Unit 2 - ANS A&P Flashcards
1
Q
makes up the CNS
A
- spinal cord
- medulla oblongata
- pons
- midbrain
- thalamus
- cerebral hemisphere
2
Q
included in cerebral hemisphere
A
- cerebral cortex
- subcortical white matter
- basal nuclei
3
Q
peripheral nervous system consists of:
A
spinal and cranial nerves (except CN2) present outside CNS
4
Q
ultimate responsibility of ANS
A
ensure physiologic integrity of cells , tissues ,and organs througout the entire body despite challenges from external environment
5
Q
ANS division that accounts for miosis and eye accommodation
A
PNS
6
Q
3 divisions of the ANS
A
- Sympathetic
- Parasympathetic
- Enteric divisions
7
Q
which anatomic part of the nervous system is surrounded and covered by meninges?
A
central nervous system
8
Q
which type of muscle does NOT receive ANS signals?
A
skeletal
9
Q
ANS division responsible for artery tone
A
SNS
10
Q
CV effects of SNS stimulation
A
- increased cardiac force, rate, conduction, excitability
- constriction and dilation of coronary arterioles
11
Q
pulmonary effects of PNS
A
bronchial smooth muscle contraction
12
Q
pulmonary effects of SNS stimulation
A
relaxation of bronchial smooth muscle
13
Q
eye effects of SNS stimulation
A
- mydriasis (pupil dilation)
- ciliary muscle relaxes (far vision)
14
Q
peripheral neurotransmitters of autonomic efferents
A
- ACh
- NE
- Epi
15
Q
peripheral NT of somatomotor efferents
A
ACh
16
Q
target organ(s) of somatomotor efferents
A
skeletal muscle
17
Q
nerve fiber classification of preganglionic autonomic efferents
A
lightly myelinated B fibers
18
Q
nerve fiber classfication of postganglionic autonomic efferents
A
nonmyelinated c fibers
19
Q
nerve fiber classification of somatomotor efferents
A
heavily myelinated A-alpha fiber
moderately myelinated A-gamma fibers
20
Q
control system of autonomic efferents
A
- primarily unconscious, involuntary control
- independent with hormonal control
21
Q
control system of somatomotor efferents
A
- primarily conscious, voluntary control
- unrelated to hormonal control
22
Q
neuron routes involved from spinal cord to target in somatic efferent pathways
A
1
23
Q
neuron routes involved from spinal cord to target in ANS efferent pathways
A
2
24
Q
schema for anatomic organization of ANS
A
origin → route to relay → relay → distribution → effector (target)
25
2 synonyms for efferent
motor, outflow
26
3 structures that comprise brainstem
- medulla
- pons
- midbrain
(mesencephalon)
27
2 synonyms for afferent
sensory, inflow
28
pathway assoc. with short preganglionic and long postganglionic fibers
SNS efferent pathways
29
SNS origin
preganglionic nerve cell body (soma)
30
characteristic feature of ANS
its efferents emerge as myelinated fibers from spinal cord or brain (CNS), are interrupted in course by synapse in a peripheral ganglion, and are then relayed for distribution as fine, nonmyelinated fibers to their effectors
31
nerve fiber classification of preganglionic neurons
lightly myelinated B fibers
32
nerve fiber classification of postganglionic neurons
unmyelinated C fibers
33
nerve fiber classification of A-alpha motor neurons
heavily myelinated, large fibers
34
nerve fiber classification of A-gamma motor neurons neurons
modestly myelinated, thinner fibers
35
where do sympathetic preganglionic neurons arise
thoracolumbar region
T1-L2
36
where are cell bodies of preganglionic sympathetic fibers located
lateral hord of spinal cord grey matter, specifically within intermediate (IML) nucleus
37
where does the IML lie
Rexed's lamina 7
38
where do parasympathetic preganglionic neurons travel
CN 3, 7, 9, 10 and sacral roots S2-S4
39
which division of the ANS is called the craniosacral system
parasympathetic
40
origin of the somatomotor division
ventral horn of the spinal cord
41
location of cell bodies of alpha and gamma motor neurons
Rexed's laminae 8 and 9
42
where do axons of preganglionic SNS neurons leave the spinal cord
segmental level at which their cell bodies are located
43
what forms the white rami
preganglionic symapthetic axons exiting from ventral root
44
why are white rami white
preganglionic fibers are lightly myelinated B fibers and myelin imparts a white color
45
why are grey rami grey
axons are nonmyelinated - these areas contain nerve cell bodies, which are grey
46
where do white rami exist and why
only at T1-L3, where all preganglionic SNS fibers originate from
47
what is a nerve plexus
network of afferent and efferent nerve fibers from different spinal nerves
48
somatic nerve plexuses
- cervical
- brachial
- lumbar
- sacral
49
visceral nerve plexuses
- cardiac
- abdominal aortic
- hypogastric
50
where are spinal levels gray rami found
all spinal cord levels
51
reflex characterized by increased HR in response to increased right atrial volume
example
Bainbridge
ex- autotransfusion during childbirth
52
enzyme that deactivates cAMP
phosphodiasterase
53
preganglionic fibers in SNS vs PNS
PNS
- preganglionic: long, myelinated, B-fiber, releases ACh
- postganglionic: short, unmyelinated, C-fiber, releases ACh
SNS
- pre: short, myelinated, B-fiber, releases ACh
- post: long, unmyelinated, C-fiber, releases NE
54
origin of efferent SNS pathways
T1-L3
cell bodies arise from IML region of spinal cord (rexed's lamina 7)
55
where do efferent SNS fibers exit
ventral nerve roots
56
where do efferent SNS preganglionic fibers synapse with postganglionic fibers
in paired sympathetic ganglia (mass effect)
57
origin of efferent PNS pathways
CN 3, 7, 9, 10
S2-S4
58
where do preganglionic fibers synapse with postganglionic fibers in craniosacral division
near or in each effector organ (precise control of each organ)
59
innervation of adrenal medulla
no postganglionic innervation
preganglionic axon takes a straight shot to adrenal medulla
60
sympathetic chain ganglia pairs
- 3 cervical (superior, middle, inferior)
- thoracic 11-12
- lumbar 3-5
- sacral 3-5
- single coccygeal
61
what is the stellate ganglion
combination of inferior cervical ganglion & T1 ganglion
62
only splanchnic nerves to carry PNS fibers
pelvic splanchnic nerves
63
function of splanchnic nerves
deliver preganglionic SNS fibers to prevertebral delay ganglia and plexuses distribute postganglionic fibers
64
the intermediolateral nucleus lies within which of Rexed's lamina
7
65
white rami are found only at spinal cord levels:
T1-L2/L3
66
which ganglia are sites for sympathetic synaptic relays
sympathetic chain ganglia & prevertebral ganglia
67
what is a ganglion
a peripheral collection of nerve cell bodies (soma)
68
3 thoracic splanchnic nerves
1. greater
2. lesser
3. least
69
which plexus may be blocked for relief of pain due to chronic pancreatitis
celiac plexus
70
how do somatic sympathetic groups generally travel to effectors
via spinal nerves
71
where do preganglionic SNS neurons to adrenal medulla arise in spinal cord
IML T4-T12
72
where do ALL preganglionic sympathetic neurons arise from?
T1-L3
73
what is the largest sympathetic plexus
celiac
74
ganglia that are sites for sympathetic synaptic relays
sympathetic chain ganglia
prevertebral ganglia
75
ganglion of spinal segment T1-2
superior cervical
76
provides SNS innervation to colon, urinary bladder, reproductive organs
lumbar sphanchnic nerves
77
what do postganglinoic axons of lesser splanchnic nerves innervate
GI tract, kidneys, bladder, reproductive organs
78
where do postganglionic fibers from cervical ganglia distribute
structures in head, neck, heart, lungs
79
what forms the greater splanchnic nerve
a group of visceral SNS preganglinoic nerves from T5-T9/10 that traverse the sympathetic trunk ganglia
80
function of greater splanchnic nerve
synaptic relays in the celiac and superior mesenteric ganglia
from there, postganglionic fibers are distributed to upper GI via prevertebral plexuses
81
plexus with distribution to smooth muscle of esophagus
cardiac plexus
82
plexus with distribution of postganglionic sympathetic fibers to sigmoid colon
aortic & hypogastric
83
plexus with distribution of postganglionic sympathetic fibers to liver & gallbladder
celiac plexus
84
plexus with distribution to cardiac tissues
cardiac plexus
85
largest sympathetic plexus
celiac
86
plexus that lies at L1
celiac
87
plexus with distribution of postganglionic sympathetic fibers to reproductive organs
hypogastric plexus
88
another name for stellate ganglion
cervicothoracic ganglion
89
cranial nerves with PNS components
CN 3, 7, 9, 10
90
somatic efferents of oculmotor nerve
motor supply to certain extraocular skeletal muscles (levator palpebrae superioris, superior/medial/inferior rectus, inferior oblique
91
visceral (PNS) efferents of oculomotor nerve
innervate specific intraocular muscles (pupillary sphincter, ciliary muscle)
92
PNS component of facial nerve
Carries PNS efferent innervation to submandibular, sublingual, and lacrimal glands
93
main sensory component of CN 7
facial nerve
carries taste from anterior 2/3 tongue via chorda tympani
94
motor components of CN 9
1) visceral efferents to pharyngeal constrictor skeletal muscles
2) visceral effects – PNS fibers – to parotid glands
95
sensory components of CN 9
1) somatosensory supplies to posterior 1/3 tongue, soft palate, pharyngeal mucosa, tonsils, eustachian tube, tympanic membrane, external ear
2) special visceral afferents from taste buds to posterior 1/3 tongue
3) general visceral efferents from carotid bodies and carotid sinus
96
supplies about 75% of PNS outflow to the body
CN 10
97
motor components of CN 10
1) visceral efferents to pharyngeal skeletal muscles, skeletal muscles of soft palate, and all laryngeal muscles
2) visceral efferents (PNS fibers) to thoracic & abdominal viscera
98
sensory components of CN 9
1) modest somatosensory supply to ear, dura of posterior fossa
2) special visceral afferents from tastebuds on the epiglottis
3) transmitting sensations from pharynx, larynx, barorecepors, chemoreceptors, thoracic & abdominal viscera
99
Origin of vagal efferents
nucleus ambiguous & dorsal motor nucleus
100
PNS outflow arises from spinal cord levels:
S2-S4
101
list the 4 relay ganglia for CN sympathetic pathways
ciliary (CN 3)
pterygopalatine (CN 7)
submandibular (CN 7)
otic (CN 9)
102
postganglinoic PNS fibers of CN 7 & 9 reach targest by hitchhiking on branches of which nerve?
CN 5
103
5 nerve plexuses that distribute PNS fibers to viscera
pharyngeal
cardiac
pulmonary
esophageal
celiac
104
which CN is superior salivatory nucleus assoc with
CN 7
105
CN associated with inferior salivatory nucleus
CN 9
106
2 routes preganglionic fibers originating in superior salivatory nucleus can take
1. to pterygopalatine ganglion - petroal nerve = pterygopalatine relay ganglion
2. leave via facial n. in chorda tympani branch - joins lingual n. - submandibular ganglion
107
how do preganglionic fibers originating in inferior salivatory nucleus leave brainstem
with CN 9
108
most CNS neurons are multipolar are unipolar?
multipolar
109
where do cell bodies of pseudounipolar sensory neurons lie?
DRG
110
where do sympathetic efferent pathways start and end
start: CNS
end: effector (target) organs
111
where do visceral afferent pathways start and end
start: organs
end: CNS
112
what classification of nerve fibers are visceral afferents
A delta and C
113
visceral afferents from the heart travel in the vagus nerve to the:
NTS (nucleus tractus solitarius)
114
cell bodies of sympathetic afferent fibers are in the:
dorsal root ganglia
115
cell bodies of sympathetic afferent fibers are in the:
dorsal root ganglia
116
which CN with PNS components does NOT transmit sensory information
CN 3
117
noxioius visceral sensations generally travel in which division of ANS?
sympathetic
118
receptors that mediate majority of PNS physiologic effects
mAChRs
119
muscarinic receptors in PNS division
M1, M2, M3
120
muscarinic receptor assoc. with cerebral vasoconstriction
M1
121
muscarinic receptor found in heart
M2
122
muscarinic receptor assoc with bronchoconstriction
M3
123
signal transduction of M2 & M4 receptors
Gi, G0
124
effectors of M2 & M4 receptors
inhibit adenylate cyclase
125
signal transduction of M1, M3, and M5
Gq
126
effector of M1, M3, and M5
PLC activation (Gq)
127
location of N-N receptors
autonomic ganglia
adrenal medulla
128
muscarinic receptors that cause cerebral vasodilation
M2, M5
129
muscarinic receptors assoc with increased insulin secretion
M3
130
location of M1 receptors
autonomic ganglia
glands
131
location of N-N receptors
Autonomic ganglia
Adrenal medulla
132
location of M2 receptors
Heart
Smooth muscle
ANS nerve terminals
133
location of M3 receptors
Smooth muscle
Glands
134
muscarinic receptors assoc with increased Na+ permeability
NN
135
what enzyme catalyzes the synthesis of ACh
ChAT - choline acetyltransferase
136
another name for en passant synapses
neuroeffector junctions
137
what is stored in postganglionic terminal varicosities
neurotransmitters
138
signal transduction of alpha 1 receptors
Gq/11
139
alpha 1 receptor effectors
activates PLC
140
signal transduction of alpha 2 receptors
Gi; G0
141
effectors of alpha 2 receptors
inhibit AC
Calcium, K channels
142
signal transduction of beta receptors
Gs
143
effectors of beta receptors
stimulates AC
calcium channels
144
alpha receptor assoc. with vasoconstriction of aorta and coronaries
alpha 1D
145
alpha receptors assoc with cardiac growth & remodeling
alpha 1B
146
alpha receptors in blood vessels, heart, lung, liver, smooth muscles, vas deferens, prostate
alpha 1A
147
molecular/cellular response of alpha 1 receptors
• Coupled to Gq to activate PLC = ↑ IP3/DAG
• Modulate K+ channels
• ↑ Na+/H+ exchanged
148
adrenergic receptor with central components of baroreceptor reflex
alpha 2A
149
molecular response of alpha 2A receptors
Coupled to Gi to inhibit AC = ↓ cAMP, PKA
150
predominant receptor for 2 mediated vasoconstriction
alpha 2B
151
location of alpha 2 C receptors
presynaptic sympathetic nerve terminals
152
adrenergic receptor assoc with decreasd NT release from adrena medulla
alpha 2C
153
adrenergic receptor that activates L type calcium channels
Beta 1
154
adrenergic receptor assoc with lipolysis in adipocytes & thermogenesis
beta 3
155
adrenergic receptor assoc with skeletal muscle glycogenolysis & hypertrophy
beta 2
156
adrenergic receptor responsible for melatonin synthesis
beta
157
SNS neurotransmission with postganglionic cholinergic fibers
exocrine glands
158
ACh released from postganglionic SNS to exocrine glands mainly binds to what receptor
M3
159
how do sweat glands release sweat
exocytosis
160
co-released with NE from postganglionic fibers to decrease amount of NE released
NPY (neuropeptide Y)
161
co-localized with ACh in preganglionic neurons to regulate SNS activity at ganglia
NO
162
co-released with NE for SNS stim of vascular smooth muscle
ATP
163
adrenergic receptor assoc with decreased preganglionic NE release
alpha 2
164
adrenergic receptor assoc with decreased preganglinoic ACh release
alpha 2
165
adrenergic receptor assoc with increased renin release
beta 1
166
intraocular muscle contraction that causes mydriasis
radial muscle
167
intraocular muscle contraction that causes miosis
spincter pupillae (circular) muscle
168
3 typical features of horners syndrome
1. miosis
2. partial ptosis
3. ipsilateral anhidrosis
169
what causes miosis in horners syndrome
paralysis of dilator pupillae muscle
170
what causes ptosis in horners syndrome
- paralysis of superior tarsal muscle of levator palaprae superior
- ascending SNS outflow blockade at stellate ganglion
171
what causes ipsilateral anhidrosis in horners syndrome
absence of sweating d.t absence of innervation to sweat glands
172
innervates orbitalis muscle
superior cervical ganglion (SNS fibers)
173
cardioaccelerator nerves
T1-T4
174
complementary SNS & PNS innervation in salivary glands
- SNS = NE acts on alpha 1 and beta = thick secretions
- PNS = CN 7 & 9 = copious watery secretions via ACh acting on M3
175
PNS only innervation
lacrimal glands, ciliary muscle (near vision accommodation), nasopharyngeal glands
176
SNS only innervation
adrenal medulla, most blood vessels, erector pili, gallbladder, kidney, exocrine sweat glands
177
most important integrator of ANS & endocrine function
hypothalamus
178
most important factors controlled by brainstem
arterial pressure, HR, resp control
179
major lower brainstem command center for visceral control
NTS in brainstem
180
greatest concentration of autonomic centers
hypothalamus
181
mediates interactions between limbic system and brainstem
hypothalamus
182
major lower brainstem control center for visceral control
NTS
183
ANS influences all tissues EXCEPT:
skeletal muscle tissues
183
ANS influences all tissues EXCEPT:
skeletal muscle tissues
184
1st line defense against arterial BP changes
baroreceptor reflex
185
procedures that affect baroreceptor reflex
CEA
mediastinoscopy
186
what indicates that baroreceptor reflex is preserved
heart rate increases with hypotension or decreases with HTN
187
what is the bainbridge reflex
tachycardia r/t increased venous return
188
reflex that prevents damming or sludging of veins, atria, and pulm circulation
bainbridge
189
counterbalance to baroreceptor reflex
bainbridge
190
cardioinhibitory reflex
Bezhold-Jarisch
191
triad of bezhold jarisch reflex
Bradycardia, hypotension, & coronary dilation
192
↓ HR & BP during spinal epidural attributed to what reflex
Bezhold-Jarisch
193
strongest drive at peripheral chemoreceptors
hypoxia
194
what causes vasovagal syncope
- transient decreased perfusion to the brain
- massive PNS stimulation, abolition of SNS tone
195
effector response of oculocardiac reflex
decreased activity of SA and AV nodes
196
Reflex that fatigues with subsequent occurrences
oculocardiac
197
what is the CNS ischemic reflex
blood flow to medullary vasomotor center decreases enough to cause cerebral ischemia
massive SNS activation = vasoconstriction and increased BP
198
one of the most powerful of all activators of SNS vasoconstriction
CNS ischemic reflex
199
when does CNS ischemic reflex response become signifncant
MAP < 50
200
greatest degree of CNS ischemic reflex stimulation
MAP 15-20
201
control center for thermoregulatory reflexes
hypothalamus
202
how is nonshivering thermogenesis in newborns & infants modulated
by NE from adrenergic nerve terminals
203
what is the mass reflex
simultaneous excitation of all segmental spinal reflexes
(autonomic hyperreflexia)
