

The diagram above shows part of a capillary network and surrounding tissues.
State three ways in which the blood at Y differs from the blood at X other than the concentration of carbon dioxide.


Important Questions on Transport in Mammals
An enzyme in red blood cells catalyses the reaction between carbon dioxide and water as the blood flows through the respiring tissues.
Explain the significance of this reaction in the transport of carbon dioxide.

The graph below shows the effect of increasing the effect of carbon dioxide concentration.
State the percentage saturation of haemoglobin with oxygen at a partial pressure of 5 kPa of oxygen when the partial pressure of carbon dioxide is:
- 1.0kPa
- 1.5 kPa

Mammals have a closed double circulation. What is meant by the term double circulation.

Explain why the wall of artery is thicker than the vein?

Suggest one role for the precapillary sphincter shown in the figure.

The given image shows circulation in mammalian tissue.
With reference to this figure, describe the role of capillaries in the formation of tissue fluid.

The given figure shows the pressure changes in the left atrium, left ventricle and aorta throughout two cardiac cycles.
How long does one cardiac cycle last?

The given figure shows the pressure changes in the left atrium, left ventricle and aorta throughout two cardiac cycles.
What is the heart rate represented on this graph in beats per minute?
