ANS Anatomy and Physiology Flashcards
(107 cards)
1
Q
2 divisions of the Peripheral NS
A
Somatic and Autonomic (visceral)
2
Q
Somatic nerves innervate?
A
Skeletal muscle and sensory skin
3
Q
Autonomic Nerves Innervate?
A
Smooth muscle, cardiac muscle, glands
4
Q
Afferent nerves transmit?
A
Sensory incoming
5
Q
Efferent nerves transmit?
A
Motor outgoing
6
Q
3 Divisions of the ANS
A
Sympathetic
Parasympathetic
Enteric
7
Q
What is the big-picture function of the ANS?
A
Maintaining physiologic homeostasis
8
Q
3 forms of extracellular signals and an example of each
A
- Chemical - hormones, neurotransmitters, drugs
- Electrical - membrane voltage
- Mechanical - pressure
9
Q
3 Major categories of membrane-bound receptors
A
- ion channel
- G- protein-coupled
- Enzyme-linked
10
Q
2 ways a G-protein coupled receptor works
A
- opens or closes ion-channel
- Activates or inhibits an enzyme inside the cell
11
Q
What 2 compartments are intracellular receptors located?
A
- cytoplasm
- nucleoplasm
12
Q
List the sequence of events of signaling through g-protein-coupled receptors
A
First messenger (Ligand)
GPCR
Effector
Second Messenger
Cellular Response
13
Q
Name the three subunits of a GPCR
A
alpha beta gamma
14
Q
What are the 5-second messengers we need to know
A
- cAMP
- cGMP
- DAG (diacylglycerolcerol)
- Inositol triphosphate (IP3)
- Calcium Ion
15
Q
Which 2 G proteins turn on an effector?
A
Gs
Gq
16
Q
Stimulation of which receptors increases phospholipase C activity?
A
Alpha-1
Vasopressin -1
17
Q
How does the Gq-coupled protein affect its effector and second messenger?
A
Activates phospholipase C and activates IP3, DAG, Calcium
18
Q
What is the effector for Gq-coupled proteins?
A
Phospholipase C
19
Q
What is the effector for Gs and Gi-coupled proteins?
A
Adenylate Cyclase
20
Q
How does the Gs-coupled protein affect its effector and second messenger?
A
Activates adenylate cyclase
Activates cAMP
21
Q
How does the Gi-coupled protein affect its effector and second messenger?
A
Inhibits Adenylate Cyclase
Inhibits cAMP
22
Q
What are the 6 Gq protein-coupled receptors
A
Alpha 1
Muscarinic 1
Muscarinic 3
Muscarinic 5
Vasopressin 1 (vasculature)
Histamine 1
23
Q
What are the 4 Gi protein-coupled receptors?
A
Alpha 2
Muscarinic 2
Muscarinic 4
Dopamine 2 (presynaptic)
24
Q
What are the 6 Gs protein-coupled receptors?
A
Beta 1
Beta 2
Beta 3
Dopamine 1 (post-synaptic)
Vasopressin 2 (renal-tubules)
Histamine 2
25
Nicotinic Receptors (ANS ganglia, NMJ & CBS) have what signal transduction?
Ion Channels
26
Sympathetic activation of the heart is caused by what receptor? What are the effects when that receptor is activated?
Beta 1
Positive Inotropic, Chronotropic, Dromotropic
27
What receptor causes the parasympathetic activation of the heart? What are the effects when that receptor is activated?
Muscarinic 2
Negative Inotropic, Chronotropic, Dromotropic
28
What receptor causes the sympathetic activation of the lungs? What are the effects when that receptor is activated?
Beta 2
Bronchodilation
29
What receptor causes the parasympathetic activation of the lungs? What are the effects when that receptor is activated?
Muscarinic 3
Bronchoconstriction
Increase in gland secretions
30
What receptor causes the sympathetic activation of the GI tract? What are the effects when that receptor is activated?
Alpha 1
Vasoconstriction
Sphincter Contraction
31
What receptor causes the parasympathetic activation of the GI tract? What are the effects when that receptor is activated?
Muscarinic 3
Increased Motility
Sphincter Relaxation
Increase Gland Secretion
32
What receptor causes the sympathetic activation of the Glands? What are the effects when that receptor is activated?
Alpha 1
Increased Sweating
Decreased Pancreatic Activity
33
What receptor causes the parasympathetic activation of the Glands? What are the effects when that receptor is activated?
M1, M3
Increased Salvation
Increased Lacrimation
Increase Pancreatic Activity
34
What receptor causes the sympathetic activation of the urinary tract? What are the effects when that receptor is activated?
Alpha 1, Beta 2
Bladder sphincter contraction
Increased Renin Secretion
35
What receptor causes the parasympathetic activation of the urinary tract? What are the effects when that receptor is activated?
M3
Bladder sphincter relaxation
36
What receptor causes the sympathetic activation of the skin? What are the effects when that receptor is activated?
Alpha 1
vasoconstriction
37
What receptor causes the sympathetic activation of the skeletal muscle? What are the effects when that receptor is activated?
Beta 2
Vasodilation
38
What receptor causes the sympathetic activation of the pupils? What are the effects when that receptor is activated?
Alpha 1
Dilation
39
What receptor causes the parasympathetic activation of the pupils? What are the effects when that receptor is activated?
M3
Constriction
40
What are 7 locations of alpha 1 receptors?
Nervous System
Vasculature
Renal Tubules
Pancreas
Platelets
Salivary Gland
GI Tract
41
Effects of alpha 2 stimulation on nervous System
decreased SNS tone
incresed PNS tone
- sedation, hypnosis, analgesia, antishivering
42
Effects of alpha 2 stimulation on vasculature
vasoconstriction
43
Effects of alpha 2 stimulation on renal tubules
inhibit ADH (diuresis)
44
Effects of alpha 2 stimulation on pancreas
decreased insulin release
45
Effects of alpha 2 stimulation on platelets
increased platelet aggregation
46
Effects of alpha 2 stimulation on salivary glands
dry mouth
47
Effects of alpha 2 stimulation on GI tract
decreased gut motility
48
where in the CNS can you find alpha 2 receptors
medulla, locus coeruleus, spinal cord (dorsal horn)
49
What G protein is coupled to presynaptic alpha 2 receptors
Gi
which means inhibition of adenylate cyclase which inhibits cAMP
50
What three areas of a nerve are alpha 2 receptors found
presynaptic, post synaptic, and nonsynaptic (platelets)
51
What occurs when alpha 2 on presynaptic nerves are stimulated (not rapid admin)
NE-releasing neurons in the CNS and PNS are inhibited by the Gi-coupled alpha 2 receptor
52
What metabolizes cAMP to AMP
Phosphodiesterase 3 (PDE 3)
53
cAMP is responsible for "turning on" a variety of?
protein kinases, that instruct cells to perform specific functions
54
What is luistropy?
Rate of cardiac muscle relaxation
55
How does cAMP augment myocardial performance?
1. increases intracellular calcium and force of contraction
2. Increased rate of relaxation. aka increased luistropy
56
In vascular smooth muscle, cAMP produces?
Vasodilation and Decreased SVR
57
What is a PDE3 Inhibitor we use?
Milrinone
58
List 4 situations in which PDE 3 are useful:
1. Beta blocker-induced myocardial depression
2. Acute heart failure
3. Unresponsiveness to IV catecholamines
4. Anytime the combination of increased inotropy and reduced afterload is desired
59
Which PDE is cAMP selective?
PDE 4
60
Which PDE is cGMP selective
PDE 5
61
Which PDE degrades both cAMP and cGMP
PDE 3
62
3 endogenous catecholamines
norepi
epi
dopamine
63
What amino acid is the main precursor for catecholamine synthesis
tyrosine
64
NE inhibits its release by ?
stimulating the presynaptic alpha 2 receptor
65
NE can augment its release by?
Stimulating the presynaptic beta 2 receptor
66
How is 80% of NorEpi removed from the synaptic cleft?
Reuptake - which is an active processes requiring energy
67
What is the primary neurotransmitter in the Parasympathetic NS
ACh
68
Ach stimulates what receptors
cholinergic
69
2 families of cholinergic receptors
nicotinic and muscarinic
70
3 types of nicotinic receptors
Ganglionic (Nn)
Neuronal CNS (Nn)
Skeletal Muscle (Nm)
71
Where are Nn types of ACh receptors found
PNS ganglia
SNS ganglia
CNS
72
Where are Nm type Ach receptors found
Neuromuscular Junction
73
What ion is an antagonist of Ach at the presynaptic nerve terminal?
Magnesium. explains why magnesium can cause muscle weakness and acts synergistically with neuromuscular. blockers
74
How many paired sympathetic ganglia are there?
22
75
Which rami are found at all levels of the spinal cord?
grey rami
76
List the 4 abdominal prevertebral (peripheral) plexuses?
Celiac, Aortic, Superior hypogastric, inferior hypogastric
77
What is horner syndrome
characterized by ipsilateral ptosis, miosis, anhydrosis, flushing of skin, nasal congestion, and enophthalmos
78
What is the stellate ganglion (cervicothoracic)
confluence of the inferior cervical ganglion and T1 ganglion
79
All preganglionic sympathetic neurons (B fibers) arise from?
T1-L2
80
Stellate ganglion provides SNS innervation to?
the ipsilateral head, neck, and upper extremity
81
The stellate ganglion is often blocked for treatment of?
upper extremity dystrophy, complex regional pain syndrome, to increase blood flow to the upper extremity, or to provide relief from intractable post-MI pain
82
Stellate ganglion blockade is often an unintended consequence of?
brachial plexus block
83
Autonomic innervation of the adrenal cortex
Preganglionic sympathetic nerves (T5-T9)
NO post ganglionic nerves
84
How much epi is secreted by the adrenal medulla. what is the percent of total catecholamine output?
0.2 mcg/kg/min 80%
85
Classic triad of symptoms for Pheochromocytoma
headache, tachycardia, diaphoresis
85
How much norepi is secreted by the adrenal medulla. what is the percent of total catecholamine output?
0.05 mcg/kg/min 20%
85
In the hemodynamic management for a patient with Pheochromocytoma, you must?
You must alpha block before you beta block or risk causing heart failure
86
What medications should be avoided if there are suitable alternatives when caring for a Pheochromocytoma pt
Histamine - releasing agents: Succinylcholine, atracurium, mivacurium, morphine
Indirect-Acting Sympathomimetic Agents: Ephedrine
SNS activators: Desflurane, Ketamine, Pancuronium, Naloxone
87
SNS activation stimulates hepatocytes to release?
Glucose and potassium into systemic circulation. it also increases insulin output from pancreatic beta cells (so we can use that glucose)
88
2 phases of potassium response to following SNA stimulation of hepatocytes
1. K released from liver. short term effect.
2. SNS activation causes adrenal medulla to release catecholamines. Epi binds to Beta 2 receptors on skeletal muscle and erythrocytes, which activates the Na/K pump and shifts K into cells.
89
4 factors that shift potassium into cells?
1. Alkalosis
2. Beta 2 Agonists (Epi, Albuterol)
3. Theophyulline
4. Insulin
(temp???)
90
4 factors that shift potassium out of cells?
Acidosis (H+/K+ exchanger)
Cell lysis
Hyperosmolarity
Succinylcholine
91
Preganglionic nerves in the sympathetic NS are?
myelinated B fibers
92
The efferent limb of the ANS pathway consists of 2 nerve fibers:
preganglionic fiber = myelinated B fiber
postganglionic fiber = nonmyelinated C fiber
93
key points of integration between ANS and endocrine system
RAAS
Vasopressin (antidiuretic hormone)
Glucocorticoids
Insulin
94
the ANS influences all tissues except?
skeletal muscle fibers
95
central blood volume and arterial blood pressure are normally maintained within narrow limits by?
neural and hormonal mechanisms
96
What are the 6 cardiac reflexes
Mnemonic "Three Bees in the CV ... Ouch"
Baroreceptor
Bainbridge
Bezold-Jarisch
Chemoreceptor
Vasovagal
Oculocardiac
97
Baroreceptor response to increased BP
Decreased HR, contractility, SVR
98
Baroreceptor response to decreased BP
Increased HR, contractility, SVR
99
What two locations are baroreceptors located in? What nerves correspond and transmit their action potentials?
1. Tranverse Aortic Arch - Vagus N. (CN 10)
2. Carotid Bifurcation - Carotid Sinus - Glossopharyngeal N. (CN 9)
100
Name 2 procedures that may produce bradycardia by the baroreceptor reflex
1. Carotid Endarterectomy
2. Mediastinoscopy
101
Activation of the Bezold-Jarisch reflex manifests as:
Bradycardia, hypotension, coronary artery vasodilation,
Slows the heart in the setting of profound hypovolemia. Idea is to slow to optimize filling
102
What is the sensor for the Bezold-Jarisch reflex
Ventricle chemo and mechanoreceptors. Low preload. Slows the heart in the setting of profound hypovolemia.
Idea is to slow to optimize filling
103
What is the sensor for the Bainbridge reflex?
preload too high. atrial mechanoreceptors.
Increase HR to not allow blood to pool
104
What is the primary area for relay of afferent chemoreceptor and baroreceptor information from the vagus and glossopharyngeal nerves?
Nucleus Tractus Solitarius (in medulla)
105
What is the primary neurotransmitter of the parasympathetic nervous system?
Ach
