Exam 4- Autonomic Nervous System

Question 1

is the ANS a sensory or motor division?

Answer 1

motor

Question 2

autonomic nervous system definition

Answer 2

system of motor neurons that (involuntarily) innervates smooth muscle, cardiac muscle, and glands

Question 3

subdivisions of ANS

Answer 3

sympathetic and parasympathetic

Question 4

autonomic motor units

Answer 4

2-neuron motor chain
preganglionic cell body in CNS
preganglionic synapses with postganglionic in autonomic ganglia outside CNS
postganglionic axon that extends to effector

Question 5

peripheral motor units

Answer 5

in spinal cord
1 single motor neuron goes all the way from CNS to effector organ
uses ACh
goes to skeletal muscle

Question 6

autonomic motor units are (monosynaptic/polysynaptic)?

Answer 6

polysynaptic

Question 7

peripheral motor units are (monosynaptic/polysynaptic)?

Answer 7

monosynaptic

Question 8

parasympathetic- where do fibers emerge from CNS?

Answer 8

brain and sacral region of spinal cord

Question 9

parasympathetic- what are the length of motor unit fibers?

Answer 9

long preganglionic

short postganglionic

Question 10

parasympathetic- where are ganglia located?

Answer 10

in visceral effector organs

Question 11

parasympathetic- what is the function?

Answer 11

converses energy; does housekeeping tasks

Question 12

parasympathetic- are preganglionic neurons generally polysynaptic or monosynaptic?

Answer 12

monosynaptic

Question 13

parasympathetic- how does the neurotransmitter work?

Answer 13

ACh is quickly inactivated by acetylcholinesterase

ACh acts directly and rapidly on effectors

Question 14

sympathetic- where do fibers emerge from CNS?

Answer 14

thoracic and lumbar regions of spinal cord

Question 15

sympathetic- what are the length of motor unit fibers?

Answer 15

short preganglionic

long postganglionic

Question 16

sympathetic- what is the function?

Answer 16

mobilizer; fight or flight

Question 17

sympathetic- are preganglionic neurons generally polysynaptic or monosynaptic?

Answer 17

monosynaptic

Question 18

sympathetic- how does the neurotransmitter work?

Answer 18

NE is slowly inactivated by reabsorption
NE acts indirectly (using 2ndary messengers) and more slowly on effectors
NE is also released into bloodstream by adrenal medulla

Question 19

dual innervation

Answer 19

both divisions of ANS go to the same place

Question 20

visceral reflex arc components

Answer 20

receptor
visceral sensory neuron
integration area (spinal cord)
2-neuron motor chain
effector (smooth muscle and glands)

*same basic path as spinal reflex, only difference is 2-neuron motor chain rather than 1

Question 21

neurotransmitters released by ANS

Answer 21

acetylcholine

norepinephrine

Question 22

acetylcholine is released by…

Answer 22

all preganglionic axons
all parasympathetic postganglionic axons (by cholinergic fibers)
some sympathetic postganglionic axons

Question 23

which sympathetic postganglionic axons release ACh?

Answer 23

those that innervate sweat glands, blood vessels in skeletal muscle, and external genitalia

Question 24

norepinephrine is released by…

Answer 24

most sympathetic postganglionic axons

Question 25

cholinergic receptors

Answer 25

receptors that bind to ACh nicotinic receptors muscarine receptors

Question 26

nicotinic receptors

Answer 26

all postganglionic neurons adrenal medulla produces ACh ACh always stimulatory/excitatory

Question 27

muscarinic receptors

Answer 27

on all parasympathetic target organs on these sympathetic postganglionic: eccrine sweat glands, some blood vessels of skeletal muscle, genitals ACh can be stimulatory or inhibitory

Question 28

adrenergic receptors

Answer 28

found on most sympathetic receptor organs alpha beta

Question 29

alpha receptor

Answer 29

NE usually stimulatory | leads to depolarization

Question 30

beta receptor

Answer 30

NE usually inhibitory | leads to hyperpolarization

Question 31

ANS controls structures

Answer 31

reticular formation hypothalamus cerebral cortex spinal cord

Question 32

reticular formation

Answer 32

part of brain that sends signals to cerebral cortex to keep it active (keeps cerebrum awake) mechanism that has the most direct influence on ANS

Question 33

hypothalamus

Answer 33

main integration center for ANS anterior: parasympathetic posterior: sympathetic

Question 34

cerebral cortex

Answer 34

activity on ANS is mostly subconscious (through memory)

Question 35

spinal cord

Answer 35

activation of reflex directly through spinal cord | thirst, defamation reflex

Question 36

Hypertension and its symptoms

Answer 36

disorder of overactive sympathetic division of ANS | symptoms: high bp, stroke, heart attack/failure, kidney disease/failure, sexual dysfunction, vision loss

Question 37

raynauds disease

Answer 37

disorder of sympathetic division of ANS vasoconstriction in extremities in response to cold characteristic sign: v pale fingers/toes

Question 38

how does raynauds work

Answer 38

1. cold causes blood vessels supplying extremities to constrict 2. blood supply is reduced 3. those areas get cold