Circulatory System

Question 1

Arteries

Answer 1

thick muscular walls
relatively small lumen
elastic tissue for stretch and recoil - maintains high pressure
endothelium is folded allowing more stretch
all carry oxygenated blood except from pulmonary arteries
renal artery
hepatic artery
pulmonary artery
aorta

Question 2

Veins

Answer 2

wider lumen
very little elastic and muscle tissue (lower pressure)
valves prevent backflow
blood flow helped by contracting muscles
All carry deoxygenated except pulmonary veins
hepatic (portal) vein
renal vein
vena cava
pulmonary vein

Question 3

Capillaries

Answer 3

one cell thick and very near cells in exchange tissues - short diffusion pathway
many of them = large surface area

Question 4

Tissue Fluid formation

Answer 4

hydrostatic pressure at start of capillary bed is greater than in tissue fluid
fluid forced out of capillaries and into spaces around the cells forming tissue fluid
hydrostatic pressure in capillaries reduced at the venule end
increased conc. plasma proteins and fluid loss results in more negative water potential at the venule end than tissue fluid
TF water re enters the capillaries from tissue fluid at venule end
excess is drained into lymphatic system and is bypassed back into circulatory system