The diagram shows the internal structure of a human heart viewed from the front and its associated blood vessels. [Figure 6.1: Internal structure of a human heart viewed from the front, with blood vessel P, structure Q, and structure R labeled.]

Mark scheme

Marking points from the official mark scheme (May/June 2019). The mark or mark type is shown in brackets.

1. [3] blood vessel P: pulmonary vein ;
2. [3] blood vessel P: oxygenated blood;
3. [3] blood vessel P: from lungs / to heart / to left atrium ;
4. [3] structure Q: left ventricle / muscle;
5. [3] structure Q: pumps / contracts / pushes blood ;
6. [3] structure Q: high pressure ;
7. [3] structure Q: blood to + body / aorta;
8. [4] structure R: valve;
9. [4] structure R: atrioventricular / tricuspid;
10. [4] structure R: opens + blood into right ventricle ;
11. [4] structure R: closes + blood into pulmonary artery / blood to lungs ;
12. [4] structure R: prevent backflow AW + of blood ;
13. [4] structure R: (prevents backflow) into right atrium ;