Transport in Humans
November 2013
1ai P – right atrium
Q – bicuspid valve
1b
Oxygenated blood from the lungs is carried to the heart via the pulmonary vein;
Blood enters the left atrium, which contracts to pump blood into the left ventricle;
The bicuspid valve opens and blood flows into the left ventricle, which contracts, to
pump blood into the aorta;
The bicuspid valve closes and the semi-lunar valves of the aorta open;
When the pressure in the ventricle falls below that of the aorta, the semi-lunar
valves close to prevent the backflow of blood back into the left ventricle;
1ci
1cii
0.3 seconds
Line 2
November 2012
5ai A – Red blood cell
5aii
B – Tissue fluid
Arrow must extend from RBC to the body cell
5aiii C is a white blood cell.
White blood cells like lymphocytes produce antibodies;
White blood cells like phagocytes ingest and digest foreign particles and bacteria;
5b
Group A – yes
Group B – no
Group O -- no
November 2010
1a
A – aorta
B – left ventricle
1b
(Coronary artery) Transports oxygenated blood and nutrients like glucose to the
cardiac muscle;
For respiration to release energy for muscle contraction so that the heart can pump
blood;
1cii
Allows more oxygen and glucose to be transported to the heart muscle per unit time;
So that aerobic respiration can occur at a faster rate in heart muscle cells to release
more energy for muscle contraction for the heart to pump oxygenated blood at a
faster rate to the muscles of the body;
(so that aerobic respiration can in turn take place at a faster rate in muscle cells to
release energy to meet the energy demands for vigorous muscle contraction;
*this question is about blood flow, not about why breathing rate increases, so no
need to introduce the idea that high CO2 concentration is a stimulus for breathing
and that increased rate of blood flow allows CO2 to be removed at a faster rate.