Basic Concepts 2 b Flashcards
classical view of the ANS: characteristics of symp vs. para
large diffuse adrenergic sympathetic system, balanced by smaller and more specifically directed cholinergic parasymp. system
ganglionic vs. post ganglionic transmission via what NTs and recetpors
ganglionic transmission: ACh on nAChR. post ganglionic parasympathetic effects via mAChR. post ganglionic sympathetic via a and b adrenoreceptors
atropine
blocks mAChR so blocks post ganglionic parasympathetic effects
two types of alpha receptors and where they are found
a1 on vascular smooth muscle, usually post synpatic. a2 on presynaptic nerve terminals
two types of b-adrenoreceptors
B1: heart, more sensitive to NA. V2 in other tissues. B3 has been defined. also have excitatory B autoreceptors on sympathetic nerve terminals
adrenoreceptor pharmacology: alpha 1 and 2 what is the order of efficacy for adrenergic ligands?
a1: N>A>I (post synpatic)
a2: A>=N»I (presynpatic)
adrenoreceptor pharmacology: beta 1 and 2 what is the order of efficacy for adrenergic ligands?
b1: N>I>A (cardiac)
B2: I>A>N (blood vessels, lungs, etc.)
sympathetic NS: size and specificity? innervates?
large and diffuse. innervates every organ in the body apart from skeletal muscle
most important aspect of sympathetic nerve activity?
ongoing activity responsible for maintaining autonomic tone in various targets
primary role of symp. system
series of precise and differentiated reflex arcs
sympathetic system not essential for life when? but insufficiency?
when in a controlled and comfortable enviornment. insufficiency readily apparent under stress: no activation of compensatory responses to cold, hemorrhage, oxygen deprivation, emotional excitement, fatigue, exercise, fright, danger, etc.
sympathetic NS just fight or flight?
NO, misconception. SNS is continuously active, diffuse by HIGHLY regulated
symp. NS and adrenal system only discharges as a ___ during?
as a unit, during rage and fright such that sympathetically innervated structures are affected simultaneously
sympathetic syndrome/flight or fight: what happens
increased HR and BP. blood flow shifted away from skin/planchnic regions towards skeletal muscle. blood glucose rises. pupils and bronchioles dilate.
ANS controls ___ (3) as well as specific targets like ___ (3)
exercise, thermoregulation, immune response. specific targets like heart, guts, lungs
sympathetic NS is ____ (3 characteristics)
diffuse, constantly activated, highly regulated
adrenergic agonists act on what receptors? ACh?
alpha and beta receptors. muscarinic and nicotinic receptors.
parasympathetic system organized mainly for _____? contrasts with sympath. system which is?
mainly for localized discharge within a limited number of target tissues aka it is anatomically directed vs. the diffuse and regulated symp. system.
parasympsthetic system concerned mostly with what 2 things
conservation of energy. maintenance of organ function during periods of minimal activity
activation of parasympathetic nerves: 5 effects
decrease HR. lower BP. stimulates GI movements and secretions. facilitates nutrient absorption. empties bladder/rectum
parasympsthetic outflow is directed: because of what (2)
no such thing as parasympathetic syndrome. rapid parasymp. reflex to constrict pupils to protect retina from bright light (and see no other parasymp effects, just one directed localized effect)
generally: parasymp = what with muscles? symp = ?
parasymp = relaxation of smooth muscle, secretion. symp = smooth muscle contraction
autonomic tone: many visceral organs receive? exceptions?
both parasymp and symp innervation. exceptions: spleen, kidney, blood vessels = only sympathetic
liver and fat cells have what innervation
adrenergic sympathetic innervation, perhaps also non cholinergic parasymp innervation
