Question
a. Outline the neural control of the process of swallowing. [3]
▶️Answer/Explanation
Markscheme
a. «usually» autonomic reflex
b. «usually» involuntary/automatic
OR
not controlled consciously
c. coordinated by medulla «oblongata»
d. can be voluntary/consciously controlled «by cerebral cortex»
Question
D-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), the two main psychoactive ingredients of the Cannabis sativa plant, have distinct symptomatic and behavioural effects. Functional magnetic resonance imaging (f MRI) was used in healthy volunteers to examine their effects on the parahippocampus, an area of the brain related to emotions and on the visual cortex. The effects are as shown.
a. Outline the benefits of using fMRI in this experiment. [2]
b. Compare and contrast the effects of THC and CBD on the areas of the brain studied. [3]
c. State the function of the visual cortex. [1]
▶️Answer/Explanation
Markscheme
a. «fMRI» allows imaging through magnetic resonance
b. to measure the amount of activity/blood flow in different parts of the brain
OR
to identify the parts of the brain that are activated
c. non-invasive/indirect observation/real time observation
a. THC causes a negative/inhibitory mean activation of parahippocampus whereas CBD causes a positive/excitatory one
OR
THC and CBD cause opposite effects on parahippocampus
b. both cause a positive/excitatory «mean activation» of the visual cortex
c. «magnitude» of mean activation of both ingredients is minute on parahippocampus compared to visual cortex/OWTTE
d. mean activation due to THC lower than CBD for both «parahippocampus and visual cortex»
OR
mean activation due to THC lower than placebo whereas higher for CBD for both
e. other valid comparison/contrast between the two drugs
processing visual information/signals from the optic nerve/OWTTE
Question
The drawing shows a vertical section through the brain.
a.i. Label the cerebellum on the diagram. [1]
a.ii. State a function of the cerebellum. [1]
b. On the diagram, label one named structure that produces hormones. [1]
c. Outline one method that can be used to investigate the function of different parts of the brain. [2]
▶️Answer/Explanation
Markscheme
label to cerebellum
controls/coordinates (motor) movements/balance
label to pituitary
OR
label to hypothalamus;
Alternative 1:
a. fMRI;
b. scan detects changes in blood flow/oxygen in blood
OR
more active parts of brain receive more blood flow;
Alternative 2:
c. lesions/autopsy;
d. part of the brain damaged
OR
loss of function detected;
Alternative 3:
e. stimulation during open brain surgery;
f. reaction observed;
The “f” must be written for fMRI.
Description must relate to method named.