Session 5 - Haemodynamics Flashcards
What is plasma?
Fluid collected from unclotted blood
Give an example of an anticoagulant
Heparin
What is serum
Fluid collected from clotted blood. It is plasma without the clotting factors
What is peripheral resistance
The resistance to blood flow in the arteries
What increases peripheral resistance
Contraction of the arteries
What does an increased blood viscosity result in
Sludging of blood in the peripheries
Why does an increased blood viscosity result in sludging of blood?
There is increased resistance to flow so the heart cant pump the blood as powerfully
What is the most common cause of an increase in blood viscosity
Multiple myeloma
What is multiple myeloma
Cancer of the plasma cells resulting in an increase in the number of plasma cells and so blood viscosity
What is an increase in red blood cells known as
Polycythaemia
What is an increase in platelets known as
Thrombocythaemia
What is an increase in white cells known as
Leukaemia
What can minor changes in plasma viscosity be used to measure
Inflammation response
Minor changes in plasma viscosity are a result of an increase of what
Acute phase plasma proteins
Give 3 examples of acute phase plasma proteins
Complement factors, fibrinogen and c-reactive proteins
What is a turbulent blood flow
Where blood flows in all directions
Give 5 causes of turbulent blood flow
- Rate of blood flow is too great
- Blood passes an obstruction
- Blood makes a sharp turn
- When blood passes over a rough surface
- Increased resistance to flow
What is a sternosis
Obstruction
What is an occlusion
Blockage
True or false; blood normally has a turbulent flow
False - blood normally has a laminar flow
What is a laminar flow
Where blood flows in streamlines and in the same direction
Where is the greatest velocity of blood in laminar flow
In the centre as resistance increases at the edges due to contact between blood and the vessel wall giving a parabolic profile
What is haemodynamics
The effect pressure has on the flow of blood through vessels
What are the units for flow
Volume per units of time
What is pressure measured in
Pounds per square (psi)
What occurs during the systolic uptake
Pressure in the aorta increases as the left ventricles contract