Lecture 1: Circulation and Haemodynamics

Question 1

What are arteries?

Answer 1

blood vessels that carry blood AWAY from the heart

- oxygen rich blood is pumped away from the heart in arteries

Question 2

What are veins ?

Answer 2

blood vessels that carry blood TOWARDS the heart

- oxygen poor blood moves towards the heart in viens

Question 3

Describe the chambers of the heart?

Answer 3

Four chambered heart

• The right and left atrium = smaller chambers which quickly put blood into the ventricles
• The right and left ventricles = larger chambers which pump the blood out of the heart

Question 4

What direction does blood flow in?

Answer 4

Blood flows in one direction

Question 5

How does blood flow through the pulmonary and systemic circuits?

Answer 5

• moves blood ‘IN SERIES’

- ensures that blood flows through the lungs then through the systemic circulation to all organs

Question 6

How does blood flow through the systemic circuits?

Answer 6

• lies ‘IN PARALLEL’ to each other.

- oxygenated blood is carried from the heart to the tissues and returns oxygenated blood back to the heart

Question 7

How is one way blood flow achieved?

Answer 7

1. Strutural = presence of unidirectional valves that prevent back flow
   e. g heart & venous valves
2. Pressure gradient = positive gradient from left to right side of the heart

Question 8

What are two important haemodynamic factors that affect blood flow?

Answer 8

Flow = pressure difference/Resistance

• blood flow is determined by pressure generated by the heart and the total resistance of the vessels
• a sufficient high arterial pressure is critical to enabling blood flow in the vascular system