vascular system

Question 1

describe arteries

Answer 1

• carry blood away from the heart at a high pressure
• thick elastic walls, small lumen

Question 2

describe capillaries

Answer 2

• brings blood to tissues where gas exchange occurs
• very thin walls to allow for gaseous exchange

Question 3

describe veins

Answer 3

• carry blood to the heart at a low pressure
• thin walls large lumen

Question 4

define: venous return

Answer 4

the return of blood to the heart

Question 5

what are the venous return mechanisms

Answer 5

• pocket valves to prevent backflow
• muscle pump
• gravity
• smooth muscle: helps push blood through veins toward the heart
• respiratory pump: as breathing gets faster/deeper, pressure changes in thorax and abdomen helping to force blood to the heart

Question 6

what do the receptors do and detect|?

what does the vcc then do?

Answer 6

tell the body is exercising by:

• baroreceptors: detect increase in blood pressure
• chemoreceptors: detect increase in CO2 and lactic acid
• proprioreceptors: detect movement

the vcc then responds by sending messages to redistribute the blood

Question 7

effect on vcc on organs and muscles

Answer 7

vcc responds by sending messages to

• vasodialate the arterioles and pre-capillary sphincters that supply the muscles
• and vasoconstricting the arterioles and pre-capillary sphincters that supply the organs