ANS Flashcards
1
Q
What are the two components of the nervous system?
A
CNS and PNS
2
Q
The somatic and autonomic nervous system are a part of which division of the nervous system (CNS or PNS)?
A
PNS
3
Q
The final common pathway linking the central nervous
system to skeletal muscles is what?
A
Alpha motor neurons
4
Q
Efferent axons in the somatic nervous system synapse where?
A
on effector cells
5
Q
What are the final common pathways from the CNS to peripheral target organs?
A
Sympa and parasymp neurons
6
Q
Does the somatic system have ganglia?
A
no
7
Q
Do the sympatheic and parasymp nerves have ganglia?
A
yes
8
Q
How do presynaptic sympathetic neurons compare to postsynaptic side?
A
Short preganglionic
Long post
9
Q
Parasympathetic ganglia cells are clustered where?
A
within walls of visceral organs
10
Q
How do presynaptic PARAsympathetic neurons compare to postsynaptic side?
A
Long preganglionic
Short postganglionic
11
Q
Why is the adrenal gland a special case of innervation?
A
No post synaptic–just hormones released into the blood
12
Q
What are the two different types of stimuli that the ANS can have?
A
Excite or inhibit
13
Q
The somatic α motor neurons are (BLANK) in diameter and therefore allow (BLANK) conduction
A
The somatic α motor neurons are larger in diameter and therefore allow faster conduction
14
Q
Where are the cell bodies of the sympathetic division located?
A
In the intermediolateral columns of the spinal cord, in the thoraco-lumbar section
15
Q
What are the spinal levels of the sympathetic division?
A
T1-L3/4
16
Q
Axons for the preganglionic symp neurons exit the spinal cord and enter what structure?
A
White rami communicates
17
Q
Are most preganglionic symp neurons myelinated or unmyelinated?
A
Myelinated
18
Q
What are the three routes that sympathetic nerves take after leaving the spinal cord?
A
- To symp chain, where they synapse
- Through chain, and synapse in specialized ganglia
- Straight to organ (e.g. adrenal medulla)
19
Q
What are the two regions of the parasympathetic division?
A
- Cranial outflow
2. Sacral outflow
20
Q
Where parasympathetic nerves from the cranial division synapse?
A
Near the organ they innervate
21
Q
Where parasympathetic nerves from the sacral division synapse?
A
in a
group of scattered pelvic ganglia
22
Q
True or false: The pelvic ganglia carry both sympathetic and
parasympathetic fibers
A
True
23
Q
What are the two division of the enteric nervous system? Where are they located?
A
Myenteric (between muscular layers of gut tube)
Submucosal layer (beneath circular muscularis mucosae)
24
Q
What is the function of the myenteric plexus?
A
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)
