Session 1- Introduction To The Unit

Question 1

Be aware of different imaging techniques that can be used to asses cardia structure and functioning.

Answer 1

X-rays
CT scans
MRI
Ultrasound

Question 2

Calculate the cardiac/thoracic ratio and suggest what an increased ratio might mean?

Answer 2

Ratio of transverse cardia diameter/ internal thoracic diameter
Ratio should be <50%

Question 3

Explain how blood flow is controlled and how appropriate blood flow to different tissues of the body is achieved?

Answer 3

Peripheral resistance- Happens at the arterioles. Decrease resistance, more blood flowing/ diffusion
Vasodilation/Vasocontriction
Blood pressure
Pre-capillary sphincters that control the flow depending on the body’s needs.

Question 4

Describe the constituents of whole blood and the effect of
changing cell number or protein content on viscosity and some conditions which affect the cell count or protein content of blood.

Answer 4

RBC,WBC’s,Platelets
Increasing cell number/ protein content, it will increase viscosity
Extremes of blood conditions- increase in blood viscosity
Due to inflammation we get a change in plasma viscosity arising from acute phase proteins- CRP, fibrinogen,compliment

Question 5

Be able to describe how blood flows as a fluid, yet is composed
of a mixture of cells and plasma

Answer 5

Plasma is a liquid and it carries the cells.

Plasma= main component of the blood

Question 6

Explain the term flow and the factors affecting flow of blood
through vessels

Answer 6

Flow is the movement of blood
Factors affecting:
Resistance
Pressure
Conductance
Strength of the myocardium- how hard the heart pumps 
Stroke volume

Question 7

Explain the term velocity and the factors affecting velocity of
blood

Answer 7

Velocity: is the distance fluid moves in a given time

Inversely proportional to radius squared

Question 8

• Describe how arterial blood pressure is measured and what
would be heard in a stethoscope as the pressure in the cuff is
changed

Answer 8

Arterial blood pressure is measured via sphygmomanometer cuff and stethoscope.
Tighten the cuff a bit to about 150/160mmHg, release the cuff and start counting from when you first hear the turbulent flow and record the systolic. Then once the turbulent flow/sound cannot be heard, record the number shown as the diastolic.
Make sure the cuff is in line with the brachial artery

Question 9

What is the pulse pressure?

Answer 9

Systolic blood pressure- diastolic pressure

Question 10

Estimate the mean arterial pressure?

Answer 10

Diastolic pressure+ (pulse pressure/3)

Question 11

Describe factors that will effect venous pressure and factors
that will affect arterial pressure

Answer 11

Factors affecting venous pressure- Cardiac output, peripheral resistance, stroke volume
Factors affecting arterial pressure- Cardiac output, peripheral resistance, vasodilation, vasoconstriction