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Flashcards in ANS Deck (140):
1

What are the two components of the nervous system?

CNS and PNS

2

The somatic and autonomic nervous system are a part of which division of the nervous system (CNS or PNS)?

PNS

3

The final common pathway linking the central nervous
system to skeletal muscles is what?

Alpha motor neurons

4

Efferent axons in the somatic nervous system synapse where?

on effector cells

5

What are the final common pathways from the CNS to peripheral target organs?

Sympa and parasymp neurons

6

Does the somatic system have ganglia?

no

7

Do the sympatheic and parasymp nerves have ganglia?

yes

8

How do presynaptic sympathetic neurons compare to postsynaptic side?

Short preganglionic
Long post

9

Parasympathetic ganglia cells are clustered where?

within walls of visceral organs

10

How do presynaptic PARAsympathetic neurons compare to postsynaptic side?

Long preganglionic
Short postganglionic

11

Why is the adrenal gland a special case of innervation?

No post synaptic--just hormones released into the blood

12

What are the two different types of stimuli that the ANS can have?

Excite or inhibit

13

The somatic α motor neurons are (BLANK) in diameter and therefore allow (BLANK) conduction

The somatic α motor neurons are larger in diameter and therefore allow faster conduction

14

Where are the cell bodies of the sympathetic division located?

In the intermediolateral columns of the spinal cord, in the thoraco-lumbar section

15

What are the spinal levels of the sympathetic division?

T1-L3/4

16

Axons for the preganglionic symp neurons exit the spinal cord and enter what structure?

White rami communicates

17

Are most preganglionic symp neurons myelinated or unmyelinated?

Myelinated

18

What are the three routes that sympathetic nerves take after leaving the spinal cord?

1. To symp chain, where they synapse
2. Through chain, and synapse in specialized ganglia
3. Straight to organ (e.g. adrenal medulla)

19

What are the two regions of the parasympathetic division?

1. Cranial outflow
2. Sacral outflow

20

Where parasympathetic nerves from the cranial division synapse?

Near the organ they innervate

21

Where parasympathetic nerves from the sacral division synapse?

in a
group of scattered pelvic ganglia

22

True or false: The pelvic ganglia carry both sympathetic and
parasympathetic fibers

True

23

What are the two division of the enteric nervous system? Where are they located?

Myenteric (between muscular layers of gut tube)

Submucosal layer (beneath circular muscularis mucosae)

24

What is the function of the myenteric plexus?

controls GI tract motiliy

25

What is the function of the submucosal plexus?

ion and fluid transport

26

True or false: The ENS, cannot function without input from the sympathetic or parasympathetic division.

False, it can

27

What is the ANS?

The portion of the nervous system that controls most VISCERAL functions, and accommodates coordinated responses to external stimuli

28

True or false: the somatic and ANS are a part of the CNS

False, only the PNS

29

What are the three divisions of the ANS?

Symp
Parasymp
Enteric

30

What is the transmitter used in somatic nerves?

ACh

31

What is the neurotransmitter used in the parasymp division of the ANS?

Ach

32

What is the neurotransmitter used in the symp division of the ANS?

NE

33

What is the significance of the fact that ANS fibers branch out after they synapse?

Can have multiple symptoms in each area

34

True or false: the eyes and the heart are connected through their parasymp innervation

True

35

What is meant by the term dual innervation?

That msot organs receive innervation from both the symp and para, but that they are not antagonistic

36

What are the exceptions to the dual innervation rule, and receive only sympathetic innervation? (6)

Hair follicles
Sweat glands
Liver
Adrenal glands
Kidneys
Blood vessles

37

What is the neurotransmitter that all somatic nerves release?

Ach

38

What is the neurotransmitter that all preganglionic nerves release?

Ach

39

Parasympathetic post-ganglionic fibers release what neurotransmitter?

Ach

40

Sympathetic post-ganglionic fibers release what types of neurotransmitters?

Epi/norepi
Dopamine

41

What is the neurotransmitter that the sympathetic division of the ANS that innervates sweat glands?

Ach

42

What division of the ANS releases neurotransmitters other that ACh?

postganglionic sympathetic

43

Why is the sweat gland's inervation weird?

Its symp innervation, but uses Ach

44

Symp ASN to cardiac smooth muscle, gland cells, and nerve terminals use what type of neurotransmitter?

NE

45

Symp ASN to renal vasculature and smooth muscle use what type of neurotransmitter?

Dopa

46

All parasympathetic neurons use what type of neurotransmitter?

ACh

47

Somatic nerves use which neurotransmitter?

ACh

48

What are the five steps to cholinergic transmission?

1. synthesis of neurotransmitter
2. storage
3. release
4. Action
5. Termination

49

How is acetylcholine synthesized? What is the pump and enzyme used?

1. Choline brought into nerve by choline transporter (CHT)
2. Acetyl-coa + choline = ACh via choline acetyltransferase (ChAT)

50

What is the group of drugs that can inhibit choline transporters?

Hemicholinums

51

How is ACh stored?

1. Vesicle associated transporter (VAT) stores ACh into vesicles

52

What is the class of drugs that inhibits the vesicle associated transporter (VAT) for ACh?

Vesamicol

53

What are the proteins that concentrate vesicles filled with Ach on the nerve terminal membrane?

VAMPs and SNAPs

54

What triggers the release of transmitter vesicles? What is the step that happens after that?

Influx of Ca, which binds to calmodulin, and interacts with the VAMP to trigger fusion

55

The acetylcholine vesicle release process is
blocked by botulinum toxin through what?

the enzymatic removal of two amino acids from one or more of
the fusion proteins

56

How is ACh's action terminated?

1. Degradation by Acetylcholine esterase
2. Reuptake by autoreceptors

57

What is the MOA of acetylcholinesterase inhibitors?

Increases [ACh]

58

What are the two types of cholinergic receptors?

Muscarinic
Nicotinic

59

What type of receptor is the muscarinic ACh receptors?

G protein

60

What type of receptor is the nicotinic ACh receptors?

Ion gated channel

61

What are the breakdow products of acetylcholinesterase?

Acetate and choline

62

What are the five subtypes of the muscarinic receptors?

M1-M5

63

What is the source of aqueous humor production in the eye?

Ciliary body epithelium

64

What is the route of aqueous humor formation?

From ciliary body epithelium, through pupil, to the canal of Schlemm

65

What is the muscarinic receptor located on the dilator (radial) muscle in the eye?

alpha 1

66

What is the muscarinic receptor located on the sphincter muscle in the eye? If it is activated, what is the result?

M3, constriction

67

What are the muscarinic receptors located on the ciliary muscle in the eye?

M3 and B2

68

What are the muscarinic receptors located on the ciliary epithelium in the eye? What is the effect if each one is activated?

Alpha 2, beta 1 and 2

Betas= production of aqueous humor

69

What is the function of the radial muscle of the eye?

Dilate the eye

70

If the M3 receptor on the ciliary muscle in the eye is activated, what is the effect on the muscle?

Contraction/nead accomodation

71

If the beta2 receptor on the ciliary muscle in the eye is activated, what is the effect on the muscle

Relaxation/far accomodation

72

What are the predominant muscarinic receptors in the heart? What is this responsive to? What are the protein that are downstream of this?

M2, which responds to ACh, and activates a Gi protein, which opens K channels

73

What is the effect that M2 receptors have on the SA node of the heart?

Decrease heart rate

74

What is the effect that M2 receptors have on the AV node of the heart?

Decrease conduction velocity

75

What is the effect that M2 receptors have on the Atrial muscle of the heart?

Decreases atrial contraction

76

What is the effect that M2 receptors have on the ventricular muscle of the heart?

Decrease ventricular contraction

77

What are the predominant muscarinic receptors in the bronchi and bronchioles? What is their effect?

M3, contraction/brochospasm

78

What are the predominant muscarinic receptors in the bronchiolar submucosal glands? What is their effect?

M3,
Secretion/narrow lumen

79

To treat asthma patients, would you want to inhibit or activate the muscarinic receptors?

Inhibit

80

What are the predominant muscarinic receptors in the stomach? What is their effect?

M3, motility

81

What are the predominant muscarinic receptors in glands? What is their effect?

M1- secretion

82

What are the predominant muscarinic receptors in the intestine? What is their effect?

M3 - diarrhea, involuntary defecation

83

The bladder wall is richly supplied with parasympathetic cholinergic nerve endings and
has abundant postganglionic cell bodies. What is the muscarinic receptor located here? What does this cause? (3)

M3

1.Contraction of the detrusor muscle
2.Relaxing the trigone
3. Inhibiting contraction of the sphincter

"all wet"

84

What are the three different vascular smooth muscle cell innervation?

Directly innervated
Coupled
Indirectly coupled

85

What are the two inputs to vascular cell muscle?

Nerves
Endothelial cell layer

86

What are the muscarinic receptors located in vessels? Where are they located?

M3, located on the smooth muscle, and on the endothelial cell surface

87

When the endothelium of a vessel is intact, activation of M3R on endothelial cells leads to the production of what? What does this cause?

endothelium-derived relaxing factors (EDRFs) = vasodilation

88

When the endothelium is damaged, activation of M3R on vascular smooth
muscle causes what? How?

vasoconstriction d/t the unopposed EDRFs

89

What is the MOA behind the muscarinic receptor in smooth muscle of the endothelium in vessels? (3)

Increase [Ca], binds to calmodulin, activates NOS = relaxation

90

What are the neurotransmitters on the smooth muscle cell side of vessels that activate the alpha 1 and P2x receptors, and cause muscle contraction?

NPY
NA
ATP

91

What are the neurotransmitters on the smooth muscle cell side of vessels that activate the P2Y receptors, and cause muscle contraction?

ATP
CGRP
SP

92

What are the neurotransmitters on the smooth muscle cell side of vessels that activate the CGRP receptors, and counteract muscle contraction?

ATP
CGRP
SP

93

What are the neurotransmitters on the endothelial cell surface that activate EDRF/NO to produce a relaxing effect?

Histamine
Vasopressin
Angiotension II

94

What happens if there is endothelial cell damage in vessels?

M3 receptor activates smooth muscle contraction

95

What is the dominant muscarinic receptor in sphincters? What does this cause? What is the one exception to this?

M3, causes relaxation except the lower esophageal sphincter

96

What is the dominant muscarinic receptor in glands? What does this cause?

M3, secretion
Salivation and lacrimation

97

M1 and M3 protein receptors activate what G protein? What pathway does this activate?

Gq, phospholipase C.. increases PKC

98

M2 protein receptors activate what G protein? What pathway does this activate?

Gi, inhibits adenylate cyclase... decreases PKA

99

Where are nicotinic receptors located?

On all autonomic ganglia

100

What is the nicotinic receptor in the adrenal medulla? What does this cause?

Nn, secretion of epi and norepi

101

What is the nicotinic receptor in autonomic ganglia? What does this cause?

Nn--stimulation but end effect depends on receptors of organ

102

What is the nicotinic receptor neuromuscular junctions? What does this cause?

Nm, causes stimulation

103

Are the Nn and Nm receptor identical?

No, but closely related

104

What is the precursor for catecholamines?

Tyrosine

105

What is the first step in the synthesis of catecholamines? Enzyme?

Conversion of tyrosine to DOPA by tyrosine hydroxylase

106

What is the chemical discussed in lecture that inhibits tyrosine hydroxylase (the first step in DOPA synthesis)?

Metyrosine

107

What is the final product in most catecholamine synthesizing neurons?

Norepi

108

In dopaminergic neurons, catecholamine synthesis terminates with what?

Dopamine

109

What is the enzyme that transports dopamine into vesicles?

Vesicular monoamine transporter (VMAT)

110

What is the drug that inhibits VMAT (the enzyme that transports dopamine into vesicles)?

Reserpine

111

How does release of dopamine-containing vesicles take place?

Same as in ACh cholinergic endings (VAMPs binding to SNAPs)

112

What is the only place in the body where norepi is converted into epi?

Adreanal medulla

113

What is the rate limiting step in dopamine synthesis?

Tyrosine hydroxylase

114

What is the food type that can increase tyramine synthesis, and thus cause an increase in norepi?

Fermented cheese

115

What is the MOA for reserpine lowering BP?

Inhibits smooth muscle contraction

116

What is the chemical that inhibits vesicle release in the catecholamine pathway?

Bretylium

117

What are the fates of NE when it is in the synapse?

1. Binding to receptor proteins
2. Diffusion
3. Reuptake by NE transporter (NET)
4. Reuptake by autoreceptors

118

What is the MOA of cocaine, and tricyclic antidepressants?

Blocks the NET, causing NE is stay in the synapse

119

What is the MOA of MAOIs?

Inhibits the enzyme monoamine oxidase, which would normally degrade NE

120

Why can MAOIs increase BP?

Increases NE, which may increase it in vascular signalling

121

All adrenergic receptors are what?

G protein-coupled receptors.

122

What are the three major MOA of adrenergic receptors?

Gs (increase adenylate cyclase)

Gi (decrease adenylate cyclase)

Gq (Increase phospholipase C)

123

What is the G protein in adrenergic β(1 and 2) and α2 receptor activation?

Gs

124

What is the G protein in adrenergic α2 receptor activation?

Gi

125

What are the receptors that activate the Gq protein?

H1, alpha1, V1, M1, M3

126

What are the receptors that activate the Gs protein?

Beta 1, beta 2, D1, H2, V2

127

What are the receptors that activate the Gi protein?

M2, Alpha2, D2

128

What are the receptors that activate the Nn and Nm proteins?

No second messenger--open Na channels

129

What are the 7 places that alpha 1 receptors are? What is the effect?

Eye (radial dialator muscle)
Arterioles (contract)
Veins (contract)
Bladder (urinary retention)
Penis
Liver (glycogenolysis)
Kidney (renin release)

For all, think symp

(Bleak VP)

130

What are the 3 places that alpha 2 receptors are? What are their effects their?

Prejunctional nerve terminal (lower transmitter release)

Platelets (aggregation)

Pancreas (decrease insulin)

131

What is the effect of alpha 1 receptor on the external bladder sphincter? Why do you pee your pants when afraid?

Contracts it.

Parasymp try to overtake symp

132

What are the two locations of Beta 1 receptors?

heart and kidney

133

What are the four areas of the heart that have beta 1 receptors? What does activation of each one do?

SA node (increase HR0

AV node (increase conduction velocity)

Atrial&vent muscle (increase)

His/purkinje (increase conduction velocity)

134

Where are Beta 2 receptors located?

Blood vessels
Uterus
Bronchioles
Skeletal muscle
Liver
Pancreas

135

What is the effect of beta 2 receptors on blood vessels?

Vasodilation

136

What is the effect of beta 2 receptors on blood the uterus?

Relaxation

137

What is the effect of beta 2 receptors on bronchioles?

Dilation

138

What is the effect of beta 2 receptors on skeletal muscle and the liver?

Glycogenolysis

139

What is the effect of beta 2 receptors on the pancreas?

Insulin secretion

140

What are the three locations of Dopaminergic receptors? What is their function there?

Renal
Mesenteric
Coronary vasculature

(vasodilation for all, causes increase in GFR)