Function of the CVS Flashcards
What type of system is the CVS?
Bulk flow
What 4 things is the CVS responsible for getting around the body?
- O2 and CO2
- Nutrients
- Metabolites
- Hormones
What homeostatic aspect is regulated by the CVS?
Heat
In what ways is the CVS flexible?
- Pump output can vary
- Vessels can redirect blood
- Vessels can store blood
Describe the structure of the largest vessels of the CVS?
- Exist in series like an electrical circuit
- Output is equal
How do vascular beds exist with reference to eachother?
In a parallel circuit
What can occur to allow some beds to get more blood than others?
Regional redirection (vaso dilation/constriction in some vessels)
Why are the hypothalamas and anterior pituitary gland in series and not parallel?
- Blood travels through the hypothalamus first
- Picks up hormone secretions that work directly on the pituitary
What is the hierarchal order of organs by their O2
used?
Abdominal Organs
30%
Skeletal Muscles
20%
Brain
18%
Other
14%
Heart
10%
Kidney
6%
Skin
2%
What is the hierarchal order of organs by their cardiac output used?
Abdominal Organs
24%
Skeletal Muscles
20%
Brain
13%
Other
10%
Heart
4%
Kidney
20%
Skin
9%
What is the equation for pressure difference?
Pressure difference = mean arterial pressure - central venous pressure
What happens to flow when pressure increases?
Flow increases
What is the equation for flow?
Flow = change in pressure/resistance
What effect does radius of vessel have on the resistance?
Radius^4 so has a huge effect
What do arterioles act as by controlling resistance through radius?
Taps to each organ vascular bed