Chapter 15 - Autonomic Nervous System

Question 1

Parasympathetic

Answer 1

Rest and Digest, Craniosacral, Preganglionic fiber long and postganglionic fiber is short, both synapse release ACh. Preganglionic fiber is lightly myelinated, synapse with ACh to postganglionic nonmyelinated axon. Postganglionic synapses to effector organ (smooth muscle) with ACh

Question 2

Sympathetic

Answer 2

Fight or Flight, Orginates out of lateral horn of thoracolumbar spinal cord, axon projects through ventral spinal root and nerve to sympathetic ganglion. Lightly myelinated preganglionic axons synapse with nonmyelinated postganglionic and releases ACh. Postganglionic neuron synapses with effector organ and releases Norepinephrine. Can also synapse to Adrenal Medulla to release Epinephrine and Norepinephrine into the blood stream for quicker response.

Question 3

Autonomic NS

Answer 3

2 neuron chain, preganglionic neuron release ACh, effect is either stimulatory or inhibitory, controls cardiac and smooth muscle and glands

Question 4

Dual innervation

Answer 4

All visceral organs served by both divisions, but cause opposite effects, maintains homeostasis

Question 5

Components of a Visceral Reflex

Answer 5

1. ) Receptor in Viscera
2. ) Visceral Sensory Neuron
3. ) Integration Center (preganglionic neuron, dorsal horn interneuron, or within walls of gastrointestinal tract)
4. ) Motor neuron (2-neuron circuit, postgang- and pregang)
5. ) Visceral effector

Question 6

Cholinergic Fibers

Answer 6

Release NT ACh, All ANS preganglionic axons, all parasympathetic postgang axons. 2 types of receptors bind to ACh - Nicotinic & Muscarinic

Question 7

Adrenergic Fibers

Answer 7

Release NT NE, most sympathetic postganglionic axons (minus sweat glands)

Question 8

Nicotinic Receptors

Answer 8

Found on sarcolemma of skeletal muscle cells at NMJ.
All postgang- neurons
Hormone-producing cells of adrenal medulla
Effects are always Stimulatory

Question 9

Muscarinic Receptors

Answer 9

All effector cells stimulated by postgang- cholinergic fibers
Effects can either be inhibitory or stimulatory, depends on receptor type of target organ

Question 10

Adrenergic Receptors

Answer 10

Major classes: Alpha (1 & 2) and Beta (1,2,3) 
Effects of NE depend on which subclass on target organ

Question 11

Atrophine

Answer 11

blocks muscarinic ACh receptors, used to prevent salivation during surgery and dilate pupils

Question 12

Over-Counter Drugs

Answer 12

Stimulate Alpha-Adrenergic Receptors

Question 13

Beta-Blockers

Answer 13

Drugs that attach to Beta 2 receptors to dilate lung bronchioles in asthmatics

Question 14

Sympathetic Tone

Answer 14

(Vasomotor tone) Keeps blood vessels in continual state of partial constriction. Relationship between sympathetic ns and blood pressure, even at rest. Vascular system is innervated by sympathetic fibers

Question 15

Parasympathetic Tone

Answer 15

Dominates heart, smooth muscle of digestive and urinary tract organs and most glands except sweat and adrenal.

Question 16

Control ANS Function

Answer 16

Hypothalamus - main integrative center of ANS activity

Cerebral cortex, reticular formation, and spinal cord

Question 17

Hypothalamus Control

Answer 17

Heart Activity and blood pressure
Body Temp
water balance
endocrine activity
Emotional and biological drives
Reactions to fear, stress

Question 18

Biofeedback

Answer 18

Awareness of physiological conditions with goal of consciously influencing them.
Training allows some to control migraines and manage stress.