Chapter 14: The Autonomic Nervous System

Question 1

ANS consists of motor neurons that…

Answer 1

innervate smooth muscle, cardiac muscle, and glands

Question 2

Somatic Nervous System

Answer 2

voluntary; each motor neuron extends from CNS to its effector (skeletal muscle); cell bodies located in CNS and axons heavily myelinated; neurotransmitter is acetycholine; stimulatory

Question 3

Autonomic Nervous System

Answer 3

visceral NS; involuntary; 2 motor neurons connect CNS to effectors (cardiac, smooth muscle, or glands); has preganglionic and postganglionic neurons

Question 4

Preganglionic Neurons

Answer 4

extends from CNS to postganglionic neuron; cell body located in CNS; axons lightly myelinated; releases ACh

Question 5

Postganglionic Neurons

Answer 5

extends from presynaptic neruons to effector; cell body lcoated in a autonomic ganglion; axon nonmyelinated; releases either ACh or noepinephrine; stimulatory or inhibtory

Question 6

Subdivision of ANS

Answer 6

parasympathetic and sympathetic divsions innervate same visceral organs (dual innervation), but have opposite effects; work together to maintain homeostasis

Question 7

Parasympathetic Division

Answer 7

rest and digest; craniosacral division; promotes maintenance functions (digestion, defacation, urination) and conserves energy; fibers exit CNS in cranial nerves III, VII, IX, and X and from S2-S4 region of spinal cord; preganglionic fibers long; postganglionic fibers short; both are cholenergic (release ACh); terminal ganglion located in or near visceral effecotr organs

Question 8

Sympathetic Division

Answer 8

fight or flight; thoracolumbar division; mobilizes body during action (exercise, excitement, emergency, embarrassment); reduces non-essential activities; fibers exit from lateral horns of T1-L2 region of spinal cord; preganglionic fibers short and cholinergic (release ACh); post gangliionic fibers long and adrenergic (release NE); ganglia located near spinal cord

Question 9

Preganglionic and Postganglionic Sympathetic Neurons can Synapse at 3 Different Locations

Answer 9

within a sympathetic trunk ganglion at the same time; within sympathetic trunk ganglion at a higher or lower level; pass through sympathetic trunk to synapse in a collateral ganglion anterior to the vertebral column

Question 10

What stimulates the adrenal medulla directly?

Answer 10

preganglionic sympathetic neurons; parasympathetic system has nothing to do with adrenal galnds

Question 11

Autonomic (Visceral) Reflexer

Answer 11

autonomic reflex arcs have same 5 components as somatic reflex arcs; there are differences: afferent fibers are visceral sensory rather tahn somatic sensory neurons, 2 consecutive motor neurons, effectors are smooth muscle, cardiac muscle and/or glands; ex) pupillary reflex, vomiting reflex, defacation reflex, micturition reflex

Question 12

Hypothalamus is the…

Answer 12

main integration center of ANS–coordiantes heart activity, blood pressure, water balance, and endocrine activity

Question 13

Spinal cord is the..

Answer 13

main integraition center for micturition and defacation but are subject to conscious inhibition (holding/waiting to use the bathroom)

Question 14

KNOW THE CHART WITH THE DIVISIONS AND STUFF