Circulation

Question 1

Relationship between cross-sectional area and blood pressure

Answer 1

• blood pressure inversely proportional to lumen but remains constant as cross-sectional area decreases

Question 2

Relationship between cross-sectional area and blood speed

Answer 2

Increases as lumen decreases in veins

Question 3

Describe the movement of substances between blood in capillaries and tissue fluids

Answer 3

• oxygen diffuses from blood to tissue
• across capillary membrane
• down the conc. gradient
• pressure gradient forces out water and solutes

Question 4

Role of arterioles in maintaining body heat during cold temps

Answer 4

• vasoconstriction
• prevents heat leaving the body through radiation/conduction/convection
• muscles in arterioles contract

Question 5

Explain the structure of an artery

Answer 5

• thick wall to withstand blood pressure
• narrow lumen to maintain blood pressure
• muscular tissues for vasoconstriction/vasodilation
• elastic tissue that recoils to smooth out flow
• fibrous tissue that maintains the shape to prevent bursting