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Flashcards in Pituitary Deck (68)
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1
Q

What are the 6 hormones secreted by the anterior lobe of the pituitary?

A
1 - ACTH (Adrenocorticotropic)
2 - TSH (Thyroid stimulating)
3 - GH (Growth)
4 - FSH
5 - LH
6 - Prolactin
2
Q

What are the 2 hormones secreted by the posterior lobe of the pituitary?

A

1 - Vasopressin (ADH)

2 - Oxytocin

3
Q

What 2 factors regulate hypothalamus function?

A

1 - Hormone mediated signals, e.g. negative feedback.

2 - Neural inputs.

4
Q

Which 3 nuclei of the hypothalamus have the greatest influence on the regulation of endocrine functions?

A

1 - Paraventricular

2 - Supraoptic

3 - Ventromedial

5
Q

What is the name of the bone in which the pituitary sits?

A

The sphenoid bone.

6
Q

How does the hypothalamus convey hormones to the anterior pituitary? What about the posterior pituitary?

A

Anterior - Through the hypothalamic - hypophyseal portal system.

Posterior - Through neurosecretory axons extending the length of the stalk.

7
Q

Which hormones stimulate and inhibit the release of growth hormone from the anterior pituitary?

A

Growth hormone releasing hormone (GHRH, from hypothalamus) - stimulates.

Somatostatin (from kidney delta cells) - Inhibits.

8
Q

Which hormone stimulates the release of FSH and LH from the anterior pituitary?

A

Gonadotropin Releasing Hormone (GnRH).

9
Q

Which hormone stimulates the release of adrenocorticotropic hormone from the anterior pituitary?

A

Corticotropin releasing hormone (CRH).

10
Q

Which hormone stimulates the release of thyroid stimulating hormone from the anterior pituitary?

A

Thyrotropin releasing hormone (TRH).

11
Q

Which hormone inhibits the release of prolactin from the anterior pituitary?

A

Dopamine.

12
Q

What is the function of ACTH?

A

Regulates cortisol (glucocorticoid) release from the glomerulosa fasciculata.

13
Q

What is the function of prolactin?

A
  • Stimulates the mammary gland to produce milk.

- Suppresses the release of gonadotropin releasing hormone.

14
Q

What is the function of oxytocin?

A
  • Contraction of the womb during childbirth.

- Plays a role in lactation.

15
Q

What is the function of vasopressin / ADH? How does it carry out its function?

A
  • Increases water reabsorption at the collecting duct of the kidney.
  • Acts on V2 receptors in the kidney.
  • Causes aquaporins to fuse with the luminal membrane.
16
Q

What term can be used to describe the nature of release of growth hormone?

A

Pulsatile.

17
Q

What 3 factors stimulates growth hormone release? What suppresses it?

A

1 - Hypoglycaemia.

2 - Exercise

3 - Sleep.

-Suppressed by hyperglycaemia.

18
Q

What molecule mediates the effects of growth hormone?

A

IGF-1

19
Q

Where is IGF-1 produced?

A

In the liver.

20
Q

What are the 5 main effects of growth hormone?

A

1 - Linear growth in children.

2 - Increases bone mass.

3 - Stimulates protein synthesis, lipolysis and glucose metabolism.

4 - Improved psychological well-being.

21
Q

What are the effects of FSH and LH?

A
  • FSH stimulates the ovarian follicle, causing an egg to grow.
  • Also triggers the production of estrogen in the follicle.
  • The rise in estrogen stimulates the pituitary gland to stop producing FSH and to start making more LH.
  • The shift to LH causes the egg to be released from the ovary, a process called ovulation.
22
Q

What is the function of TSH?

A

Stimulates the thyroid to release T3 and T4.

23
Q

What is the difference between T3 and T4?

A
  • T3 is active, T4 is inactive.

- Differ structurally by one iodine atom.

24
Q

In which nuclei of the hypothalamus is vasopressin / ADH synthesised?

A

In the suraoptic and paraventricular nuclei.

25
Q

How do secretory granules of ADH reach the posterior lobe?

A

Through axons of the supraoptichypophyseal tract.

26
Q

What are the major stimuli for secretion of vasopressin / ADH?

A
  • Hyperosmolarity.

- Circulating volume depletion.

27
Q

How is the release of oxytocin controlled?

A

By positive feedback.

28
Q

What is pituitary disease?

A

Hormone hypersecretion by an adenoma.

29
Q

What is an adenoma?

A

A benign tumor of glandular tissue.

30
Q

What are symptoms and complications of a pituitary adenoma?

A
  • Headaches
  • Hypothalamic damage
  • Damage to cranial nerves 2, 3, 4, 5, 6.
31
Q

List 5 causes of hypopituitarism.

A

1 - Pituitary tumours.

2 - Radiotherapy.

3 - Pituitary infarction.

4 - Trauma

5 - Hypothalamic releasing hormone deficiency (e.g. Kallmann syndrome).

32
Q

List 6 symptoms of growth hormone deficiency in adults.

A

1 - Decreased abdominal fat.

2 - Impaired lipid profile.

3 - Decreased muscle strength and exercise capacity.

4 - Impaired cardiac function.

5 - Decreased bone mineral density.

6 - Impaired psychological well-being.

33
Q

How is growth hormone deficiency diagnosed?

A

By GH stimulation tests:

  • Insulin tolerance test.
  • Glucagon
  • GHRH + Arginine
  • IGF-1
34
Q

What is a treatment for growth hormone deficiency?

A

Hormone replacement therapy.

35
Q

What are the symptoms of FSH/LH deficiency in children?

A

Delayed puberty.

36
Q

List 7 symptoms of FSH/LH deficiency in men.

A

1 - Decreased libido.

2 - Impotence.

3 - Decreased secondary sexual characteristics.

4 - Decreased muscle mass and strength.

5 - Osteoporosis.

6 - Anaemia.

7 - Decreased psychological well-being.

37
Q

List 6 symptoms of FSH/LH deficiency in women.

A

1 - Decreased libido.

2 - Menstrual disorders.

3 - Infertility.

4 - Dyspareunia (painful intercourse).

5 - Osteoporosis.

6 - Premature atherosclerosis.

38
Q

How is FSH / LH deficiency diagnosed?

A

In women:

By monitoring FSH, LSH and oestradiol (type of oestrogen).

In men:

By monitoring FSH, LH and morning testosterone.

39
Q

How is FSH / LH deficiency treated?

A

Hormone replacement therapy.

40
Q

List 7 symptoms of ACTH deficiency.

A

1 - Fatigue.

2 - Weakness.

3 - Nausea.

4 - Anorexia / weight loss.

5 - Hypoglycaemia.

6 - Hypotension.

7 - Anaemia.

41
Q

How is ACTH deficiency diagnosed?

A

By measuring 9am serum cortisol and ACTH.

Dynamic tests:

  • Short Syncathen tests.
  • Insulin tolerance tests.
  • Glucagon tests.
42
Q

How is ACTH deficiency treated?

A

With cortisol replacement.

43
Q

List 8 symptoms of TSH deficiency.

A

1 - Fatigue.

2 - Weakness.

3 - Cold intolerance.

4 - Bradycardia.

5 - Weight gain.

6 - Puffiness.

7 - Pale and dry skin.

8 - Constipation.

44
Q

How is TSH deficiency diagnosed?

A

By monitoring TSH, free T4 and free T3.

45
Q

How is TSH deficiency treated?

A

Hormone replacement therapy using levothyroxine.

46
Q

What is central diabetes insipidus?

A

Deficient secretion of vasopressin / ADH.

47
Q

List 7 causes of central diabetes insipidus.

A

1 - Autoimmune destruction of supraoptic and paraventricular nuclei.

2 - Genetic.

3 - Tumours.

4 - Neurosurgery.

5 - Trauma.

6 - Infections.

7 - Hypoxic encephalopathies (severe ischaemia).

48
Q

List 3 symptoms of ADH deficiency.

A

1 - Polyuria of dilute urine.

2 - Polydipsia (excessive thirst).

3 - Nocturia (need to wake up to urinate).

49
Q

List 5 causes of polyuria.

A

1 - Diabetes mellitus.

2 - Diabetes insipidus.

3 - Renal failure.

4 - Primary polydipsia.

5 - ADH deficiency.

50
Q

List 7 ways in which ADH deficiency can be diagnosed.

A
  • By monitoring urine output.
  • By measuring the osmolarity of the urine.
  • By measuring blood electrolytes (substances that give ions when dissolved in water).
  • By measuring blood glucose.
  • By measuring blood urea.
  • By measuring blood creatinine.
  • Water deprivation test.
51
Q

How is ADH deficiency treated?

A

Hormone replacement therapy using ADH analogues.

52
Q

What is acromegaly?

A

A disorder caused by a pituitary adenoma that results in hypersecretion of GH.

53
Q

List 8 symptoms of acromegaly.

A

1 - Enlargened bones of the face, feet and hands.

2 - Excessive hair growth in women.

3 - An enlargened jaw or tongue.

4 - A prominent brow.

5 - Excessive growth spurts.

6 - Weight gain.

7 - Swollen and painful joints.

8 - Left ventricular hypertrophy.

54
Q

List 3 ways in which acromegaly can be diagnosed.

A

1 - Oral glucose tolerance test.

2 - Monitoring IGF-1.

3 - Pituitary imaging.

55
Q

List 3 ways in which acromegaly can be treated.

A

1 - Surgically.

2 - Using drugs.

3 - Using radiotherapy.

56
Q

List 3 medical treatments for acromegaly.

A

1 - Dopamine agonists.

2 - Somatostatin analogues.

3 - GH receptor antagonists,

57
Q

List 2 symptoms of a prolactinoma.

A

1 - Hypogonadism.

2 - Galactorrhoea (excessive production of milk).

58
Q

List 2 ways in which a prolactinoma can be diagnosed.

A

1 - Exclde other causes of high prolactin.

2 - Pituitary imaging.

59
Q

What is a prolactinoma?

A

A tumour of the pituitary that results in excessive production of prolactin.

60
Q

List 3 ways in which a prolactinoma can be treated.

A

1 - Surgically.

2 - Using drugs.

3 - Using radiotherapy.

61
Q

What medical treatment is used to treat prolactinomas?

A

Dopamine agonists.

62
Q

What is Cushing’s syndrome?

A

Excessive cortisol released by the adrenal gland.

Two types:

1 - ACTH - Dependent:

-Abnormal secretion of ACTH or CRH.

2 - ACTH - Independent:

  • Iatrogenic (due to medical treatment) due to administration of steroids.
  • Adrenal diseases (adenomasor hyperplasia).
63
Q

List 8 symptoms of Cushing’s syndrome.

A

1 - Weight gain.

2 - Slow healing of cuts.

3 - Increased risk of infection.

4 - Fatigue.

5 - Weakness.

6 - Glucose intolerance.

7 - Decreased psychological well-being.

8 - Striae on the skin.

64
Q

List 5 ways in which Cushing’s syndrome is diagnosed.

A

1 - Monitor 24 hour urinary free cortisol.

2 - Monitor midnight serum or salivary cortisol.

3 - Dexamethazone suppression test (measures whether ACTH can be suppressed).
-Differentiates between ACTH dependent and ACTH independent.

4 - Measure 9 am ACTH.

5 - Imaging of the pituitary and adrenals.

65
Q

List 4 ways in which Cushing’s syndrome can be treated.

A

1 - Pituitary surgery.

2 - Radiotherapy.

3 - Drugs.

4 - Bilateral adrenalectomy (removal of both adrenal glands).

66
Q

List 3 drug treatments for Cushing’s syndrome.

A

1 - Metyrapone.

2 - Ketokonazole.

3 - Mitotane.

67
Q

Give an example of a symptom of a TSHoma.

A

Thyrotoxicosis (excess T3 / T4).

68
Q

List 4 symptoms of an FSHoma.

A

1 - Menstrual irregularities.

2 - Ovarian hyperstimulation.

3 - Testicular enlargement.

4 - Infertility.