CSGD Quiz 4 2007

1

Which ONE of the following statements regarding the pituitary gland is NOT CORRECT?


  It synthesizes antidiuretic hormone (ADH).

  It has a portal venous system coming from the hypothalamus.

  It is derived in part from ectoderm.

  It is closely related to the hypothalamus.

  It secretes thyroid stimulating hormone (TSH).


A is incorrect: ADH is released by the posterior pituitary, but produced by the hypothalamus. B is correct: The portal system links the hypothalamus and the anterior pituitary. C is correct: The posterior pituitary arises from the ectoderm. D is correct. E is correct: TSH is secreted by the anterior pituitary.

2

Under which ONE of the following circumstances are growth hormone levels in the blood NOT increased?


  Hypothalamic growth hormone releasing hormone is released.

  Hypothalamic somatostatin is released.

  The subject undertakes strenuous exercise.

  Following an injection of insulin.

  The subject goes to sleep.


A is incorrect: GHRH is the main tropic hormone for GH. B is correct: Somatostatin decreases GH secretion. C is incorrect: Exercise will stimulate GH secretion. D is incorrect: GH levels usually rise in response to insulin. E is incorrect: Most GH secretion happens at night.

3

Which ONE of the following statements regarding diabetes insipidus is NOT CORRECT?


  The urine is dilute.

  Plasma osmolality is increased.

  Total body water is decreased.

  The urine becomes more concentrated after vasopressin administration.

  The plasma level of anti-diuretic hormone (ADH) is increased.


A is correct: Diabetes insipidus results in fast clearance of urine and it is therefore unconcentrated. B is correct: Loss of body water will increase plasma osmolarity. C is correct. D is correct: ADH will cause slower clearance and better concentration of urine. E is incorrect: Reduced/absent ADH is a cause of diabetes insipidus.

4

Which ONE of the following statements about breast development is NOT CORRECT?


  Estrogen from the ovary and placenta stimulates mammary breast duct development during pregnancy.

  In the non-pregnant state mammary alveoli are non-secretory.

  During pregnancy mammary glandular development during pregnancy is stimulated by progesterone which is produced by the placenta but not the ovaries.

  Prolactin concentrations increase during pregnancy.

  During puberty, prolactin and estrogen stimulate development of the breast ducts.


C is incorrect because during pregnancy progesterone is produced by both the ovary and placenta and stimulates mammary breast glandular tissue/alveoli (not duct) development.

5

Which ONE of the following statements regarding surgical excision of a lump within the thyroid gland is NOT CORRECT?


  It may result in one or more of the parathyroid glands being inadvertently removed.

  It may affect abduction of one or both vocal cords.

  It may paralyse the posterior cricoarytenoid muscle.

  It puts the recurrent laryngeal nerves at risk of injury.

  It is unlikely to produce much bleeding because of the poor blood supply to the thyroid gland.


The thyroid is the most vascular gland in the body.

6

Which ONE of the following statements regarding hypothyroidism is NOT CORRECT?


  It predisposes to hyperlipidaemia.

  It is associated with decreased sensitivity to cold.

  In infants it causes mental retardation.

  It may be acquired congenitally.

  It is a cause of short stature in infants.

7

When measuring the level of a particular hormone in the blood using an immunoassay, all of the following are usually required EXCEPT:


  Known amounts of the hormone to be measured to set up a “standard curve”.

  Minute amounts of a purified form of the hormone appropriately “labelled” with a radio-isotope or other label.

  Antibody to that hormone.

  A detection method to measure the total amount of “label”.

  A blood sample with an unknown amount of the hormone to be measured.


It is not the total amount of label which is important and measured, but the amount of bound label. The amount of bound hormone to the antibody is influenced by the amount of unlabelled hormone also used in the assay. Using known amounts of unlabelled hormone allows a standard curve to be established using the "bound label" measured, and the amount of hormone in the unknown sample can then be calculated from its own "bound label" measurement.

8

Which ONE of the following statements about a phaeochromocytoma is NOT CORRECT?


  It arises from cells of the adrenal cortex.

  It induces glycosuria.

  It induces hypertension.

  It is an encapsulated tumour.

  It has a high content of catecholamines.


Phaeochromocytomas arise from the adrenal medulla and result in the overproduction of catecholamines. They often present paroxysmally with episodes of:

  • Severe headaches
  • Palpitations
  • Flushing
  • Abdominal pain
  • High blood pressure
  • Elevated BG levels due primarily to catecholamine-induced lipolysis, and also due to direct stimulation of gluconeogenesis

9

Which ONE of the following is NOT a site of testosterone production?


  The ovary.

  The fetal testis.

  The adrenal medulla.

  The ageing testis.

  The neonate.


The adrenal medulla synthesises catecholamines.

10

Oestrogen has a complex synthetic pathway. Which of the following is/are oestrogen precursors?


  Testosterone.

  DHEA.

  Cholesterol.

  Progesterone.

  All of the above.


Note that DHEA can be testosterone precursor.