Chapter 15: Visceral Reflexes

Question 1

autonomic nervous system

Answer 1

a motor nervous system that controls viscera organs

Question 2

autonomic nervous system carries out actions _____

Answer 2

involuntarily

Question 3

Visceral reflexes make it all the way to the _______

Answer 3

brainstem

Question 4

parasympathetic division

Answer 4

rest & digest

digestion and waste elimination

Question 5

autonomic tone

Answer 5

normal background rate of activity that represents the balance between parasympathetic and sympathetic systems as the body changes

Question 6

parasympathetic tone

Answer 6

maintains smooth muscle tone in intestines

Question 7

sympathetic tone

Answer 7

maintains blood pressure and keeps blood vessels constricted

Question 8

ANS has components in the ___ and the ___such as what?

Answer 8

central and peripheral
nucleus of hypothalamus
motor neurons in spinal cord and peripheral ganglia

Question 9

somatic vs. visceral motor pathway

Answer 9

somatic: myelinated axon reaches all the way to the skeletal muscle
visceral: must travel across two neurons to get to the target organ

Question 10

What are the 2 signals in autonomic output pathways?

Answer 10

presynaptic neuron cell body in CNS

postsynaptic neuron cell body in peripheral ganglion (reaches target organ cell & takes longer)

Question 11

Why does the postsynaptic neuron signal take longer?

Answer 11

because the cell loses its myelination

Question 12

sympathetic division is also called the _____

Answer 12

thoracolumbar division (thoracic and lumbar regions)

Question 13

sympathetic division has ____ preganglionic fibers which are found in the ___ ____and ____ postganglionic fibers

Answer 13

short;lateral horn; long

Question 14

chain of ganglia

Answer 14

paravertebral ganglion

Question 15

sympathetic division preganglionic fibers are _____ and _____ while the postganglionic fibers are ____ .

Answer 15

short myelinated

unmyelinated

Question 16

what are 3 outcomes of the preganglion of sympathetic chain

Answer 16

• end in ganglia
• travel up and down the chain
• pass through the chain without synapsing

Question 17

how can nerve fibers leave the sympathetic chain? (3)

Answer 17

• spinal nerves
• sympathetic nerves
• splanchnic nerves

Question 18

spinal nerve route

Answer 18

making it through without synapse

exit ganglion by way of gray ramus and return to spinal nerve and travel the rest of the way to the target organ

Question 19

splanchic nerve route

Answer 19

T5 to T12 pass through the ganglia without synapsing

Question 20

What are the 3 major collateral ganglia in the abdominal aortic plexus?

Answer 20

• celiac
• superior mesenteric
• inferior mesenteric

Question 21

adrenal glands

Answer 21

on top of the kidneys

Question 22

parasympathetic division is called the _____

Answer 22

craniosacral division (brain to sacral region)

Question 23

parasympathetic division has ____ preganglionic fibers which are found in the ___ ____and ____ postganglionic fibers

Answer 23

long; cranial nerves (3,7,9,10); short

Question 24

___ ____ is less in the parasympathetic division than in the sympathetic division

Answer 24

neural divergence (wide spread effects)

Question 25

enteric nervous system (3)

Answer 25

GUT

• nervous system of the digestive tract
• does not arise from the brainstem or spinal cord (no components in CNS)
• has own reflex arcs

Question 26

megacolon

Answer 26

massive dilation of bowel accompanied by abdominal distension & chronic constipation (WE NEED FIBER)

Question 27

hirschsprung disesase

Answer 27

hereditary defect causing absence of the enteric system that will not allow passage of feces

Question 28

All autonomic fibers secrete either ____ or ____

Answer 28

ACh or NE

Question 29

____ is secreted by all pregang neurons in both divisions and all postgang ____ divisions

Answer 29

ACh; parasympathetic

Question 30

What are 2 types of cholinergic receptors?

Answer 30

muscarinic receptors (all cardiac muscles, smooth muscles,and gland cells)
nicotonic receptors (all post gang neurons of ANS)

Question 31

___ is secreted by nearly all ______ postgang neurons

Answer 31

NE; sympathetic

Question 32

alpha adrenergic receptors

Answer 32

usually excitatory

Question 33

beta adrenergic receptors

Answer 33

usually inhibitory

Question 34

Which effects tend to last longer than the other?para or sym? why?

Answer 34

sympathetic; because Ach released by parasympathetics is broken down quickly in synapse

Question 35

dual innervation

Answer 35

most viscera receive nerve fibers from both para and sympathetic divisions but don’t innervate an organ equally

Question 36

dual innervation has ___ effects that oppose each other and ____ effects that produce a unified overall effect

Answer 36

antagonistic and cooperative

Question 37

An example of a cooperative effect is?

Answer 37

saliva

Question 38

What effector only receive sympathetic fibers

Answer 38

adrenal medulla

Question 39

metics:____ while lytics:_____ sympathetic activity

Answer 39

enhance; suppress

Question 40

in ANS the cerebral cortex

Answer 40

has an influence: anger, fear, anxiety

Question 41

in ANS the hypothalamus

Answer 41

nuclei for primitive functions such as hunger, thirst, sex

Question 42

in ANS midbrain, pons, and medulla oblongata

Answer 42

salivation, swallowing, bladder control

Question 43

vasomotor tone

Answer 43

a baseline firing frequency of sympathetics that keeps vessels in state of partial constriction

Question 44

increase firing frequency

Answer 44

vasoconstriction

Question 45

decrease firing frequency

Answer 45

vasodilation