blood vessels

Question 1

Describe the structure and function of arteries, arterioles, capillaries, venules and veins?

Answer 1

arteries, thick and highly elastic walls, large radii

arterioles, highly muscular, innervated walls, small radii,

capillaries, thin walled, permeable, high cross section,

veins, thin walled, highly distensible, large radii.

venules, small veins, formed by merging of multiple capillaries, collect deoxygenated blood and waste blood to be re-oxygenated

veins, made of multiple venules,

Question 2

Explain the mechanisms that regulate blood flow through arteries, capillaries and veins

Answer 2

tunica media contains high proportion of smooth muscle

• distributes and regulates blood flow to required areas, can constrict and dilate
• superficial muscular arteries form pressure points to control bleeding.

Question 3

Explain the relationship between haemodynamic variables i.e. blood flow, pressure and resistance?

Answer 3

resistance increases pressure decreasing blood flow

Question 4

Describe the determinants of vascular and total peripheral resistance?

Answer 4

vascular resistance the forces opposing blood flow
- friction between blood and vessel walls. determined by length and diameter

peripheral resistance
- reflects factors of vascular resistance, blood viscosity and turbulence

Question 5

Describe the relationship among vessel diameter, cross-sectional area, blood pressure and blood velocity

Answer 5

as vessel diameter decreases, cross sectional area decreases, blood pressure increases, blood velocity increases as cross sectional area decreases

Question 6

Discuss the movement of fluid between capillaries and interstitial fluid

Answer 6

osmosis