2023 Flashcards
Biological rhythms are influenced by endogenous pacemakers and exogenous zeitgebers.
0 7 Outline the difference between endogenous pacemakers and exogenous zeitgebers.
Use examples in your answer.
Marks for this question: AO1 = 2
2 marks for a clear outline with appropriate use of examples.
1 mark for a limited/muddled outline with inappropriate/no use of examples.
Possible content:
* endogenous pacemakers are internal whereas exogenous zeitgebers are external
* endogenous pacemakers are body clocks which regulate biological rhythm whereas exogenous
zeitgebers are cues that entrain our biological rhythms
* examples used to illustrate the difference between the two influencers, eg the effects of the SCN
(endogenous pacemaker) as opposed to light (exogenous zeitgeber).
Credit other relevant material.
Xavier was cycling to school when he fell off his bike into the road. A teacher saw a car
swerve, narrowly missing Xavier. The teacher checked Xavier was safe and asked him
what had happened.
Xavier could hardly speak; his heart was pounding, and his mouth was dry. He felt sick
and his hands were shaking. It took Xavier 20 minutes to feel calm again.
0 8 Outline the fight or flight response and use this to explain what Xavier was experiencing.
Possible content:
* the fight/flight response is generated by the sympathetic branch of the ANS
* the hypothalamus stimulates the SNS
* SNS stimulates the adrenal medulla to release adrenaline into the blood stream/endocrine system and
noradrenaline is released
* generalised effects of adrenaline such as increased breathing rate, sweating, pupil dilation, etc
* adrenaline inhibits saliva production, which may explain Xavier’s dry mouth
* Xavier’s shaky hands may be caused by adrenaline as adrenaline increases muscle tension, causes
an increase in heart rate (Xavier’s heart was pounding)/increases blood flow to muscles (which can
cause limbs to shake) and adrenaline stimulates glucose to be released/increases blood sugar levels,
providing more muscle fuel
* digestion is inhibited during SNS arousal, which may explain why Xavier felt sick
* once the stressor is gone the PNS acts to dampen the stress response and return the heart/breathing
rate to resting levels/initiate digestion, etc, this may explain why after 20 mins Xavier calmed down.
Credit other relevant material.
