Physiology of the Peripheral Nervous System

Question 0

Autonomic nervous system functions

Answer 0

Regulate the heart, regulate the secretory glands (salivary, gastric, sweat, bronchial), regulate smooth muscles (bronchi, blood vessels, urogenital system, GI tract)

Question 1

Divisions of the nervous system

Answer 1

Central nervous system (brain and spinal cord), peripheral nervous system: somatic motor, autonomic (ANS)
-parasympathetic, sympathetic

Question 2

Parasympathetic nervous system

Answer 2

Slow the heart rate, increase gastric secretions, empty the bladder, empty the bowel, focus the eye for near vision, constrict the pupil, contract bronchial smooth muscle

Question 3

PNS drugs

Answer 3

Digestion of food, excretion of waste, control of vision, conservation of energy

Question 4

Sympathetic nervous system functions

Answer 4

Regulate cardiovascular system, regulate body temperature, implement “fight or flight” reaction

Question 5

Homeostatic objectives of SNS

Answer 5

Maintain blood flow to the brain, redistribute blood flow during exercise, compensate for loss of blood

Question 6

SNS body temperature regulations

Answer 6

Regulate blood flow to the skin, promote secretin of sweat glands, induce piloerection

Question 7

Fight or flight response

Answer 7

Increase heart rate and blood pressure, shunting blood away from the skin/viscera and into skeletal muscle, dilate the bronchi to improve oxygenation, dilate the pupils, mobilize stored energy

Question 8

Sympathomimetic drugs

Answer 8

Primarily used for effects on heart and blood vessels, lungs

Question 9

Basic mechanisms by which ANS regulates physiologic processes

Answer 9

Patterns of innervation and control, feedback regulation, autonomic tone

Question 10

Patterns of innervation and control

Answer 10

Dual innervation opposed: HR, dual innervation complementary: erection and ejaculation, only one division: blood vessels

Question 11

Feedback regulation

Answer 11

Baroreceptor reflex and blood pressure, feedback loop, sensor/effector neurons

Question 12

Autonomic tone

Answer 12

Only one division provides basal control to organ

• Most organs: predominant tone is PNS
• Vascular system: predominant tone is SNS

Question 13

Neurotransmitters of the PNS

Answer 13

Acetylcholine, norepinephrine, epinephrine

Question 14

Acetylcoline

Answer 14

Employed at most junctions of the PNS

Question 15

Norepinephrine

Answer 15

Released by most postganglionic neurons

Question 16

Epinephrine

Answer 16

Released by adrenal medulla

Question 17

Receptors of the PNS

Answer 17

Cholinergic receptors (mediated by acetylcholine), adrenergic receptors (mediated by epinephrine and norepinephrine)

Question 18

Subtypes of cholinergic receptors

Answer 18

Nicotinic(N), nicotinic(M), muscarinic

Question 19

Subtypes of adrenergic receptors

Answer 19

Alpha1, alpha2, beta1, beta2, dopamine

Question 20

Apha1

Answer 20

Vasoconstriction, ejaculation, contraction of bladder, neck, and prostate

Question 21

Alpha2

Answer 21

Located in presynaptic junction, minimal clinical significance

Question 22

Beta1

Answer 22

Heart: increases heart race, force of contraction, velocity of conduction in AV node
Kidney: renin release

Question 23

Beta2

Answer 23

Bronchial dilation, relaxation of uterine muscle, vasodilation, glycogenolysis

Question 24

Dopamine

Answer 24

Dilates renal blood vessels

Question 25

Receptor specificity of adrenergic nuerotransmitters

Answer 25

Epinephrine: all alpha and beta, NOT dopamine
Norepinephrine: all alpha and beta1, NOT beta2 or dopamine
Dopamine: alpha1, beta1, dopamine