- (i)What is the average resting rate of the human heart in beats per minute?
(ii) State one factor that decreases heart rate and one factor that increases it.
(b) The diagram shows a vertical section through the human heart.
(i) Name the parts A, B, C, D, E and F.
(ii) To where does E carry blood?
(iii) What is the function of B?
(iv) Name the artery that supplies the heart muscle with blood. (27)
(c) (i) Name the liquid part of blood.
(ii) Name two substances that are dissolved in the liquid part of blood.
(iii) State one function of the liquid part of blood.
(iv) Blood contains red cells and white cells. State one function for each of these.
(v) Name two common blood-grouping systems.