Case 3 - Pulmonary circulation and disease

Question 1

what’s Systemic Circulation?

Answer 1

Systemic Circulation - it’s related to the left heart
Contraction of the left ventricle pumps blood into the Aorta

Question 2

what’s Pulmonary Circulation?

Answer 2

Pulmonary Circulation - it’s related to the right heart
Contraction of right ventricle pumps blood
into the pulmonary arteries.

Question 3

what are Systemic arteries like?

Answer 3

Systemic arteries: moderate size, thick muscular walls

Question 4

what are Pulmonary arteries like?

Answer 4

Pulmonary arteries: thin elastic walls, large diameter

Question 5

Special Anatomical features of pulmonary circulation?

Answer 5

• The pulmonary arteries are thin walled. They have far less smooth muscle than systemic arteries.
• pulmonary arteries have a larger diameter than systemic arteries.
• Vessels are highly distensible (easily stretched/expanded) and compressible
• Because of high compliance, pulmonary arteries stretch during systole - this smooths the blood flow through the lungs

Question 6

Is the cardiac output the same or different on the left and right sides of the heart?

Answer 6

The cardiac output is the same on the left and right sides of heart

Question 7

why is pulmonary vascular resistance lower than systemic vascular resistance

Answer 7

because pulmonary arterial pressure is much lower than systemic arterial pressure, then pulmonary vascular resistance must also be much lower than systemic vascular resistance

Question 8

what is The mean pulmonary artery pressure

Answer 8

The mean pulmonary artery pressure is low (15mmHg).

Question 9

what does hypoxia cause in the pulmonary circulation and in the systemic circulation?

Answer 9

hypoxia causes vasoconstriction in pulmonary circulation
hypoxia causes vasodilation in systemic circulation