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Question 17N.3.SL.TZ0.16c

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Date November 2017 Marks available [Maximum mark: 2] Reference code 17N.3.SL.TZ0.16c
Level SL Paper 3 Time zone TZ0
Command term Outline Question number c Adapted from N/A
c.
[Maximum mark: 2]
17N.3.SL.TZ0.16c

The diagram shows changes in the pressure and volume of the left ventricle during normal heartbeat. The phonocardiogram records heart sounds during the cardiac cycle.

[Source: Wiggers, Carl J. 1923. Modern Aspects of the Circulation in Health and Disease, 2nd ed. Philadelphia: Lea & Febiger, p. 97.]

(c)

Outline reasons for fitting an artificial cardiac pacemaker.

[2]

Markscheme

a. required when rate of heartbeat/heart contraction is too slow/irregular

b. produces electrical impulse that stimulates heartbeat/heart contraction

c. needed when SA node is defective

Accept “regulate the heartbeat” for marking point a

[Max 2 Marks]

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