Cardiovascular system 8 Flashcards
Why do the arteries have high blood pressure
To be able to drive the blood around.
Gives free control of where the flow is moving
Is the flow in equal to the flow out
Yes
How is cardiac output distributed to all organs
Has multiple branches - think of it as a series of mini circuits making up one big one circuit
What does the circuit being parallel mean for blood flow
It means that you no longer need to have equal flow to different organs
What is the flow to organs like at rest
Fairly even flow to each organ
What is the flow to organs like with light and heavy exercise
Increased overall blood flow by 80%
Increase flow to; Heart, skin and muscles
Decrease flow to; Kidney, abdominal viscera (stomach) and other issue
What is the difference in flow between light and heavy exercise
Both change the flow to organs in the same way but to a larger degree when it comes to heavy exercise
Does blood flow to the brain change
No. The brain is always running at a high metabolic rate and doesn’t change it’s need when exercising.
How is MAP controlled during exercise
When Cardiac Output (CO) increases, the Total Peripheral Resistance (TPR)must decrease in order to keep a constant MAP
How does resistance change in individual branches
When flow needs to increase (in muscle, heart, skin) resistance must decrease
When flow needs to decrease (in kidneys, intestines, spleen etc.) resistance must increase
How is resistance controlled
The changing of the luminal radius (inside of vessel)
What are resistance vessels called
arterioles
What is the equation for resistance
R = 1/r^4
Inversely related, when r increases R will decrease
What is the rule of 16
When the radius changes by a factor of 2 the resistance will change by a factor of 16
What is vasodilation
When the diameter of a vessel increases (dilation), flow and supply also increases
