L9: Blood pressure Flashcards
What are the consequences of hypertension?
Diagram
What is capacitance?
The change in volume/change in pressure
- Reflects the storage capacity of vessels
What is compliance?
The local change in volume for a given pressure change on a P/V curve.
- Reflects the elasticity of the vessel
Equation for MAP
MAP = Pd + 1/3(Ps-Pd)
Describe the pressure-activity relationship of the arterial baroreceptors with pulsatile and non pulsatile flow
Pulsatile = linear relationship Nonpulsatile = sigmoidal relationship
Where do afferent baroreceeptor endings (glossopharyngeal) first synapse?
NTS of medulla
What is vagal activity activated via?
The NA and dorsal motor nucleus
What is sympathetic activity activated via?
CVLM - inhibits RVLM
What is the parasympathetic output in response to increased blood pressure?
Increased ACh on muscarinic receptors of SA node -> Decreased heart rate
What is the sympathetic output in response to increased blood pressure?
Less NE released -> Vasodilation (less NE binding to alpha receptors on arteriolar smooth muscle) , Decreased force of contraction (Beta-1 receptor) , decreased heart rate (beta1)
How does increased MAP affect stroke volume?
Decreases stroke volume due to peripheral vasodilation
What does the chemoreceptor reflex respond to?
Decreased arterial oxygen, increased carbon dioxide partial pressure, decreased pH
What is the primary cardiovascular response to a reduction in oxygen?
Bradycardia (decrease oxygen consumption by myocardial muscles)
Vasoconstriction -> More oxygen redistributed to brain
