pmt transport in animals

Question 1

how does the artery withstand pressure

Answer 1

-wall is thick
-thick layer of collagen
-wall of collagen provides strength
-endothelium folded
-no damage to endothelium/ artery wall as it stretches

Question 2

how does the artery maintain pressure

Answer 2

-thick layer of elastic tissues/ fibres
- to cause recoil/ return to og size
-thick layer of smooth muscle
-narrows/ constricts lumen/artery

Question 3

why is the ventricle thicker than the atrium (left)

Answer 3

-more muscle to create more force
- needs to create a higher pressure
-push blood against greater resistance/ friction
-left v pumps blood further/ systemic circulation

Question 4

how do pressure changes in the heart bring about the closure of atrio ventricular valve

Answer 4

-ventricular systole
-raises ventricular pressure
-higher than atrial pressure

Question 5

outline the benefits oof the bhor shift to actively respiring tissue.

Answer 5

• actively respiring tissues require more oxygen
• for aerobic respiration
  -actively respiring tissues produce more CO2
  -Hemoglobin involved in transport of CO2
  -less haemoglobin available to combine with O2
  -Bhr shift causes more oxygen to be released