Autonomic Nervous System Flashcards
The sympathetic pathway for the NOREPINEPHRINE is:
1- Thoracolumbar origin (T1-T2)
2-Preganglia near spinal cor
3-Postganglia secrete norepinephrine (NE)
4-Adrenergic Fibers
Dopamine Beta Hyroxylase converts dopamine into:
Norepinephrine
What is the process for NOREPINEPHRINE signal termination?
1-Reuptake
2-Dilution by Diffusion
3-Metabolism
What enzymes will metabolize Norephinephrine?
Monamine oxidase (MOA) and Catechol-o-methyltranserase (COMT)
(SYMPATHETIC) Alpha-1 (adrenergic receptor) is __________ and controls mainly the ________.
Postsynaptic, peripheral vascular
(SYMPATHETIC) Beta-1 (adrenergic receptor) and controls the _____.
Heart
(SYMPATHETIC) Beta 2 (adrenergic receptor) controls other ______ ______ such as the _____:
Smooth muscles, Lung
(SYMPATHETIC) Alpha -1 Postsynaptic Receptors control functions such as:
- Activation increases intracellular calcium
- Smooth muscle contraction
- Peripheral vasoconstriction
- BRONCHOCONSTRICTION
- Inhibits Insulin secretion
- Stimulates glycogenolysis and gluconeogenesis
- Mydriasis
- GI relaxation
(SYMPATHETIC) Alpha-2 PRESYNAPTIC (peripheral nervous system) receptors control functions such as:
- Decreases entry of calcium into the cell
- Limits the release of norepinephrine
(SYMPATHETIC) Alpha-2 POSTSYNAPTIC (central nervous system) receptors control functions such as:
Sedation
Decreased sympathetic outflow
Decreased BP
Platelet aggregation
(SYMPATHETIC) Beta-1 Postsynaptic receptors control functions such as:
- Increases HR
- Increases conduction velocity
- Increases myocardial contractility
(SYMPATHETIC) Beta-2 Postsynatic receptors control functions such as:
- Stimulation leads to smooth muscle relaxation
- Peripheral vasodilitation
- Decreases BP
- BRONCHODILITATION
- Increases insulin secretion
- Increases glycogenolysis and gluconeogenesis
- Decreases GI mobility
The parasympathetic nervous system (PNS) originates from:
- Craniosacral origin (III, V, VII, X)
- Preganglia near organs of innervation
- Postganglia secrete acetylcholine (ACh) cholinergic fibers
T/F: acetylcholine activates both arms of the SNS.
TRUE
What creates Acetylcholine?
Choline and Acetyl CoA (Choline acetyltransferase)
What deactivates acetylcholine?
Acetylcholinesterase
What are the receptors for the parasympathetic nervous system:
Cholinergic
- Nicotinic
- Muscarinic
____ _____: extended exposure to agonists reduces the number, but not their response. Results in tachyphylaxis.
Down Regulation
_____ ______: chronic depletion of catecholamines or use of antagonists increases the number of receptors, but not their sensitivity. May account for withdrawal syndrome with beta blockers.
Up Regulation
Explain what receptor uncoupling means:
RECEPTOR DESENSITIZATION/ DOWN REGULATION
- Occurs rapidly
- Inability of the receptor to bind G protein (alter the function of the receptor)
Explain what sequestration means:
RECEPTOR DESENSITIZATION/ DOWN REGULATION:
- Occurs more slowly
- Movement of receptors from the cell surface to intracellular compartments
Explain what Down regulation means:
RECEPTORDESENSITZATION/ DOWN REGULATION
- Prolonged process
- Movement of receptors from the cell surface to intracellular compartments, but then destroyed.
What is it called when there is uncontrolled release of catecholamines due to an adrenal gland tumor?
Pheochromocytoma
T/F: Both neurotransmitters and hormones are catecholamines.
True
What is the site of action for catecholamines:
Adrenergic Receptors
What are the catecholamine neurotransmitters and hormones:
- Dopamine
- Norepinephrine
- Epinephrine
- Isoproterenol
- Dobutamine
What are sympathomimetics:
- Resemble catecholamines except the hydroxyl groups are not present in both the 3 and 4 position of the benzene ring
- Classified to their selectivity for stimulating alpha and /or beta receptors
Points on sympathomimetics INDIRECT-acting:
- Synthetic non-catecholamines
- Release endogenous neurotransmitter NE from postganglionic sympathetic nerve endings
Points on sympathomimetic DIRECT-acting:
-Catecholamines and synthetic non-catecholamines
Name some sympathomimetics:
Ephedrine
Phenylephrine
What effect does aging have on autonomic dysfunction:
- Orthostasis
- Temperature instability
- Decreased stress response
- Decrease pre-junctional terminals
What will diabetes have on autonomic dysfunction:
- Diarrhea
- Impotence
- Hemodynamic instability hypotenstion
- Gastroparesis
The adrenal medulla release __% epi and __% Norpinephrine.
80, 20
T/F: The adrenal medulla hormone release is triggered by Ach at cholinergic fibers due to SODIUM ion influx.
FALSE (CALCIUM ion influx)
(SYMPATHETIC) Alpha 2 (adrenergic receptor) is _________ and controls _______.
Presynaptic, sedation
