Coronary and Pulm Circulation Flashcards
During what phase of the cardiac cycle is the Heart most perfused?
Ventricular Diastole (rapid filling)
Why is there less pressure in the phasic blood flow on the right side of the heart?
It requires less pressure to open the Pulmonic valve. Lower resistance in the lungs
What is autoregulation?
Being able to maintain a constant bloodflow over a wide range of pressures
How is flow kept constant as pressure changes?
Radius has to increase and decrease in response to pressure. Pressure goes up? Radius increases. converse is also true!
What is the coronary reserve?
The ability of the heart to vasodilate as needed
How does coronary reserve change during disease?
It decreases.
How is metabolism of the heart regulated in response to demand?
Vasodilation occurrs to supply more blood
What is the sympathetic regulation of the heart?
1st NE causes vasoconstriction
2nd Increased Force of contraction and HR
What equation is used to clculate blood flow?
POISEUILLE’S LAW
Change in pressure/Resistance = Blood flow
What is the compensation result of hypoxia in the heart?
Vasodilation
What mediates Vasodilation in the coronary vessels in response to Hypoxia?
Adenosine
What is the vascular response in the lungs in response to hypoxia?
Vasoconstriction
What is Recruitment in Passive regulation of pulmonary regulation?
Opening of previously closed capillaries
What is Distention in Passive regulation of pulmonary regulation?
Accomodation of increased blood volume
What are the causes of alveolar hypoxia?
Airway obstruction
High altitude
Acute lung damage
COPD
