List the hormones secreted by the pituitary gland. (30% marks)
Outline the physiological factors that control the secretion of hormones from the posterior pituitary. (70% marks)
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
List of pituitary hormones:
Control of vasopressin secretion:
Control of oxytocin secretion:
Leng, Gareth, Celine Caquineau, and Nancy Sabatier. "Regulation of oxytocin secretion." Vitamins & hormones 71 (2005): 27-58.
Holmes, Cheryl L., Donald W. Landry, and John T. Granton. "Science review: vasopressin and the cardiovascular system part 2–clinical physiology." Critical care 8.1 (2003): 15.
Lechan, Ronald M., and Roberto Toni. "Functional anatomy of the hypothalamus and pituitary." Endotext [Internet] (2016).
Musumeci, Giuseppe, et al. "A journey through the pituitary gland: Development, structure and function, with emphasis on embryo-foetal and later development." Acta histochemica 117.4-5 (2015): 355-366.
Amar, Arun Paul, and Martin H. Weiss. "Pituitary anatomy and physiology." Neurosurgery Clinics 14.1 (2003): 11-23.