Autonomic Nervous System Flashcards
Sympathetic/parasympathetic nerve roots
S: T1-L3, synapse early. P:3, 7, 9, 10. synapse closer to the site of action.
What type of neurotransmitter in baroreceptor afferents?
glutamate
Which nerve transmits from aortic baroreceptor
vagus
Which nerve transmits from carotid body/sinus
glossopharyngeal
Which neurotransmitter is released by sympathetics stimulating the heart?
norepinephrine
Which neurotransmitter is released by parasympathetics stimulating the heart?
acetylcholine
Where do the baroreceptor afferents synapse? Where do the sympathetic and parasympathetic efferents emerge respectively?
nucleus solitarius in the caudal medulla. Rostral medulla, nucleus ambiguas.
Which type of neurotransmitter is used in the ganglia?
acetylcholine
Adrenonergic
binds catecholamines
NANC
non adernergic non cholinergic. relase purines or peptides.
In which part of the brain stem to the sympathetics originate?
The RVLM rostroventrolateral medulla
In what part of the brain stem do the parasympathetics originate?
the nucleus ambiguous.
What types of receptors are in the autonomic ganglia?
nicotinic receptors
What type of neurotransmitter is release by sympathetics stimulating the renal vasculature and the skin/sweat glands?
dopamine and acetylcholine respectively.
Cholinergic transmitter synthesis and secretion
choline actively pumped into cell, fused with acetyl-coA by transferase and moved into vesicle. Exocytosis induced by calcium. Acetylcholine esterase degrades in the synaptic space.
Noradernergic transmitter synthesis and secretion
tyrosine is actively pumped into the neuron, where it is transformed into DOPA, which is transformed into dopamine, which is transferred into a vesicle and transformed into norepinephrine, which is then exocytosed when calcium influxes. NE is both degraded an pumped back in
alpha 1 receptor locations
vascular smooth muscle, glands.
alpha 1 receptor mechanisms of action
Gq protein causes rise in IP3 and DAG, casing increasing in calcium leading to secretion and muscle contraction. GENERALLY CONSTIRCT
alpha 2 receptor locations
nerve endings, some smooth muscle
alpha 2 mechanisms of action
Gi receptor causes a drop in cAMP, leading to neurotransmitter release block? and smooth muscle contraction
beta 1 receptor locations
cardiac muscle, JGA
beta 1 receptor mechanisms of action
bind to Gs leading to an increase in cAMP which causes an increase in HR and contractility. In the kidney causes renin release.
Beta 2 receptor locations
bronchiolar smooth muscle, liver, heart. GENERALLY DILATE, relax
beta 2 receptor mechanism of action
Gs receptor leads to increase in cAMP which relaxes smooth muscle, increases glycogenolysis, increases hr and contractility
beta 3 receptor locations and actions
Gs receptor in adipocytes causes increase in cAMP leading to lipolysis.
Dopamine receptor locations and actions
dopamine receptors in the kidneys relax SM in renal arterioles by way of Gs increasing cAMP
What is the base molecule for adrenergic molecules
tyrosine.
Aceythcholine structure
(CH3)COOC2(N(CH3)3)
Production of acetylecholine
choline is transported into the cell and fused with acetyl CoA to make acetyle choline. It is then moved into synaptic vesicles and transported to the synaptic cleft where it is extruded. Acetylcholinesterases rapidly breack down acetylcholine in the synaptic cleft, allowing acetate to disassociate and choline to be reuptaken by the cell
M1 receptor
Parasympathethic nerve endings, Gq 2nd messenger, activates myenteric system
M2 receptors
Located in the heart, some nerve endings, Gi coupled (cAMP down, activat K+ channels). Slow the SA node
M3 receptors
Smooth muscle, glands, endothelium. Gq, contract detrusor muscle, increase salivation
Nn receptors
All ANS ganglia, Na-K ion channel, Depolarized postganglionic neurons
Nm receptors
neuro-muscular junction, Na channel, Depolarizes muscle cells, evokes AP and contraction
Excessive cholinergic stimulation causes:
diarrhea, urination, miosis, bronchorrhea, bradycardia, exictation of skeletal muscles(paralysis) +emesis, lacrimation, salivation, sweating
Reduced cholinergic output causes:
blurry vision, dilated pupils, hyperthermia, dry skin, erythema, hallucinations, coma, memory loss, tachycardia. (blind as a bat, mad as a hatter, red as a beet, dry as a bone, hot as a hare).
