Flashcards in CVS - Intro To CVS Deck (12)
Why do single-celled organisms not require a cardiovascular system to get O2 and nutrients?
They can get them directly by diffusion from the environment.
Give some factors that affect the rate of diffusion.
- area available for exchange
- diffusion 'resistance', eg nature of molecule
- concentration gradient
Will a tissue which is very metabolically active have a high or low capillary density?
A high capillary density, allowing a large area for exchange.
Will the concentration of a substance used by tissues (eg oxygen) be higher or lower in capillary blood than arterial blood?
Lower. The size of the difference depends on the rate of use by the tissue and the rate of blood flow through the capillary bed.
What is the 'perfusion rate'?
The rate of blood flow through tissues.
Does blood flow to the brain change during exercise?
No, it stays constantly high
What is total blood flow at rest?
About 5 litres per minute
What can total blood flow rise to during exercise?
It can reach 25 litres per minute.
What are the layers of the pericardium?
- fibrous layer
- parietal (outer serous) layer
- pericardial cavity (not technically a layer, the space contains pericardial fluid)
- visceral (inner serous) layer
What is cardiac tamponade?
Fluid in the pericardium builds up and results in compression of the heart.
What is pericardiocentesis?
A procedure where fluid is aspirated from the pericardium.