23: peripheral circulation and regulation of flow Flashcards
Characteristics of alpha receptors
Located on vasculature
mediate vasoconstriction
Purpose of B-2
mediates vasodilation
What determines sensitivity to input
Receptor density
What is the final central pathway for modulation of sympathetic and parasympathetic drive
Medula
Baroreceptors
Stretch receptors on the aortic arch and carotid
Purpose of baroreceptors
detect arterial pressure changes through changes in the stretch on vessel walls
Important short term regulation of pressure
What does increased baroreceptor input excite
parasympathetic preganglionics
What are arterial chemoreceptors sensitive to
Blood O2 levels
Main purpose of cardio system
maintain oxygen levels to vital organs through vasoconstriction of all other vascular beds
What is the primary compensatory mechanism to increase blood oxygenation
Respiratory system
Cardio response to sever hypoxia
Tachy or bradycardia
Main reflex action of atrial stretch receptors
increase heart rate
Bainbridge reflex
increase HR
Increase diuresis
How is brainbridge reflex modulated
Selective changes in renal flow
Changes in renal capacity for water reabsorption
Extrinsic reflexes
Pain
Cold
