Flashcards in ANS I Deck (31)
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1
What is an agonist? what is an antagonist?
1. agonist = activator
2. antagonist = inactivator
2
What do the following terms mean:
1. ionotropic
2. chronotropic
3. dromotropic
1. ligand gated
2. affecting heart rate
3. affects AV node- conduction of speed
3
What are the sympathetic effects on the heart?
1. stimulation of heart rate at SA node
2. stimulation of AV nodal conduction
3. stimulation of myocardial contractility
4
What are the PNS effects on the heart?
1. Inhibition of HR at SA node
2. inhibition of AV nodal conduction
3. inhibition of atrial contractility
5
Which neurons are myelinated, preganglionic or postganglionic ?
preganglionic
6
What transmitter do somatic neurons release? and what receptor does it bind to?
-ACh
-binds to N1 nicotinic cholinergic receptors
7
What transmitter do preganglionic ANS neurons release and what receptors does it bind to?
-ACh
-binds to N2 nicotinic cholinergic receptors
8
What transmitter does a postganglionic parasympathetic neuron release and what receptor does it bind to?
-ACh
-muscarinic cholinergic
9
What transmitter do postganglionic sympathetic neurons release and what receptors does it bind to?
-Norepinephrine
-alpha or beta adrenergic
10
What neuron activates the adrenal medulla, and how is this accomplished?
-Sympathetic preganglionic neurons release Ach to chromaffin cells
- these cells release epinephrine (80%)
11
Why is sympathetic stimulation of the adrenal medulla long lasting?
The hormones released are inactivated slower
12
When is there an exception to the receptors the sympathetic neurons usually stimulate?
Eccrine glands - muscarinic cholinergic receptors
13
Which type of receptors are ionotropic?
Nicotinic cholinergic - N1, N2
Na+/K+ ligand gated channel
14
What is the antagonist of N1 receptors?
D-tubocurarine
15
What is the antagonist of N2 receptors ?
Hexamethonium
16
What is the antagonist of the M1,M3, M5 muscarinic receptors?
atropine
17
Name the following for M1, 3 ,5 receptors:
1. G protein
2. Linked Enzyme
3. Secondary messengers
1. G alpha q
2. PLC
3. IP3 and DAG
18
Name the following for M2,4 receptors:
1. G protein
2. Linked Enzyme
3. Secondary messengers
1. G alpha 1 and G alpha 0
2. adenylyl cyclase
3. Decreased cAMP
19
Name the following for alpha1 adrenergic receptors:
1. G protein
2. Linked Enzyme
3. Secondary messengers
1. G alpha q
2. PLC
3. IP3 and DAG
20
Name the following for beta adrenergic receptors:
1. G protein
2. Linked Enzyme
3. Secondary messengers
1. G alpha S
2. adenylyl cylcase
3. increased cAMP
21
What is the antagonist of M2 , 4 receptors?
Atropine
22
What is the antagonist of B1 adrenergic receptors?
Propanolol
23
What are some of the effects of the sympathetic nervous system? (8)
1. Inc mydriasis and eyelid retraction
2. Inc HR and force of contraction
3. Inc bronchial dilation
4. Inc vasoconstriction (vasodilation to active muscles)
5. Inc sweating
6. Inc cell. Metabolism
7. Dec GI motility – smooth muscle walls
8. Inc contraction of sphincters
24
Which sympathetic effects result from stimulation of alpha 1 receptors? (3)
1. Mydriasis and eyelid retraction
2. vasoconstriction
3. contraction of sphincters
ex. receptor in the internal sphincter found in the bladder
25
Which sympathetic effects result from stimulation of beta 1 receptors? (1)
- Increased heart rate and force of contraction
26
Which sympathetic effects result from stimulation of beta 2 receptors? (2)
-bronchial dilation
-also on the detrusor muscle in the bladder for relaxation
27
Which sympathetic effects result from stimulation of both alpha and beta receptors? (2)
1. decreased GI motility - smooth muscle walls
2. increased cellular metabolism - epi from medulla
28
What receptors does epinephrine have a greater affinity for? Where do these primarily exist?
Beta adrenergic -- heart, liver, lungs
29
What does norepinephrine have a greater affinity for? Where are these primarily expressed?
Alpha adrenergic receptors - vasculature
30
What hormone does the adrenal medulla secrete more of?
80 % epinephrine
20% norepinephrine
31
