neuron cell bodies
axons
___ carry impulses to the spinal cord and brain from all parts of the body. They are also called afferent neurons
sensory neurons
___ carry impulses in the opposite direction - away from the brain and spinal cord. They do not conduct impulses to all parts of the body - only to two kinds of tissue - muscle and glandular epithelial tissue. They are also called efferent neurons
Motor neurons
Glia - or ___ - do not specialize in transmitting impulses. Instead, they are special types of supporting cells
neurogloia
What are functions of Glia
#1 hold the functioning neurons together and protect them #2 regulation of neuron function #3 bring the various functions of nervous tissue together into a coordinated whole
Some glia cells are relatively large cells that look somewhat like stars because of the threadlike extensions that jut out from their surfaces. They attach to neurons and to small blood vessels, holding these structures close to each other
astrocytes
Astrocyte branches form a two layer structure called the ___. It separates the blood tissue and nervous tissue to protect vital brain tissue from harmful chemicals that might be in the blood
blood brain barrier (BBB)
___ remain stationary, but in inflamed or degenerating brain tissue, they enlarge, move about, and act as micro eating scavengers. They surround the microbes, draw them into their cytoplasm and digest them
Microglia
The ___ help to hold nerve fibers together and they produce the fatty myelin sheath that envelops nerve fibers located in the brain and spinal cord (myelin sheath affects nerve conduction speed)
oligodendrocytes
___ are glial cells that also form myelin sheaths but do so only in the PNS
schwann cells
Neurons with myelin-wrapped axons are called
myelinated fibers
___ are gaps between adjacent Schwann cells
nodes of the river