IMAT 2017 Q29 [Pituitary Function]

Which of the following could be a consequence of a reduction in pituitary function in an otherwise healthy human?

  1. more urine produced in a male or female
  2. infertility in a female
  3. infertility in a male

A. 1 and 2 only
B. 2 and 3 only
C. 2 only
D. 1, 2 and 3
E. 1 and 3 only

1 Like

The correct answer is D.

What is the pituitary gland ?

The pituitary gland, or hypophysis, is found at the base of the brain. It can be divided into 2 distinct structures, that have different embryological origins : anterior and posterior hypophysis.

Both lobes are made of different cells that ultimately secrete hormones, such as :

1. For the anterior lobe :

  • human growth hormone (hCG)
  • adrenocorticotropin (ACTH)
  • thyroid stimulating hormone (TSH)
  • gonadotropic hormones (LH & FSH) :
    • LH : stimulates the production of testosterone by Leydig cells in males and triggers ovulation in females

    • FSH : regulates puberty and more globally, the reproductive processes

  • prolactin

2. For the posterior lobe :

  • oxytocin
  • antidiuretic hormone (ADH, vasopressin) : it increases water resorption, making urine more concentrated.

With that being said, a reduction in pituitary function woul lead to infertility in both males and females due to less gonadotropins produced. Items 2 and 3 are correct.

Additionally, it would also lead to more urine produced due to the lack of water resorption as a consequence of the lack of vasopressin. Item 1 is correct.