ANS blood pressure Flashcards
What regulates cardiovascular function?
the autonomic nervous system (ANS) monitors and modulates blood pressure and SA node activity
What is a center/ brain center
a collection of interneurons that receive sensory input about a functions and create motor output to alter that function
cardiovascular centers are located in… and divided into… centers
hind brain and divided into 2 centers
cardiovascular center - cardiac control
- heart rate
-cardioaccelatory neurons (increase heart rate)
sympathetic
visceral motor neurons
Norephinephrine (NE)
increase rate of action potentials of SA node
-cardioinhibitory neurons (decrease heart rate)
parasympathetic
viceral motor neurons
acetylcholine (ACh)
rate of action potentials decrease
cardiovascular center - vasomotor control
-vessels
-vasoconstriction
-vasodilation
variables that affect blood pressure
-cardiac output
-compliance
-volume and viscosity of blood
-blood vessel diameter
Cardiac output
Amount of blood the left ventricle pumps in 1 minute
CO= Stroke volume x Heart rate
higher cardiac output = higher pressure
Compliance
ability of a compartment to expand to accommodate increased content
- low compliance = higher blood pressure
Volume and viscosity of blood
increase blood volume/viscosity = higher blood pressure
Change in vessel diameter
vasoconstriction–> smaller vessel diameter, higher blood pressure (sympathetic)
Vasodilation—–> larger vessels, lower blood pressure (parasympathetic)
How does the body maintain blood pressure at rest?
using a visceral neural circuit
examples where blood pressure is altered at rest?
change in. posture, hydration state, stress, or disease
first step in blood pressure neuronal circuit
starts with sensory input to cardiovascular control center in medulla
what causes baroreceptors to depolarize?
arterial stretch due to increasing pressure
describe baroreceptors
neurons with mechanical-gated sodium channels (open when vessel is stretched)
- found in aorta and carotid sinus