AP Ch 9 Flashcards
(know) axons carry impulses away from the neuron cell bodies and dendrites carry impulses to the neuron cell bodies
…
___ carry impulses to the spinal cord and brain from all parts of the body. They are also called afferent neurons
sensory neurons
___ carry impulses away from the brain and spinal cord. They only conduct impulses to two kinds of tissue, muscle and glandular epithelial tissue. They are also called efferent neurons
motor neurons
___ conduct impulses from sensory neurons to motor neurons. They also connect with each other to form complex, central networks of nerve fibers. They are sometimes called Central or Connecting neurons
interneurons
The 3 main functions of glia
#1 hold functions neurons together and protect them #2 Regulation of neuron function #3 bring the various functions of nervous tissue together into a coordinated whole
___ attach to neurons and to small blood vessels, holding these structures close to each other
astrocytes
___ 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 acts as a microbe-eating scavengers. They surround the microbes, draw them into their cytoplasm, and digest them. They likewise help to clean up cell damage resulting from injury or disease
Microglia
___ holds nerve fibers together and produces the fatty myelin sheath that envelops nerve fibers located in the brain and spinal cord.
Oligodendrocytes
neurons with myelin-wrapped axons
myelinated fibers
gaps between adjacent Schwann cells
Nodes of Ranvier
The outer wrapped layer of a Schwann cell
neurilemma
a group of peripheral nerve fibers (axons) bundled together like the strands of a cable
nerve
groups of wrapped axons
fasicles
covers the whole nerve
epineurium
___ form the white matter of the brain and spinal cord
tracts
brain and spinal cord tissue composed of cell bodies and unmyelinated axons and dendrites
grey matter
nerve impulses
action potentials
basic type of neuron pathway
reflex arc
two-neuron arc consists of which neurons?
sensory and motor
three-neuron arcs consist of what neurons?
sensory, interneurons, and motor
a three-neuron arc reaction
withdrawal reflex
a group of nerve-cell bodies located in the PNS
ganglion
excitatory or inhibitory; regulates parasympathetic effectors; involved in memory
Acetylcholine (ACh)
Excitatory or inhibitory; regulates sympathetic effectors, involved in emotional responses
Norepinephrine (NE)
mostly inhibitory; regulates motor control; involved in emotions and moods
Dopamine
Mostly inhibitory; involved in sleep, emotions, and moods
serotonin
mostly inhibitory; involved in blocking pain
endorphins and enkephalins
signal from presynaptic to postsynaptic neuron
nitric oxide (NO)