ANS Harvey Part 1 Flashcards
1
Q
What is sometimes referred to as the “visceral” nervous system control system involved in homeostasis
functions without conscious control - sometimes referred to as the “automatic” or “involuntary” nervous system a component of the peripheral nervous system
A
ANS (autonomic nervous system)
2
Q
The (blank) plays an important role in regulating virtually every organ system in our bodies.
A
autonomic(or involuntary) nervous system
3
Q
Furthermore, a large number of important drugs act by modifying the effects of the (blank) .
A
autonomic nervous system
4
Q
The ANS consists of (blank) neuron arranged in sequence followed by an effector cell (i.e. cardiac myocyte, smooth muscle cell, glandular cell)
A
two
5
Q
What are the two synaptic connections that the ANS makes?
A
includes two synaptic connections:
between first (preganglionic) and second (postganglionic) neurons
between postganglionic neuron and effector cell
6
Q
If you see a cell body in a sympathetic or parasympathetic fiber, is it a preganglionic fiber or a post?
A
it is post
7
Q
No ganglia associated with (blank) . Cell body is found in (blank) and axon projects directly to effector (skeletal muscle fiber)
A
somatic motor neurons
spinal chord
8
Q
(blank) are structures in which the cell bodies of sensory neurons reside. There are no (blank) connections in these ganglia.
A
Dorsal root ganglia
synaptic
9
Q
Autonomic ganglia contain cell bodies of postganglionic neurons but also are the sites where (blank) connections are made between preganglionic nerve terminals and postganglionic cell bodies/dendrites.
A
synaptic
10
Q
Synapses in autonomic ganglia are not necessarily simple (blank) .
A
1:1 relays
11
Q
ANS consists of sympathetic and parasympathetic components many organs and tissues receive input from (blank) components
A
both
12
Q
sympathetic and parasympathetic effects usually (blank) one another
A
oppose
13
Q
What tissue does not receive input from both systems, only receives it from the sympathetic?
Why?
A
skin, piloerector muscles, sweat glands, most blood vessels
Cuz parasympathetic does not affect blood vessels (except for erections)
14
Q
sympathetic innervation of the (blank) is an important exception to the two neuron rule
A
adrenal medulla
15
Q
sympathetic preganglionic neurons synapse with (blank) in the adrenal medula, not postglanglionic neurons
A
chromaffin cells
16
Q
chromaffin cells release “neurotransmitter” (blank) into blood stream which carries it to effector organs – epinephrine acting more like a hormone
chromoaffin cells- act as postganglion
A
epinephrine
17
Q
Where will you find acetylcholine?
A
- at synapses between ALL pre and postganglionic neurons in all autonomic ganglia
- Synapses b/w parasympathetic postganglionic neurons and their effectors
- at the neuromuscular junction in skeletal muscle (somatic nervous system)
18
Q
What do you call neurons that release acetylcholine?
A
cholinergic
19
Q
What is the neurotransmitter (typically) b/w the sympathetic postganglionic fiber and the effector organ?
A
norepinephrine
20
Q
What are the 2 important exceptions when norepinephrine is not used at the second synapse for sympathetics?
A
1) B/w postganglionic neurons and sweat glands is acetylcholine
2) Chromaffin cells in the adrenal medulla release epinephrine and norepinephrine
21
Q
What do you call neurons that release norepinephrine and/or epinephrine?
A
adrenergic receptors
22
Q
Sympathetic postganglionic responses mostly mediated by (blank)
A
norepinephrine
23
Q
(blank) mediate autonomic responses associated with the release of acetylcholine
A
cholinergic receptors
24
Q
What are the two types of cholinergic receptors?
A
nicotinic receptors and muscarine receptors
25
nicotinic receptors are ligand (blank)
gated ion channels
26
(blank) is the primary receptor at all autonomic ganglia (parasympathetic and sympathetic)
nicotinic receptors
27
What is the postsynaptic receptor on skeletal muscle at neuromuscular junctions?
nicotinic receptors
28
Ganglion (Nn) and Muscle (Nm) receptors are both nicotinic receptors but are distinct (blank) of nictinic receptors
subtypes
29
At low doses nicotine (blanks) and at high doses it (blank) both ganglionic and muscle nicotinic receptors.
stimulates
| blocks
30
(blank) blocks both ganglionic and muscle receptors
curarae
31
Muscarinic receptors are a type of (blank) receptor.
| Is it a G coupled receptor or a ligand ion gated channel?
Cholinergic receptors
| G coupled receptor
32
What do muscarinic receptors do?
mediate parasympathetic end organ/tissue responses
33
How many different subtypes of mucarinic receptors are there?
5
34
What are muscarinic receptors activated by?
| Blocked by?
mucarine
| atropine
35
Where do you typically find nicotinic receptors?
Nn-postganglionic neuron, CNS and they open non-selective cation channels (depolarization)
Nm- skeletal muscles end plates and they open non-selective cation channels (depolarization)
36
Where do you find M1 (muscarinic) receptors?
smooth muscle, exocrine glands,
| CNS neurons
37
What are the effects of ligand binding of M1?
Formation of IP3 (increase intracellular Ca2+) and DAG (activate PKC)
38
Where do you find M2 (muscarinic) receptors?
cardiac muscle, CNS neurons
39
What are the effects of ligand binding of M2?
Activate K+ channels (hyperpolarization), inhibit adenylyl cyclase (decrease cAMP)
40
What are the effects of ligand binding of M3?
Formation of IP3 (increase intracellular Ca2+), DAG (activate PKC)
41
Where do you find M3 (muscarinic) receptors?
smooth muscle, vascular endothelium, exocrine glands, CNS neurons
42
Where do you find M4 (muscarinic) receptors?
CNS neurons
43
What are the effects of ligand binding of M4?
Activate K+ channels (hyperpolarization), inhibit adenylyl cyclase (decrease cAMP)
44
Where do you find M5 (muscarinic) receptors?
vascular endothelium, CNS neurons
45
What are the effects of ligand binding of M5?
Formation of IP3 (increase intracellular Ca2+), DAG (activate PKC)
46
Knowing the function of cholinergic receptors helps determine the effect a (blank) will have.
drug
47
What mediate autonomic responses due to release of norepinephrine and epinephrine
adrenergic receptors
48
Are adrenergic receptors ion-ligated receptors or G protein coupled receptors?
G-protein
49
What are 2 major types of Adreneregic receptors?
Alpha and beta
50
Where will you find alpha 1 adrenergic receptors and what do they do?
- located in smooth muscle and glandular tissue
| - causes smooth muscle contraction
51
Where will you find alpha 2 receptors and what do they do?
located primarily on presynaptic nerve terminals
| - inhibit the release of norepinephrine from postganglionic sympathetic neurons
52
Does alpha 1 or alpha 2 function in feedback inhibition?
alpha 2
53
How many Beta adrenergic receptors are there and hat are there?
3
| 1,2,3
54
Where will you find beta 1 receptors and what do they do?
- located primarily in the heart
| - increase heart rate and contractility
55
Where will you find beta 2 receptors and what do they do?
- located primarily in smooth muscle
| - cause smooth muscle relaxation
56
Where will you find beta 3 receptors and what do they do?
- located primarily in adipocytes
| - cause lipolysis
57
(blank) has a higher affinity for alpha 1 then for b2 which is why we more commonly see smooth muscle contraction rather than relaxation.
Norepinephrin
58
What is the typical location of alpha 1 and what are the effects of ligands binding to it?
```
smooth muscle (blood vessels, eye, gut, bladder)
Formation of IP3 (increase intracellular Ca2+), DAG (activate PKC)
```
59
What is the typical location of alpha 2 and what are the effects of ligands binding to it?
presynaptic nerve terminals, smooth muscle (blood vessels)
| inhibition of neuronal Ca2+ channels; inhibition of adenylyl cyclase (decrease cAMP)
60
What is the typical location of Beta 1 and what are the effects of ligands binding to it?
cardiac myocytes, juxtaglomerular cells (kidney)
| Stimulation of adenylyl cyclase, increased cAMP
61
What is the typical location of Beta 2 and what are the effects of ligands binding to it?
```
smooth muscle (airways, blood vessels), ciliary body epithelium (eye), cardiac muscle
Stimulation of adenylyl cyclase and increased cAMP
```
62
What is the typical location of Beta 3 and what are the effects of ligands binding to it?
adipocytes
| Stimulation of adenylyl cyclase and increased cAMP
63
Summarize the where you will find specific receptors
cholinergic receptors in autonomic ganglia are nicotinic
cholinergic receptors at autonomic end organs are muscarinic
α and β adrenergic receptors have overlapping but distinct distribution patterns in different autonomically regulated end-organs/tissues
pharmacologic selectivity is relative – no drug is a “magic bullet”
64
Where do you see an all or nothing response with neurons?
somatic motor neurons and the neuromuscular junction (NMJ)
65
What allows for the intergration of neural input and modulation of end organ responses?
divergence and convergence
66
Where is divergence more common?
sympathetic where it has a wide range response
67
Where is convergence more common?
parasympathetic where it gives off a more intense or integrating response
68
The (blank) is a region of muscular membrane that contains high concentration of ACh receptors.
motor end plate
69
What does this describe:
transmitter is released at the presynaptic nerve terminal
postsynaptic receptors are found only at the end plate
End plate contains Nicotinic and Ach receptors
innervation is 1:1
responses are rapid and all-or-none
A somatic motor neuron synapsing at a neuromuscular junction
70
Where is the only place that release Ach Nicotinic receptors in a muscle fiber AND is the place that the neuron synapses?
end plate
71
Do autonomic synapses release all at one time like somatic motor neurons do at end plates?
no they release from varicosities (little swelling throughout the axon) and distribute the neurotransmitter throughout the entire cell
72
Do autonomic synapses have a fast or slow respons?
slow
73
How can a postsynaptic response vary?
time response and whether they are inhibitory or excitatory
74
What type of receptor causes depolarization and is always excitatory?
nicotinic
75
Are muscurain receptors excitatory and are they fast?
sometimes, and they are slowish
76
Many end organs receive both sympathetic and parasympathetic innervation. In those situations, the regulatory effects are usually (blank).
antagonistic
77
Sympathetic and parasympathetic stimulation can produce antagonistic responses by eliciting the opposite effect on a (blank) (e.g., the heart) or by eliciting the same type of response on (blank) (e.g., the eye).
common cell type
| different cell types
78
Sympathetic stimulation is associated with a (blank)
“fight or flight” response
79
Parasympathetic stimulation is associated with a (blank) response.
“rest or digest”
80
EXCEPTIONS TO THE RULES
| some tissues only receive sympathetic innervation.. What are some examples?
(e.g., most blood vessels, sweat glands, hair follicles)
81
EXCEPTIONS TO THE RULES
some tissues receive both sympathetic and parasympathetic innervation, but the responses they produce are complimentary. What is an example?
(e.g., salivary glands)
82
```
Sympathetic Fight or Flight response makes what happen to these things?
Eye:
Heart:
Blood vessels:
GI:
Bladder:
Skeletal Muscle:
```
Pupil open; distant focus
Increased rate & force of contraction
Constriction
Decreased motility, sphincters constricted
Bladder wall relaxed, internal sphincter contracted
Stimulate glycogenolysis
83
```
Parasympathetic "rest and digest" response makes what happen to these things?
Eye:
Heart:
GI:
Bladder:
```
Small diameter pupil; near focus
slower heart rate-decreased cardiac output
enhance motility, sphincters relaxed-facilitates digestion
bladder wall contracted, internal sphincter relaxed
84
Where is the SA node located?
upper border of the right atrium
85
The SA node response is mediated by what neurotransmitters?
Norepinephrine and acetocholine
86
SA NODE
| Sympathetic activation of Beta1 adrenergic receptors has a (blank) effect.
positive chronotropic effect (increases heart rate)
87
SA NODE
| Parasympathetic activation of M2 muscarinic receptors has a (blank) effect.
negative chronotropic effect (decreases heart rate)
88
Where is the AV node located?
close to the tricupsid valve (b/n right atrium and right ventricle)
89
AV NODE
| Sympathetic activation of β1 adrenergic receptors has a (blank) effect
positive dromotropic effect (increases conduction velocity)
90
AV NODE
| Parasympathetic activation of M2 muscarinic receptors has a (blank) effect
negative dromotropic effect (decreases conduction velocity)
91
Ventricular Muscle
| Sympathetic activation of β1 adrenergic receptors has a (blank) effect
positive inotropic effect (increases contractility)
92
Ventricular Muscle
Parasympathetic activation of M2 muscarinic receptors (blank) responses. In the absence of sympathetic tone, parasympathetic activation has little or no effect on the ventricles.
antagonizes sympathetic
93
(blank) response has to be stimulated in order for parasympathetic to have an effect on ventricular muscle.
Can parasympathetic activation of M2 muscarinic receptors still have an affect on cardiac output?
Why?
Sympathetic
yes
due to the affect on velocity of blood flow not heart contractility
94
How are blood vessels affected by the ANS?
Sympathetic activation
α1 adrenergic receptors cause vascular smooth muscle contraction and constriction of blood vessels.
β2 adrenergic receptors cause relaxation of vascular smooth muscle and dilation of blood vessels.
95
(blank) activation has little or no effect on most blood vessels. Exceptions include blood vessels of the face, tongue, genitals and urinary tract, where parasympathetic stimulation causes relaxation of the vascular smooth muscle and vasodilation.
Parasympathetic
96
How is the adrenal medulla affected by the ANS?
Sympathetic stimulation by preganglionic neurons that synapse directly with chromaffin cells in the adrenal medulla causes the release of epinephrine and norepinephrine into the circulation.
Parasympathetic stimulation has no effect on the adrenal medulla.
97
How is the lung affected by the ANS?
Sympathetic activation of β2 adrenergic receptors causes relaxation of bronchial smooth muscle and dilation of the airways.
Parasympathetic activation of muscarinic receptors causes
contraction of bronchial smooth muscle and constriction of the airways
stimulation of secretion of bronchial glands
98
How is the eye affected by the Alpha 1 adrenergic receptor and muscarinic receptors?
Sympathetic activation of α1 adrenergic receptors contracts iris radial muscles, dilating the pupil (mydriasis).
Parasympathetic activation of muscarinic receptors contracts iris circular muscles, constricting the pupil (miosis).
(Systems act on different muscles (still opposing affects though)
99
How is the eye affected by beta 2 adrenergic receptors?
Sympathetic activation of β2 adrenergic receptors
--relaxes ciliary muscles allowing the lens to focus on far objects.
--stimulates ciliary epithelium secretion of aqueous humor
100
What disease do you want to block the b2 receptors (stop secretion of aqueous humor), or activate parasympathetic receptors
Glaucoma
101
How is the eye affected by the parasympathetic activation of muscarinic receptors?
contracts ciliary muscles
causing the lens to focus on near objects.
increasing outflow of aqueous humor through trabecular meshwork into canal of Schlemm
102
How are the stomach and intestines affected by the ANS?
```
Sympathetic activation of
β2 and α2 receptors decreases motility and tone
α receptors contracts sphincters
Parasympathetic activation of muscarinic receptors
increases gut motility and tone
relaxes sphincters
stimulates glandular secretion
```
103
Autonomic regulation of the gut can involve (blank)
enteric neurons
104
How is the Urinary Bladder affected by the ANS?
Sympathetic activation (promotes filling)
α adrenergic receptors contract the internal sphincter muscle
β adrenergic receptors relax the detrusor muscle
Parasympathetic activation (promotes voiding)
contracts the detrusor muscle
relaxes the internal sphincter
105
How are the Salivary Glands affected by the ANS?
Sympathetic activation
α receptors cause a weak increase in potassium and water secretion
β receptors cause a weak increase in amylase secretion
Parasympathetic activation of muscarinic receptors causes a pronounced increase in potassium and water secretion.
(Both systems increase salivary secretions (exception to opposing affects)
106
How is the skin affected by the ANS?
Sympathetic activation
α receptors contract pilomotor muscles
muscarinic receptor activation by acetylcholine released from postganglionic sympathetic fibers causes generalized sweating
The parasympathetic nervous system has little or no direct effect on responses in the skin.
***Sympathetic cholinergic (exception, usually adrenergic)- in sweating ****
107
What is the predominant system of the ANS in the blood vessels. What receptor type?
sympathetic, adrenergic
108
What is the predominant system of the ANS in the heart, What receptor type?
parasympathetic, cholinergic
109
What is the predominant system of the ANS in the eye (iris),What receptor type?
parasympathetic, cholineric
110
What is the predominant system of the ANS in the eye (ciliary muscle), What receptor type?
parasympathetic cholinergic
111
What is the predominant system of the ANS in the gut, What receptor type?
parasympathetic cholinergic
112
What is the predominant system of the ANS in the urinary bladder , What receptor type?
parasympathetic cholinergic
113
What is the predominant system of the ANS in the salivary glands, What receptor type?
parasympathetic cholinergic
114
What is the predominant system of the ANS in the sweat glands? What receptor type?
sympathetic cholinergic
115
cholinergic receptors in autonomic ganglia are (blank)
nicotinic
116
cholinergic receptors at autonomic end organs are (blank)
muscarinic
117
(blank) receptors have overlapping but distinct distribution patterns in different autonomically regulated end-organs/tissues
α and β adrenergic
118
pharmacologic selectivity is (blank) – no drug is a “magic bullet”
relative
119
What is the parasympathetic (predominant) adrengergic effect of ganglionic blockade in the heart?
tachycardia
120
What is the parasympathetic (predominant) adrengergic effect of ganglionic blockade in the iris?
Dilation of the pupil
121
What is the parasympathetic (predominant) adrengergic effect of ganglionic blockade in the ciliary muscle?
Paralysis of accommodation
122
What is the parasympathetic (predominant) adrengergic effect of ganglionic blockade in the GI tract?
Reduced tone & motility
123
What is the parasympathetic (predominant) adrengergic effect of ganglionic blockade in the urinary bladder?
Urinary retention
124
What is the sympathetic (predominant) adrengergic effect of ganglionic blockade in the sweat glands?
Absence of sweating
