Hormone

In the syllabus and the exam

Hormone questions are structured around a direct comparison with nerve impulses, and candidates are expected to contrast the two forms of coordination on three fronts: speed of response, duration of effect, and the pathway of transmission. Candidates should state that a hormone is a chemical messenger released directly into the blood by an endocrine gland, travels to a target organ often located some distance away, and produces an effect that develops more slowly but lasts longer than a nervous response, which instead depends on electrical impulses along specific neurons and produces a fast, short-lived, and more localised effect. Named hormones such as adrenaline, insulin and the reproductive hormones each carry their own specific gland, target organ and effect, and exam questions frequently ask candidates to identify all three correctly for a given hormone rather than describing hormones in general terms. A frequent structured-question format gives a physiological scenario, such as a sudden fright or a rise in blood glucose, and asks candidates to name the hormone released and describe its specific effect on the named target organ.

Example

Adrenaline is a hormone released into the blood that prepares the body for a fight-or-flight response during sudden danger.

Related terms

StimulusHomeostasisNeuron

Source:SRC-DSKP-EN