Homeostasis 3 Flashcards
____ system critical in metabolic regulation? what other system plays a role?
endocrine system critical. nervous system also plays a role (food intake)
hourly regulation of metabolism depends on?
push pull mechanism between insulin and glucagon
insulin and glucagon half lives? so require?
short half lives = continuous secretion
in the fed state: which hormone dominates? net metabolic effect?
insulin dominates = net anabolism. glucose used up for energy production, excess glucose stored as glycogen or fat
fasted state: which hormone dominates? main effects?
glucagon dominance: liver uses glycogen and other intermediates to synthesize glucose.
4 determinants of mean arterial pressure
heart rate. stroke volume. cardiac output. total peripheral resistance
short term regulation of mean arterial pressure: time line? regulate what? involve what body parts? what control?
seconds to minutes: regulate cardiac output, total peripheral resistance. involves heart + blood vessels. neural control
long term regulation of mean arterial pressure: time line? regulate what? involve what body parts? what control?
minutes to days. regulate blood volume. involve kidneys. hormonal control.
negative feedback loop for MAP: detector? integrator? controller? effector?
detector = baroreceptors. integration centers = cardiovascular centers in brain stem. controllers = ANS. effectors = heart and blood vessels.
arterial baroreceptors: detect what? location?
stretch receptors. in carotid sinus and aortic arch
atrial volume, aka ___ receptors, maintain?
cardiopulmonary - maintain tonic depression of sympathetic outflow
baroreceptor response to increased or decreased arterial pressure.
high BP: increased AP frequency. decreased pressure = less stretch = decreased AP frequency
effect of barorecptor and CP receptor denervation?
baroreceptor denervation = MAP unaltered but way broader curve, large range in pressures. also cut CP receptors: same thing but MAP also increased.
cardiovascular control centre: where? what?
medulla oblongata. integration center for blood pressure regulation.
cardiovascular control center: 5 inputs?
arterial baroreceptors. low pressure baroreceptors. chemoreceptors. proprioceptors. higher brain centers.
cardivascular control center: 2 out puts?
sympathetic and parasympathetic nervous system
following hemorrhage: what happens? reflex compensation?
baroreceptor reflex = increase in sympathetic activity + decrease in parasympathetic = reflex compensation toward normal
following hemorrhage: limits of baroreceptor reflex? so you need?
short term control of blood pressure, only toward normal. ultimately you’d need to shift blood volume control.
long term regulation of blood volume: receptors? to what center? effects?
cardiopulmonary receptors. ANS. renal arteriolar vasoconstriction, renin-angiotensin aldosterone system activation, more ADH and less ANP = more water and salt reabsoprtion
neural modulation in exercise: large increase in ___activity? anticipation originates in?
sympathetic activity. stress or anticipation of exercise originates in cerebral cortex
