Question 18N.3.SL.TZ0.19
| Date | November 2018 | Marks available | [Maximum mark: 7] | Reference code | 18N.3.SL.TZ0.19 |
| Level | SL | Paper | 3 | Time zone | TZ0 |
| Command term | Explain, Identify, Outline | Question number | 19 | Adapted from | N/A |
The scanning electron micrograph (SEM) shows a cell in the liver responsible for the breakdown of erythrocytes. The cells are found in the lining of the sinusoid walls.
Identify cell X shown in the diagram.
[1]
Kupffer cell ✔
Outline the role of the cell in recycling iron in the body.
[2]
a. ingests red blood cells by phagocytosis ✔
b. splits the hemoglobin into heme «and globin»
OR
heme group broken down into iron «and bilirubin»
OR
hemoglobin broken down into iron ✔
c. releases iron for transport ✔
Explain reasons for the dual blood supply to the liver.
[4]
a. the dual supply is the hepatic artery and the hepatic portal vein ✔
Both needed
b. blood in «hepatic» artery provides oxygen to the liver «tissues» ✔
c. the «hepatic portal» vein carries blood from the gastrointestinal tract/intestines ✔
d. the «hepatic portal» vein carries blood rich in nutrients ✔
e. this allows the nutrients to be stored/processed
OR
sugar/glucose/glycogen is stored and released in response to hormones ✔
f. prevents osmotic imbalance due to absorbed nutrients in the blood ✔
