mass transport

Question 1

basic description of oxygen transport in blood

Answer 1

-at a high partial pressure oxygen associates with haemoglobin
- where it binds to haemoglobins haem group (Fe), enabling oxygen to be transported
- at a low partial pressure oxygen disscoiates from haemoglobin

Question 2

features of capillaries

Answer 2

• one cell thick –> short diff distance
• large number of capillaries –> large S.A
• small diameter –> large S.A/short diff distance.
• permeable wall –> fast rate of diffusion

Question 2

how does smoking lead to coronary h.d

Answer 2

-causes fatty deposits to build up in coronary arteries
- causes coronary arteries to narrow
- reduces blood supply to heart muscle

Question 2

why sickle cell diseas result in tiredness

Answer 2

-haemoglobin 3 shape altered
- therefore 4 shape is different so whole shape altered
- soo sickle cells cannot transport as efffciently as normal
- block narrow blood vessels
- less oxygen dissociates at respiring tissues
- less aerobic respiration therfore less ATP produced for respiration.

Question 3

adaptations of arteries

Answer 3

• thick wall –> prevents artery from bursting under hi pressure
• thick muscle layer / narrow lumen –> maintain hi blood pressure
• elastic tissue to stretch and recoil –> maintain blood flow
• smooth endothelium –> reduces friction

Question 4

how do arteries reduce blood flow

Answer 4

• smooth muscle
• muscle contracts and relaxes
• lumen diameter changes
• smaller/narrower lumen reduces blood flow

Question 5

steps of cardiac cycle

Answer 5

diastole -
atrial + ventricular muscles are relaxed (blood flows in)
atrial systole -
atria contract (AV valves open)
*short delay *ventricular systole -ventricles contract AV valves close and SL valves open