Flashcards in ANS Deck (20)
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1
Homeostasis:
Maintaining a stable internal environment within a narrow physiological range amid changing external conditions
2
Inputs to preganglionic neurons:
1. Nucleus of the solitary tract (in medulla): conveys visceral sensory input
2. Other brainstem nuclei: convey environmental stimuli
3. Hypothalamus (in forebrain): conveys internal goals/states
3
The ANS consists of 3 subdivisions
1. sympathetic (flight or fight)
2. parasymp (rest/digest)
3. enteric (semi autonomous control of digestion)
4
Preganglionic: neurotransmitter:
Acetylcholine (ACh)
5
Postganglionic:
Sympathetic: neurotransmitter
Norepinephrine (NE) and epinephrine
6
Postganglionic Parasympathetic: neurotransmitter
ACh
7
Neurotransmitter Receptors:
ACh:
nicotinic vs. muscarinic
8
Neurotransmitter Receptors:
NE:
α- and β-adrenergic
9
Adrenal medulla – functionally, a sympathetic ganglion
1. Innervated by preganglionic sympathetic neurons
2. Releases norepinephrine and epinephrine into bloodstream
3. Widespread sympathomimetic effects (e.g., increased heart rate)
10
Cardiovascular regulation by the nervous system
1. Sympathetic and parasympathetic control of heart rate and force of contraction
2. Baroreceptor reflex
3. Humoral response to low blood pressure
11
ANS regulation of heart rate and force of contraction
1. sympathetic stimulation
2. parasympathetic stimulation
12
ANS sympathetic stim
(via increased NE) –
1. increases blood pressure
2. Increase in heart rate and contractile force
3. Constriction of blood vessels
13
ANS parasympathetic stimulation
(via increased ACh) –
1. decreases blood pressure
2. Decrease in heart rate and
3. decreases contractile force
14
Physiological significance of receptor subtypes
1. Sympathomimetic drugs
2. Parasympathomimetic drugs
15
Sympathomimetic drugs function to
mimic sympathetic activation
16
Sympathomimetic drugs examples
Atropine
17
Atropine is a _____
muscarinic (M2) antagonist in heart
18
atropine does what?
increase HR
19
Parasympathomimetic drugs function to:
mimic parasympathetic activation
20
