ANS - Lecture 2

Question 1

cranial nerve X also called ____ ____ carries 75% of

Answer 1

• vagus nerve
• all parasympathetic fibers innervating various organs

Question 2

cranial nerve that innervates heart, lungs and various parts of the intestinal tract

Answer 2

vagus nerve or cranial nerve X

Question 3

the PSNS ganglia are found

Answer 3

close to the organ or within the walls of the organ

Question 4

The functions of the parasympathetic system dominate during the

Answer 4

rest/digest response

Question 5

T/F adrenal medulla is innervated by parasympathetic fibers

Answer 5

False - no parasympathetic innervation

Question 6

T/F smooth muscles of most blood vessels in the body receive parasympathetic innervation

Answer 6

False; exception is penis and clitoris

Question 7

what is meant by dual autonomic innervation?

Answer 7

innervation of organ/tissues from both the SNS and PSNS

Question 8

Tone in DAI is

Answer 8

a background level of activity maintained by both SNS and PSNS

Question 9

The SNS and PSNS are activated reciprocally meaning

Answer 9

the increase in activity of one system will decrease the activity of the other system

Question 10

one division turns up its activity and the other turns down its acitivity; this is to

Answer 10

give more control over body responses

Question 11

what are the exceptions of dual innervation

Answer 11

adrenal medulla, most blood vessels and sweat glands; receive parasympathetic innervation only

Question 12

T/F the sympathetic system is always excitatory and the parasympathetic system is always inhibitory

Answer 12

False - depends on target tissue, neurotransmitter and receptor to which it binds

Question 13

chemical transmitters of the ANS and what they release

Answer 13

• cholinergic: releases ACh
• adrenergic: releases NE

Question 14

Preganglionic neurons release ____ in both he SNS and PSNS

Answer 14

ACh

Question 15

The major transmitter at all ganglia in the ANS

Answer 15

acetylcholine

Question 16

PS postganglionic fibers release

Answer 16

ACh at target tissues

Question 17

S postganglionic fibers innervating MOST of the target tissues release

Answer 17

NE at target tissues

Question 18

ACh is released by S postganglionic fibers at

Answer 18

SOME of the innervated target tissues

Question 19

** see slides for events at a cholinergic nerve terminal

Question 20

ACh is synthesized from

Answer 20

acetyl CoA and choline in the nerve terminal

Question 21

what enzyme catalyzes events at the cholinergic nerve terminal?

Answer 21

choline acetyltransferase

Question 22

Ach binds to receptors on the membrane of the _________ neuron called

Answer 22

• postsynaptic
• cholinergic receptors

Question 23

enzyme that breaks down ACh to choline and acetate

Answer 23

acetylcholinesterase

Question 24

What is varicosity, what type of neuron does it occur on?

Answer 24

• swellings along the axon branches
• both S and PS postganglionic neurons

Question 25

site where the neurotransmitters are made and stored in vesicles

Answer 25

varicosities

Question 26

what function do varicosities have in neurotransmitter release?

Answer 26

• releases neurotransmitters along a significant length of the axon and therefore over a large surface area of the effector tissue

Question 27

NE is synthesized from

Answer 27

the amino acid tyrosine

Question 28

tyrosine is converted to

Answer 28

dopa and dopamine

Question 29

How is norepinephrine recycled?

Answer 29

a special transport system that can take the whole molecules of norepinephrine back up into the varicosity

Question 30

ACh is released at

Answer 30

• all autonomic ganglia
• parasympathetic postganglionic fibers
• sympathetic preganglionic fibers innervating sweat glands and blood vessels in skeletal muscles

Question 31

NE is released at

Answer 31

• most sympathetic postganglionic fibers
• adrenal medulla (along with E)

Question 32

Cholinergic receptors bind to ____ and the two types are:

Answer 32

• ACh
• nicotinic, muscarinic

Question 33

Nicotinic receptors found in skeletal muscles (Nm) are responsible for ______ _______ in what nervous system?

Answer 33

muscle contraction
somatic nervous system

Question 34

Nicotinic receptors found on the cell bodies of the postganglionic neurons (Nn) are responsible for: in what nervous system?

Answer 34

• the production of an EPSP
• PSNS and SNS

Question 35

what contains the Nn type of nicotinic receptor?

Answer 35

cell bodies of all postganglionic neurons (SNS and PSNS) and adrenal medulla

Question 36

Adrenergic receptors bind

Answer 36

NE or E

Question 37

2 types of adrenergic receptors

Answer 37

alpha (2 subtypes)
bets (3 subtypes)

Question 38

Adrenergic receptors are ____________ receptors meaning the binding of NE/E to the receptor causes excitation/inhibition of the target tissue through a ___________ coupled mechanism

Answer 38

• metabotrophic
• G-protein

Question 39

membrane-bound receptor proteins that respond to ligand binding by opening an ion channel and allowing ions to flow through

Answer 39

ionotropic

Question 40

see the document for structures and mechanisms of nicotinic, muscarinic and adrenergic receptors

Question 41

convergence in the ANS is when

Answer 41

numerous preganglionic neurons form synapses with a single postsynaptic neuron

Question 42

divergence is when

Answer 42

a small number of presynaptic neurons form synapses with a larger number of postsynaptic neurons

Question 43

in the ANS, divergence exists at the

Answer 43

ganglia

Question 44

______ nervous system exhibits a greater degree of divergence than the ______ nervous system

Answer 44

sympathetic
parasympathetic

Question 45

in the PSNS, the ratio of preganglionic neuron synapsing with postganglionic neuron is between ____ and ____ meaning more specific/localized

Answer 45

1, 3

Question 46

In the SNS the ratio of preganglionic neuron to postganglionic neuron can be anywhere between ___ and ____ meaning a more diffuse response

Answer 46

1, 20