S3 Haemodynamics

Question 1

Define Blood serum

Answer 1

Plasma without no clotting factors present

Question 2

Name a condition linked with changes in blood viscosity

Answer 2

Polycythaemia (RBC)
Thrombocynthaemia (Platelets)
Leukaemia (WBC)

Question 3

What is Haemodynamics

Answer 3

Factors that govern the movement of blood.

Question 4

Name three types of blood flow

Answer 4

Laminar- smooth, energy maintaining (typical of arteries, arteriolar, venues and veins)

Tubular- disorganised and energy is lost. Pressure increase beyond which flow can match it linearly (ventricles, stenosed arteries and changing direction of vessels [branching])

Single-file (bolus)

Question 5

How do you calculate Mean Arterial Blood Pressure (MABP)?

Answer 5

MABP = Cardiac Output x Total Peripheral Resistance

Question 6

What is pulse pressure?

Answer 6

Difference between Systolic and Diastolic pressure (SBP-DBP)

Question 7

What are the primary factors of Resistance to flow?

Answer 7

Diameter

Length of vessel

Viscosity

Question 8

Which primary factor has the most affect on resistance?

Answer 8

Diameter-Most impact on resistance due to the fourth power of the radius in the equation: R=(8vL)/([pi]r^4)

Question 9

What are Korotkoff sounds?

Answer 9

Using a BP cuff, changes from Laminar to turbulent flow create a sound which can be used to estimate blood pressure.

Question 10

What are the effects of gravity on blood pressure?

Answer 10

When pressure is taken below the heart—> measurement is greater (taken above —> lower)

Effect of gravity maintains a pressure gradient to allow flow from heart to foot when standing.

Pooling of blood below the level of the heart upon standing in the venous system.

Postural Hypotension- Dizziness upon standing, decreased SV and transient arterial hypotension.

Question 11

What is the equation for:
Pulse Pressure
MAP
Cardiac output
MAP

Answer 11

PP= SBP-DBP

MAP=DBP+[(SAP-DBP)/3]= DBP+1/3PP

CO=HR x SV

MAP= CO x TPR