CIRCULATION QUESTIONS

1.

This diagram shows a section through a human heart

(a)

Name the parts labelled A-H.

(8)

(b)

In which part of the heart is the SAN (pacemaker) located?

(1)

(c) State two ways in which blood leaving the left side of the heart is different from blood leaving the right side.

(2)

(d) Explain how blood is forced to flow in one direction only through the heart.

(2)