Cardiovascular: Session 1 Flashcards
What is the function of the cardiovascular system?
Pumps blood around the body which carries oxygen and nutrients to capillaries. At capillaries diffusion can take place.
3 factors affecting diffusion in capillaries?
Area available for exchange
Diffusion resistance
Concentration gradient
What is the rate of blood flow known as?
Perfusion rate
What is the total blood flow at rest? And maximum when active?
5.0 at rest
25 when active
What are the layers of the pericardial sac?
Fibrous layer
Parietal layer
Visceral layer
What is the purpose of the pericardial sac?
Allows heart to move freely by providing lubrication via fluid in the pericardial cavity. Keeps the heart in place.
What is cardiac tamponade and the cause?
Excess fluid can build up in pericardium. This leads to compression of heart due to the inextensible fibrous layer. This means heart cannot fill in diastole due to pressure.
What is pericardiocentesis?
Needle to the sac to remove the fluid.
Describe the coronary arteries?
End arteries
Vital to supply well oxygenated blood to myocardium
What is fluid collected from clotted blood called?
Serum
What is fluid called from unclotted blood called?
Plasma
What protein is used to measure inflammation?
C-reactive protein
What can minor changes in plasma viscosity be used to measure?
Inflammatory response
How does fluid move along a pressure gradient?
moves from regions of high pressure to regions of low pressure
What is turbulent flow?
blood flow in all directions in the vessel continually mixing within the vessels
What causes turbulent flow?
- rate of blood flow becomes too great (anaemia)
- passes an obstruction
- makes a sharp turn
- when it passes over a rough surface
- increases resistance to blood flow
What is stenosis?(in artery)
Narrowing of the vessel
What is critical ischaemia?(in artery)
A stenosis followed by a stenosis so reduces pressure. This happens in the leg
How can stenosis cause an aneurysm?
Blood flow energy is increased due to increased velocity. Causes the blood vessels beyond to stretch.
what is pulse pressure?
peak systolic pressure - end diastolic pressure
What is ‘mean arterial pressure’?
Diastolic pressure + 1/3 of the pulse pressure. Falling below 70 mmhg then organ perfusion is impaired.(not really used clinically)
When does retrograde flow occur?
When the peripheral resistance is high - blood bounces back.
What is pulse?
A shockwave that arrives slightly before the blood itself.
What is bounding pulse?
A strong pulse
