15. Circulation and Hemodynamics Flashcards
What is the starling equation?
Jv = Kf [(Pc-Pi) – (πc – πi)]
What does arteriosclerosis do to blood pressures?
Arteriosclerosis will increase systolic blood pressure, pulse pressure, and mean arterial pressure - but will not really increase diastolic pressure
What will aortic stenosis do to blood pressures?
Aortic Stenosis is a narrowing of the aorta, which will decrease systolic pressure, pulse pressure, and mean arterial pressure.
What is the equation for mean arterial pressure?
Mean arterial pressure = ⅔ (diastolic) + ⅓ (systolic)
What is the equation for compliance?
Compliance = Volume / Pressure
What does reynold’s number predict?
Whether or not flow will be “laminar.”
What is reactive hyperemia?
Increase in blood flow in response to a period of ischemia
What is the metabolic hypothesis for local control of blood flow?
States that oxygen delivery is matched to oxygen consumption. Vasodilatory metabolites are increased as a result of increased oxygen consumption.
What is the myogenic hypothesis for local control of blood flow?
“Can explain only autoregulation. States that a stretch in smooth muscle will cause a contraction of the same smooth muscle, so increased blood pressure causes increase in resistance and reduction in blood flow. Also, greater shear stress is synonymous with greater pressure, so smooth muscle constricts in response.”
What is the main role of histamine in the vessels?
Dilates arterioles and constricts venules to increase filtration
What is the main role of serotonin in the blood vessels?
Local vasoconstrictor
What is the primary role of the prostaglandins in blood vessels?
- Prostaglandin E-Series and Prostacyclin
- Dilation
- Thromboxane A2 and Prostaglandin F-Series
- Constriction
What is the role of vasopressin in blood vessels?
Vasoconstriction
What special circulation does not use much local metabolic control?
The skin
How does thyroid hormone increase temperature?
Stimulates sodium potassium pump increasing O2 consumption and metabolic rate
