Circulatory System

Question 1

Pulmonary Circulation

Answer 1

Pulmonary artery takes deoxygenated blood to lungs to drop off CO2 and pick up O2 and return to the heart through pulmonary veins

Question 2

Systemic Circulation

Answer 2

Aorta takes oxygenated blood around body to tissues and deoxygenated blood returns to heart through superior and inferior vena cava

Question 3

Coronary Circulation

Answer 3

Circulation of blood in the blood vessels of the heart muscle (myocardium) that deliver, oxygen-rich blood to the heart itself, so it can function

Question 4

Heart Characteristics

Answer 4

• About size of a clenched fist

- Has three layers (endocardium, myocardium and pericardium)

Question 5

Arteries: Function

Answer 5

• Take blood away from the heart
• Always carry oxygenated blood, EXCEPT pulmonary artery (deoxygenated blood to lungs)
• deliver oxygen and nutrients to tissues
• High pressure vessels

Question 6

Arteries: Structure

Answer 6

• Small lumen and thick muscle layer (high BP)
• Elastic and collagen fibres (push blood)
• Fibrous tissue support and hold artery in place

Question 7

Arterioles: Function

Answer 7

• Very small arterioles
• Change their diameter to BP and blood flow to different tissues
• Constrict = increase BP upstream, decrease BP downstream

Question 8

Arterioles: Structure

Answer 8

• Smooth muscle: contracts and allow vessel to constrict, then dilates when it relaxes

Question 9

Capillaries: Function

Answer 9

• Allow substances to diffuse out of blood into tissue and into blood from tissues

Question 10

Capillaries: Structure

Answer 10

• Single layer of epithelial cells: easy for oxygen and nutrients to diffuse through
• Some have fenestration (holes) to facilitate diffusion

Question 11

Veins: Function

Answer 11

• Veins always return blood TO the heart
• Always carry deoxygenated blood EXCEPT pulmonary veins (oxygenated blood from lungs to heart)
• Deliver wastes and deoxygenated blood to heart
• Lower pressure vessels, but hold much more blood than arteries because they expand easy

Question 12

Veins: Structure

Answer 12

• Thin walls with few elastic fibres
• Large lumen for easy blood flow
• No contractions by vessels, thus:
  > Veins are located near muscles to produce compression flow
  > Veins have valve to prevent back flow of blood