Identify the parts of the brain indicated on the diagram below.

Outline the unconscious control of the heart rate.

Describe different aspects of the processing of visual stimuli.

I. cerebral hemisphere / cerebrum;
II. hypothalamus;
III. cerebellum;
IV. medulla oblongata;
Award [1] for any two of the above.

heart can contract without nervous stimulation/myogenic contractions;
SA node is pacemaker/generates heart beat/initiates each cardiac cycle;
epinephrine/adrenalin speeds up the heart rate;
autonomic/sympathetic and parasympathetic nervous system control;
sympathetic speeds up heart rate;
parasympathetic/vagus nerve slows heart rate (back to normal/resting rate);

edge enhancement is greater perception at edges of light/dark areas;
caused by processing in two types of ganglion cell in retina;

contralateral is processing left field of view in right side of brain / vice versa;
cross over between left and right sides in the optic chiasma;

convergence is combining impulses from groups of (rod/cone) cells;
done by bipolar cells in retina;

Part (a) was straightforward for well prepared candidates.

In part (b) candidates were expected to base their answer on assessment statement E5.4 and outline the roles of the sympathetic and parasympathetic nervous systems. Some candidates failed to distinguish between the control of the heart rate by these parts of the autonomic nervous system and the stimulation of the heart beat by the sino-atrial node.

Part (c) was answered in great detail by the best prepared candidates, who described edge enhancement, contralateral processing and convergence. There was some misunderstanding of contralateral processing, with candidates suggesting that all stimuli perceived by an eye are processed by the opposite side of the brain, rather than each side of the brain processing stimuli from the same half of the visual field in both eyes.