Lecture 11 Flashcards
What is the pressure versus flow equation?
Q = P / R
Why is it important to maintain high arterial blood pressure?
To be able to drive blood around the system and to have control of where are at what pressure blood flows
What is the essential relationship between the hearts left and right pump?
Equal flow throughout both circuts
What is the design of systemic circulation?
Parallel
What is the design of pulmonary circulation?
Series
What are the features of the parallel design of circulation?
Continual branching of arterial networks and division of blood among the regional circulations
Is the distribution of cardiac output fixed or dynamic?
Dynamic, changed upon bodily needs
Why does blood flow increase to some regions and decrease to others during exercise?
To maintain metabolic needs in high-energy places
During exercise, where is the flow of blood increased?
Muscle, heart, skin
During exercise, where is the flow of blood decreased?
GI tract, kidneys
During exercise, where is the flow of blood consistant?
Brain
What is MAP?
Mean arterial pressure
What is CO?
Cardiac output
What is TPR?
Total peripheral resistance
How is MAP controlled during exercise?
Increased CO and decreased TPR in order to keep MAP constant
What is the relationship between CO and TPR
Inversely proportional
What is the total change in resistance when the body is undergoing exercise?
Increased
How is resistance controlled?
By the smooth muscle precapillary sphincters which constrict to increase resistance and dilate to decrease resistance
If the resistance is increased, where is the blood skipping?
The capillary (exchange) beds
If the resistance is increased, through what channel is the blood flowing between arterioles and venules?
Thoroughfare channel
What is the relationship between resistance and radius?
Resistance is proportional to 1 / r^4
What is the luminal radius?
Radius within the lumen of a blood vessel
What is the luminal space?
The space within the lumen of a blood vessel
If the radius is increased by a factor of 2 what happens to the resistance?
It is decreased by a factor of 16
If the radius if decreased by a factor of 2 what happens to the resistance?
It is increased by a factor of 16
What is vasodialation?
Increase in radius of a arterial vessel therefore leading to a decrease in resistance
What is vasoconstriction?
Decrease in radius of a arterial vessel therefore leading to an increase in resistance
