CVS Session 1- Intro To The CVS Flashcards
How does 98% of exchange between capillaries and tissues occur?
Via diffusion
What is the purpose of the CVS?
To supply all cells in the body with their metabolic needs.
Which two molecules can diffuse straight through the lipid bilayer?
Oxygen and carbon dioxide.
Which 3 molecules are hydrophilic and therefore travel down a concentration gradient and diffuse through small pores in capillaries?
Lactate, glucose, amino acids.
What three factors does the rate of diffusion depend on?
- diffusion resistance
- area
- concentration gradient.
The greater the conc. gradient the ………… The rate of diffusion.
Faster
The greater the number of capillaries the ………….the area and the ………… The rate of diffusion.
Greater
Greater
What is the diffusion resistance dependent on? (3)
The nature of the barrier
The nature of the molecule
The path length
What is the min and max blood flow in the brain and is there a change?
750ml/min (0.75l/min)
No
What is the min and max blood flow to the heart. Is there a change?
Min- 300ml/min
Max- 1200ml/min
Yes- can increase according to demand.
What is the min and max blood flow to the kidneys and is there a change?
1200ml/min
No because the kidneys require a constant perfusion in order to carry out their function.
What is the min and max blood flow to the gut and liver and is there a change?
Min- 1400ml/min
Max- 2400ml/min
It can increase when digestion is required.
What is the min and max blood flow to the skin and is there a change?
Min- 200ml/min
Max- 2500ml/min
Yes, changes according to thermoregulation
What is the min and max blood flow to muscle and is there a change?
Min- 1000ml/min
Max- 16000ml/min
Yes it can change according to increased exercise.
What is the average cardiac output at rest and during exercise of a 70kg man?
Rest- 5L/min
Exercise- 25L/min
