Unit 1 Section 5: Blood Vessels

Question 1

Arteries

Answer 1

• carry blood from the heart to the rest of the body
• Thick muscular walls
• have elastic tissue to cope with Pressure
• the inner endothelium lining is folded allowing the artery to expand(also helps when under pressure)
• Generally carry oxygenated blood except for pulmonary
• branch into capillaries

Question 2

Capillaries

Answer 2

• Smallest blood vessels
• Thin one celled walls adapted for efficient diffusion
• connect to veins

Question 3

Veins

Answer 3

• take blood back to the heart
• wider than arteries
• very little elastic/muscle tissue
• contain valves to stop backward blood flow
• blood flow aided by muscles around the vein contracting
• Generally carry deoxygenated blood except for pulmonary

Question 4

Tissue Fluid

Answer 4

• surrounds cells in tissues
• made from substances that leave the blood e.g. Oxygen
• Cells take in oxygen and nutrients form the fluid and release metabolic waste into it
• In a capillary bed substances move into tissue fluid by Pressure filtration