25: The Autonomic Nervous System Flashcards
autonomic nervous system
Cardiac muscle, visceral muscle and glandular secretory activity are controlled by this
nerve
is basically a bundle of individual nerve fibers, can contain a mixture of sensory and motor nerve fibers
Nerve fiber
refers to the axons or dendrites of individual neurons (nerve cells)
fiber
Each individual nerve fiber is specialized, carrying only one particular kind of impulse
white ramus, l
a bundle of autonomic nerve fibers, (branches off the main spinal nerve)
gray ramus, l
a bundle of autonomic nerve fibers, (reconnects with the spinal nerve next to the white ramus allowing some of the autonomic fibers to return to the spinal nerve)
Autonomic sensory afferent fibers
conduct sensory impulses toward the central nervous system.
Autonomic motor efferent fibers
are organized differently, autonomic motor neuron cell bodies are found in the lateral horn of the spinal cord
Somatic motor neurons
associated with the spinal cord have their cell bodies in the anterior horn of the spinal cord
autonomic ganglion
The two fibers synapse with each other at an this (cluster of neuron cell bodies) somewhere between the CNS and the effector
preganglionic fiber
The nerve fiber originating from the CNS, shoirt
postganglionic fiber
The fiber that ultimately synapses with the effector, long
cranial autonomics
are associated with four pairs of cranial nerves
thoracolumbar autonomics
are found as part of spinal nerve pairs C-8 (cervical), T-1 through T-12 (thoracic) and L-1 & L-2 (lumbar).
sacral autonomics
are associated with sacral nerve pairs S-2, S-3 and S-4 (sacral).
Postganglionic motor neurons, l
have their cell bodies in the autonomic ganglia. These ganglia are categorized according to location. There are three types; paravertebral, prevertebral, terminal
paravertebral ganglia, l
are arranged along either side of the vertebral column. On each side, individual ganglia are interconnected to the ones above and below, and forming a “chain” of ganglia
prevertebral ganglia, l
are located just in front of the vertebral column. These ganglia are also interconnected by networks of nerves called plexuses
solar plexus
example of networks of nerves
thoracolumbar autonomics
ganglia receive preganglionic axons from this
cranial and sacral autonomic efferents
Send the Terminal ganglia preganglionic impulses
sympathetic division
includes all autonomic nerve pathways whose preganglionic fibers stem from the thoracolumbar region of the spinal cord. The “sympathetic” division comes to the aid of the body during times of stress., Norepinephrine
autonomic nervous system is divided into two divisions
sympathetic, parasympathetic
parasympathetic division
includes all autonomic nerve pathways whose fibers arise from the craniosacral branches of the CNS. Because the craniosacral nerves emerge above and below the sympathetic, they are called the “parasympathetics” (para = around), Conservation, acetylcholine
dual innervation
EX: The sympathetic fibers speed up the heart while parasympathetic fibers slow it down
cholinergic
At the neuromuscular junctions, fibers with acetylcholine as the transmitter
adrenergic
fibers that use norepinephrin
SYMPATHETIC Traits:
1: Nerve impulses from thoracolumbar
2. prevertebral and paravertebral ganglia
3: Metabolic energy is rapidly consumed.
4: pupils dilate, dry mouth, increased heart rate, more Oxygen, liver glucose depletion, adrenal glands, less urine, , no digestion, blood to skeletal, arrector piliu, sweat
PARASYMPATHETIC Traits:
1: Nerve impulses from craniosacral
2. terminal ganglia.
3: Metabolic energy is conserved
4: pupils constrict, wet mouth, increased heart rate, more Oxygen, liver glucose depletion, no adrenal glands, more urine, , digestion, blood to organs, no arrector piliu, no sweat
