List the hormones secreted by the pituitary gland. (30% marks) Outline the physiological factors that control secretion of hormones from the posterior pituitary. (70% marks)

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College Answer

Once again candidates are reminded to read and answer the question presented to them as
well as take into consideration the proportion of marks allocated. The expectation from the
first section of the question was for candidates to only “list” the hormones secreted by the
pituitary gland. The main hormones expected were ACTH, TSH, GH, FSH, LH and prolactin
anteriorly; and, ADH (vasopressin) and oxytocin posteriorly.
Unfortunately, a number of candidates confused which hormones come from which region
and therefore were unable to score marks in the second part. The question clearly asked for
factors controlling secretion of hormones from the posterior pituitary, therefore, detailed
descriptions of the mechanism of action of ADH in the kidney, or of hormones arising from
the anterior pituitary did not relate to the question and were not allocated marks.
With respect to ADH, most marks were gained by candidates who described not only
osmolality and plasma volume, but the relative sensitivity of the pituitary to these and the
pre-potent nature of volume over osmolality; also, the influence of other hormonal axes
involved in plasma volume regulation. Marks were also available for other inputs including
pain, stress, exercise, etc. A brief description of factors influencing oxytocin was also
expected.
Syllabus – N12d
Reference: Gannong p383, Guyton p359