Special Circulation Flashcards
What vasoactive metabolites affect coronary circulation?
Hypoxia, adenosine, NO
What is very important for increasing coronary circulation blood flow?
Metabolic hyperemia, which also inhibits vasoconstriction that happens in exercise
How does the heart get oxygen?
It is supplied by the coronary arteries, which are on the epicardium.
When is coronary blood flow the greatest?
During diastole
Coronary flow reserve
difference between maximum flow due to vasodilation and flow at rest
How does coronary circulation respond to increased HR?
Vasodilation (metabolic hyperemia)
Ischemia Heart Disease
Decreased blood flow, caused by atheromatous plaques in coronary vessels in sub endothelial layer caused by poor diet or genetics.
Angina Pectoris
Oxygen demand is greater than oxygen supply due to narrowed coronary arteries. This leads to pain.
What is the goal of angina treatment?
To decrease oxygen consumption by decreasing work load
What is the main control of skeletal muscle at rest?
sympathetic control (NE leads to vasoconstriction)
What kind of hyperemia is prevalent in phasic/dynamic exercise?
Active hyperemia. Blood flow is not interrupted, reduced TPR
What kind of hyperemia is prevalent in static exercise?
Reactive/ischemic hyperemia. Sustained tetanic contractions interrupt blood flow and TRP is increased.
What is the main energy source for the brain?
Blood glucose
What is the most important vasoactive metabolite for the brain?
Carbon dioxide
What is the result of hypoxia in the lungs?
Local vasoconstriction
