STRUCTURAL AND FUNCTIONAL ORGANIZATION OF THE AUTONOMIC NERVOUS SYSTEM Flashcards
What system?
(1) Controls skeletal muscle
(2) Conscious, voluntary control
(3) Motor pathway: one neuron from CNS to effector
(4) Does include sensory neurons (from skin, skeletal muscles, and special sense organs)
(5) All release the neurotransmitter acetylcholine (Ach)
(6) The axon of a single somatic motor neuron extends from CNS all the way to skeletal muscle fibers
Somatic Nervous System
Three neurons in each pathway
Cell body #1 _____
Cell body #2______
Cell body #3 _____
in dorsal root ganglion
in spinal cord or brain stem
in thalamus; axon extends to cerebral cortex
Anterior spinothalamic tracts sense what?
1) Light touch sensation
2) Deep pressure sensation
Lateral spinothalamic tract senses what?
1) Pain Sensation
2) Temperature (hot vs cold) sensation
Autonomic nervous system is regulated by what?
hypothalamus and brainstem
Controls viscera: Smooth and cardiac muscle, and sweat and digestive glands
is unconscious, involuntary
Autonomic Nervous System
what a re the two divisions of the autonomic system?
sympathetic (S) and parasympathetic (P)
during S and P divisions what happens to
Heart
Digest
Heart
S= Stim
P= inhibit
Digestive organs
S= inhibit
P= stim
during S and P divisions what happens to
Heart
Digest
Heart
S= Stim
P= inhibit
Digestive organs
S= inhibit
P= stim
Sympathetic preganglionic neurons
what spinal chord segments?
T1 to L2
“thoracolumbar division”
One sympathetic preganglionic axon can synapse with ______ postganglionic neuron cell bodies
20 or more
What CN carries 80% of all P nerve impulses
Vagus nerves CN 10
what CNs and spinal segments make up the preganglionic neurons
CN III, VII, IX, and X
S2-S4
Parasympathetic postganglionic neurons provide what type of effect, due to being located within or near the innervated organ?
precise, localized (not widespread) effects
these effects are these a result of ____
(a) Increase heart rate and contraction, and blood pressure (BP)
(b) Dilate pupils
(c) Dilate airways
(d) Dilate vessels to skeletal muscles, heart, liver and adipose tissue
(e) Constrict blood vessels to nonessential organs: skin, GI tract, kidneys
(f) Mobilize nutrients for energy: glucose and fats
Sympathetic Effects
(Fight-or-flight activities)