Question 18N.2.SL.TZ0.4
| Date | November 2018 | Marks available | [Maximum mark: 7] | Reference code | 18N.2.SL.TZ0.4 |
| Level | SL | Paper | 2 | Time zone | TZ0 |
| Command term | Describe, Explain, Label | Question number | 4 | Adapted from | N/A |
Label X and Y on the diagram of the heart.
[2]
X: pulmonary artery ✔
Y: left atrium ✔
Accept auricle
Explain how the circulatory system is able to transport the blood under high pressure from the heart to the rest of the body.
[3]
a. contraction of ventricle creates high pressure ✔
b. blood at high pressure is carried out of the heart through arteries ✔
c. thick muscular walls of arteries resist pressure/prevent leaks ✔
d. elastic recoil of arterial walls helps to push blood ✔
e. narrow lumen of arteries maintain pressure ✔
Features require an explanation, a list is inadequate
The heart responds quickly to physical activity. Describe how heart rate is controlled to meet the increased circulatory demands.
[2]
a. nerve impulse from medulla/brain acts on heart/right atrium ✔
b. pacemaker/sinoatrial node/SAN increases/controls contraction of heart ✔
c. epinephrine/adrenaline «rapidly» increases heart rate ✔