L7: Autonomic Nervous System Flashcards
1
Q
the autonomic and somatic nervous systems are divisions of the…
A
peripheral nervous system
2
Q
the peripheral nervous system is divided into the…
A
autonomic NS
somatic NS
3
Q
the autonomic nervous system is divided into the…
A
sympathetic
parasympathetic
enteric
4
Q
this nervous system controls skeletal muscles
A
somatic
5
Q
aka voluntary nervous system
A
somatic nervous system
6
Q
aka involuntary nervous system
A
autonomic nervous system
7
Q
smooth muscles, cardiac muscles, and glands are all controlled by this nervous system
A
autonomic nervous system
8
Q
aka visceral involuntary sensory and motor system
A
autonomic nervous system
9
Q
how do somatic and autonomic nervous systems differ with regard to number of neurons between CNS and effector organ
A
somatic - 1 neuron between CNS and effector
autonomic - 2 neuron between CNS and effector
10
Q
how do somatic and autonomic nervous systems differ with regard to excitatory vs inhibitory stimuli
A
somatic - stimulates contraction only
autonomic - can be excitatory or inhibitory
11
Q
dysautonomia
A
disfunction of the autonomic nervous system, unable to maintain homeostasis
12
Q
disfunction of this nervous system results in problems maintaining homeostasis
A
autonomic nervous system
13
Q
the autonomic nervous system is under control of the …
A
CNS
hypothalamus & limbic system
14
Q
the branch of the autonomic nervous system that is not covered in detail in this class
A
enteric
15
Q
what are the two main divisions of the autonomic nervous system
A
sympathetic
parasympathetic
16
Q
organs influenced by the autonomic nervous system are usually innervated by the __ division
A
sympathetic & parasympathetic (usually dual innervation)
17
Q
dual sympathetic & parasympathetic innervation is generally described as __
A
antagonistic
18
Q
fight or flight nervous system
A
sympathetic
19
Q
rest/digest nervous system
A
parasympathetic
20
Q
where are the cell bodies of sympathetic preganglionic neurons located?
A
vertebrae T1 to L3
21
Q
do sympathetic postganglionic neurons have long or short projections to their targets, compared to autonomic postganglionic neurons
A
long
ganglia are paravertebral or prevertebral
22
Q
paravertebral means
A
alongside the vertebrae
23
Q
prevertebral means
A
ventral to vertebrae
24
Q
what is the sympathetic chain
A
paravertebral bundles of sympathetic ganglia
25
where are the cell bodies of parasympathetic preganglionic neurons located?
midbrain, pons, medulla
or
sacral spinal cord S2-S4
26
__ axons project to ganglia very near or inside effector organs
parasympathetic
27
relative to sympathetic, parasympathetic postganglionic neurons have __ projections to their targets
short
28
while sympathetic preganglionic neurons exit the spinal cord the sympathetic trunk extends along which portion of the spinal cord
the entire length of the spinal cord
29
T/F one preganglionic sympathetic neuron synapses with many postganglionic fibers
true
30
what is the average ratio of pre to post ganglionic sympathetic fibers
1:10
31
which division of the autonomic nervous system has preganglionic nerves associated with cranial nerves
parasympathetic
32
this cranial nerve parasympathetically innervates most viscera
vagus X
33
what is the average ratio of pre to post ganglionic parasympathetic fibers
1:3 but often 1:1
34
which division of the autonomic nervous system has a greater pre to post ganglionic fiber ratio?
sympathetic (1:10)
| vs parasympathetic 1:3
35
most organs have dual innervation except sweat glands, adrenal medulla, and peripheral blood vessels, which are innervated only by...
the sympathetic division
36
these nerves travel from CNS to effectors
efferent fibers
37
these nerves travel from effectors to CNS
afferent fibers
38
the two most important neurotransmitters are...
ACh and NE
39
the neurotransmitter acting at synapses between pre and post ganglionic neurons in both the sympathetic and parasympathetic nervous systems is...
ACh
40
neurotransmitter at sympathetic ganglia
ACh
41
neurotransmitter at parasympathetic ganglia
ACh
42
list the neurotransmitters and NT receptors that occur in autonomic nervous system ganglion
ACh only
| N2 (not N1)
43
cholinergic NT receptors bind __
ACh
44
adrenergic NT receptors bind __
NE and E
45
with regard to neurotransmitters, what are agonists vs antagonists
agonists - mimic neurotransmitter receptor binding and effect
antagonists - bind receptor and inhibit agonists
46
2 types of ACh (cholinergic) receptors
- nicotinic (N1 and N2)
| - muscarinic
47
a nicotinic receptor bind this NT
ACh (cholinergic)
48
a muscarinic receptor bind this NT
ACh (cholinergic)
49
how many types of nicotinic receptors
2 (N1 & N2)
50
curare blocks this NT receptor
N1 cholinergic receptor (skeletal muscle)
51
hexamethonium blocks this NT receptor
N2 cholinergic receptor (autonomic ganglia)
52
N1 receptors
bind...
located...
blocked by...
ACh
skeletal muscle
curare
53
T/F N1 receptors can be found in autonomic ganglia
false
N1 is found on skeletal muscle
N2 is ACh receptor in ganglia
54
N2 receptors:
bind...
located...
blocked by...
ACh
autonomic ganglia
hexamethonium
55
T/F N1 receptors can be found in the autonomic nervous system
false - found in somatic nervous system on skeletal muscle
56
the cholinergic receptor on skeletal muscle
N1
57
the cholinergic receptor(s) in the somatic nervous system
N1 (on skeletal muscle)
58
the cholinergic receptor(s) in the autonomic nervous system
N2 (ganglia)
| M (effectors)
59
M receptors
bind...
located...
blocked by...
ACh
effector organs (smo&card muscle, glands)
atropine
60
atropine blocks this NT receptor
M (cholinergic effector organs)
61
outline the NE receptors (location, function)
all occur in the sympathetic effector synapse
α1 - contraction of smomusc & blood ves
α2 - autoreceptor on adrenergic presynaptic membranes to downregulate NE release
β1 - inc HR, heart contraction force
β2 - relax GI smomusc & some vascular
62
where are adrenergic NT receptors usually found
sympathetic effector synapses
| smomusc, cardiac, GI
63
how does the adrenal medulla interact with the autonomic nervous system?
contains sympathetic cholinergic receptors (N2) and releases NE and E into blood in a ~20/80 ratio
64
what is/are the most common somatic NTs and receptors
-motor neuron releases ACh to N1 receptors on skeletal muscle
CNS---------------------------
65
what is/are the most common sympathetic NTs and receptors
--
66
what is/are the most common parasympathetic NTs and receptors
--<(smom, cardm, glands)
67
N1
N2
M
cholinergic receptors blocked by...
curare
hexamethonium
atropine
68
curare
hexamethonium
atropine
block which NT receptors
N1
N2
M
69
the adrenal gland secretes NE and E in what proportions
20% to 80%
70
NTs other than ACh and NE include:
```
ATP/adenosine (GI)
serotonin
dopamine
GABA
NO (dilation)
```
71
when a circular smooth muscle dilates, is it contracting or relaxing?
relaxing
72
is the general effector responses to the following NTs excitatory or inhibitory?
- ACh
- NE
- E
impossible to tell: nervous system, NT, receptor, and effector all play a role in specificity of effector response
73
is the general effector responses to the following NT receptors excitatory or inhibitory?
- N1
- N2
- M
- α1 adrenergic
- α2 adrenergic
- β1 adrenergic
- β2 adrenergic
impossible to tell: nervous system, NT, receptor, and effector all play a role in specificity of response. BUT, if you have to guess:
- N1 - stimulates muscle contraction
- N2 - stimulates post-ganglionic autonomic nerve
- M - ... hard to tell
- α1 adrenergic - stims vas&GI constrict
- α2 adrenergic - ..decreases NE singal...
- β1 adrenergic - stims HR & force
- β2 adrenergic - relaxes GI
74
T/F multiple kinds of NTs and receptors can be present on a given effector organ
true
75
β adrenergic stimulation of the heart leads to...
increased HR and stronger force of contractility
76
β adrenergic stimulation of the GI tract elads to..
relaxation/dilation
77
what does it mean to say that usually the two divisions of the ANS are activated "reciprocally" ?
increase activity of one
decrease activity of the other
generally
78
dopamine β hydroxylase (DβH) converts dopamine into this NT in the process of NT synthesis
NE
79
dopamine is converted to NE by this enzyme in the process of NE synthesis
dopamine β hydroxylase DβH
80
3 precursers in NE synthesis
tyrosine....dopa....dopamine
81
what are "varicosities" in the context of neurotransmission
swellings in an axon (like beads on a string) prior to the axon terminus that function in NE synthesis and release to an effector in response to an action potential while being modulated by a variety of other NT input at NT receptors
(usually sympathetic, adrenergic axons, sometimes parasympathetic)
82
in what 3 ways is NE cleared from a sympathetic synaptic cleft?
- diffusion into capillaries
- reuptake (70%) by Na+ coupled symport and recycled to vesicles or broken down my monoamine oxidase (MAO) in mitochondria
- extraneuronal uptake (by the effector cell for instance) and degradation by MAO
83
what enzyme is involved in NE clearance from an adrenergic synapse?
monoamine oxidase MAO
| degrades NE in pre-synaptic neuron or post-synaptic cell
84
how is neurotransmission accomplished in an adrenergic nerve?
through varicosities, swellings in the axon (like beads on a string) prior to the axon terminus that function in NE synthesis and release to an effector in response to an action potential while being modulated by a variety of other NT input at NT receptors
(usually sympathetic, sometimes parasympathetic)
85
T/F adrenergic nerve varicosities are usually in the sympathetic nervous sysem
true.. though they can be found in parasympathetic less frequently
86
what is the advantage of neurotransmission through varicosities?
can control multiple effectors with one neuron
87
do the following occur more frequently through varicosities or single boutons?
- sympathetic neurotransmission
- parasympathetic neurotransmission
sympathetic - varicosities
parasympathetic - single bouton
(though both are possible in each case)
88
how does degradation of NE by MAO differ from degradation of ACh by ACh-E?
- MAO acts in mitochondria after NE has been uptaken into pre or post-synaptic cell
- ACh-E acts in the synaptic cleft, either free floating or embedded in post-synaptic membrane
89
do the following occur more frequently through varicosities or single boutons?
- ACh neurotransmission
- NE neurotransmission
ACh - single bouton
| NE - varicosities
90
T/F autonomic regulation of organ function is usually modulatory and not initiatory
true - e.g. the heart pumps through autogenic ability, but autonomic input modulates
91
in neurotransmission, what is a "tonic discharge"
a variable but omnipresent discharge of action potentials
92
T/F autonomic neural input can affect individually or in concert
true
| concert example - fight or flight decrease of blood flow to viscera and increase of blood flow to skeletal muscles
93
if the ratio of pre to post ganglionic neurons is 1:200, you expect the ganglion to be part of which nervous system
sympathetic (greater pre vs post)
94
a number of preganglionic neurons of this nervous system exit the brain stem through cranial nerves III, VII, IX and X (vagus)
parasympathetic
95
T/F parasympathetic preganglionic neurons that exit the brain stem through cranial nerves III, VII, and IX and project to ganglia in the viscera
false
| parasympathetic neurons in cranial nerves III, VII, and IX project to the ciliary, submaxillary, and otic ganglia
96
T/F parasympathetic preganglionic neurons that exit the brain stem through cranial nerve X project to ganglia in the ciliary, submaxillary, and otic ganglia
false
| parasympathetic neurons in the X (vagus) project to visceral ganglia
97
T/F parasympathetic preganglionic neurons that exit the brain stem through cranial nerves III, VII, and IX and project to ganglia in the head and face
true
| parasympathetic neurons in cranial nerves III, VII, and IX project to the ciliary, submaxillary, and otic ganglia
98
T/F acetylcholine is stored and liberated by clear vesicles at parasympathetic nerve terminals
true
99
T/F aorepinephrine interaction with β receptors in the heart leads to excitation (an increase in rate and force of contraction)
true
100
T/F alpha adrenergic receptors, as a general rule, are associated with excitation by sympathetic nerves
true
101
T/F aiscera commonly have a dual innervation of parasympathetic and sympathetic nerves
true
102
T/F during an IPSP, recovery to resting membrane potential is achieved by the closing of the ligand-gated K+ or Cl- channels after neurotransmitter dissociates from the channel
true
103
T/F during an IPSP, ligand-gated K+ or Cl- channels opens, allowing an efflux of Cl- or influx of K+
false
efflux of K+
...very little flux of Cl-
104
how does d-tubocurarine affect neurotransmission
blocks ACh receptors
105
T/F the origins of some of the parasympathetic preganglionic neurons are in the X (vagus) cranial nerve
true
| at least they exit the CNS with the vagus nerve... origins really in the brain stem (midbrain, pons, medulla)
106
where do sacral parasympathetic preganglionic neurons go?
project to pelvic ganglion, with innervates colon, bladder, and genitalia
107
where do cranial parasympathetic preganglionic neurons project to?
where do sacral parasympathetic preganglionic neurons project to?
cranial - to cilliary, submaxillary, otic, and visceral ganglia
sacral - to pelvic ganglion -- and postganglionic nerves innervate colon, bladder, genetalia
108
T/F the transmitter released at preganglionic endings is acetylcholine
true
109
T/F the transmitter released at postganglionic endings acts on cholinergic muscarinic receptors
true
110
T/F the cell bodies of postganglionic neurons are generally located close to the organ innervated by their fibers
true
111
T/F β adrenergic receptors are generally associated with post ganglionic sympathetic nerve fibers
true - TECHNICALLY, they are associated with post ganglionic sympathetic effectors BUT, if this comes up in a true/false scenario on the test, it is probably true
112
T/F norepinephrine is synthesized from the amino acid tyrosine
true
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