Chapter 15

Question 1

ANS contributes to homeostasis by ? (2)

Answer 1

1) responding to subconscious visceral sensations
2) exciting/inhibiting smooth/cardiac muscle & many glands

Question 2

Biggest difference between ANS & SNS

Answer 2

involvement of conscious control

in SNS, feedback via sensations are consciously percieved & skeletal muscle = main tool used for reflexive & voluntary movement

ANS usually operates without conscious control (though centers in hypothalamus & brain stem regulate ANS reflexes)

Interoceptors (sensory) receptors in BV, visceral organs, muscles & NS monitor internal conditions

• chemoreceptors → monitor blood CO2
• mechanoreceptors → detect stretch in organ walls & BVs

Question 3

Autonomic motor neurons regulate…

Answer 3

visceral activies by either increasing or decreasing ongoing activities in their effector tissues

Question 4

Why are some autonomic responses the basis for polygraphs?

Answer 4

because some autonomic responses can NOT be consciously altered

Question 5

Anatomy of all autonomic pathways can best be understood by picturing..

Answer 5

double-barrelled neuronal construct consisting of preganglionic neuron leading to intermediate ganglion (contains cell bodies of post-ganglionic neurons that innervate effector)

Question 6

Sensory Input

a) SNS
b) ANS

Answer 6

a) from somatic senses & special senses
b) mostly from interoceptors, some from ^

Question 7

control of motor output

a) SNS
b) ANS

Answer 7

a) voluntary control
b) involuntary

Question 8

motor neuron pathway

a) SNS
b) ANS

Answer 8

a) one-neuron pathway → somatic motor neurons from CNS synapse directly with effector
b) two-neuron pathway

Question 9

neurotransmitters & hormones

a) SNS
b) ANS

Answer 9

a) All somatic motor neurons release ACh
b) all sympathetic & parasympathetic preganglionic neurons release ACh

most sympathetic postganglionic neurons release NE , to sweat glands - release ACh

parasympathetic post-ganglionic neurons → ACh

Question 10

(2) divisions of ANS

Answer 10

parasympathetic

sympathetic

Question 11

Most body organs have __ __

Answer 11

dual innervation → recieve impulses from both sympathetic & parasympathetic neurons

Question 12

Sympathetic Division

• neuronal arrangement

Answer 12

single sympathetic preganglionic fibers synapses with many postganglionic branches (20 or more) to create diverging circuit

postganglionic axons terminate in several dif visceral effectors → making effects of sympathetic stimulation a widespread massive response

Question 13

Parasympathetic Division

• neuronal arrangement

Answer 13

• more controlled response

presynaptic parasympathetic neurons synapse with only 4-5 postsynaptic neurons → supply single visceral effector

→ leads to narrow, focused action on specific organs

Question 14

ANS Neurotransmitters

• how many used in entire NS?

Answer 14

over 100

Question 15

Chemicals used to transmit chemical messages in ANS (2)

Answer 15

acetylcholine (ACh)

norepinephrine (NE)

Question 16

Cholinergic

Answer 16

synapses at which ACh is used

Question 17

Adrenergic

Answer 17

synapses at which norepinephrine & epinephrine are used

Question 18

Cholinergic receptors

Answer 18

receptors that respond to ACh release by these cholinergic neurons

• integral membrane proteins in postsynaptic PM

Question 19

(2) subtypes of cholinergic receptors

Answer 19

1) nicotinic receptors
2) muscarinic receptors

Question 20

1) nicotinic receptors

found in?

Answer 20

found in ganglia, chromaffin cells of adrenal medulla & motor end plate of NMJ

Question 21

2) muscarinic receptors
- found?

Answer 21

found in synapses with effector organs

Question 22

Cholinergic neurons rekease ACh

• include?

Answer 22

1) all sympathetic & parasympathetic PREganglionic neurons
2) sympathetic POSTganglionic neurons that innervate most sweat glands
3) all parasympathetic POSTganglionic neurons

Question 23

Norepinephrine (NE) & Epinepinephrine (E) can be released as? by?

Answer 23

1) as neurotransmitter by sympathetic postganglionic neurons (NE)
2) as hormone into blood by chromaffin cells of adrenal medullae (NE & E)

Question 24

(2) main types of adrenergic receptors

Answer 24

1) alpha receptors
2) beta receptors
- found on visceral effectors innervated by most sympathetic postganglionic axons

Question 25

alpha & beta receptors are further broken down into…based on?

Answer 25

alpha-1

beta-1

• (excitation)

alpha-2

beta-2

• (inhibition)
• based on specific responses elicited & by their selective binding of drugs that activate/block them*

Question 26

Norepinephrine favors which adrenergic receptors?

Answer 26

alpha-1 & alpha-2

Epinephrine works on both receptors equally well

Question 27

Sympathetic Stimulation leads to? (7)

Answer 27

1) secretion of NE by adrenal glands
2) increase in rate/strength of heartbeat
3) constriction of BV on non-essential organs
4) dilation of essential organs’ vessels
5) increase of breathing rate/depth
6) conversion of glycogen → glucose
7) decrease in GI activity

Question 28

Responses of Parasympathetic NS

• (6) increases
• (3) decreases

Answer 28

Increased: (SLUDD)

• salivation
• lacrimation
• urination
• digestion
• defecation

Decreased:

• rate/force of heartbeat (atrial)
• airway size & rate of breathing
• pupil size