Date | May 2018 | Marks available | 3 | Reference code | 18M.3.HL.TZ1.20 |
Level | Higher level | Paper | Paper 3 | Time zone | Time zone 1 |
Command term | Explain | Question number | 20 | Adapted from | N/A |
Question
The diagram shows the liver and its main blood vessels.
[Source: VectorStock]
Label the hepatic portal vein bringing blood to the liver.
Outline the circulation of blood through liver tissue.
Explain the breakdown of hemoglobin in the liver.
Markscheme
[Source: VectorStock]
Accept the vessel labeled (hepatic portal vein) as it ends in the liver and does not continue. A label anywhere on the vessel or pointing to the arrow underneath it is acceptable.
a. hepatic artery carries oxygenated blood (from the aorta)
b. hepatic portal vein carries (deoxygenated) blood from digestive tract
c. blood from hepatic portal vein and hepatic artery mixes
d. flows through sinusoids
e. hepatic vein carries blood away from liver/to heart
a. hemoglobin absorbed by phagocytes/Kupffer cells
b. split into heme and globin
c. globin hydrolysed/broken down to amino acids
d. iron removed from heme group / heme broken down to form bilirubin/bile pigment