AVP, oxytocin, growth hormones and pituitary Flashcards

1
Q

What is the pituitary gland?

A

Integrates signals and releases hormones that regulate the functions of other endocrine glands.
Vital roles in homeostasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the two lobes the pituitary gland split into?

A

Anterior and posterior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the driving force of the pituitary gland?

A

The hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Where is the pituitary gland located?

A

Base of the brain attached to the hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Anterior lobe of the pituitary gland

A

Synthesizes and secretes hormones in response to hypothalamic regulation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Posterior lobe of the pituitary gland

A

Stores and secrets hormones synthesized in the hypothalamus. (Does not produce any hormones)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Does the posterior pituitary produce hormones?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What two hormones are stored secreted by the posterior pituitary?

A
Antidiuretic hormones (ADH/vasopressin)
 Oxytocin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does antidiuretic hormone regulate (ADH/vasopressin)?

A

Regulation of renal failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does oxytocin regulate?

A

Regulation of uterine contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What the 4 things that feed into the hypothalamus that stimulate the posterior pituitary gland?

A
  1. Hyperosmolarioty (main)
  2. Angiotensin II (main)
  3. Decreased atrial receptor firing
  4. Sympathritric stimulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What two reports does ADH/vasopressin work on?

A

V1 and V2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does activation of the V1 receptor do?

A

Acts on the blood vessels casing constriction, increased systemic vascular resistance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does activation of the V2 receptor do?

A

Kidneys, fluid reabsorption, increased blood volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the overall affect of vasopressin/ADH after activation V1 and V2?

A

Increased arterial pressure (increased BP). V2 regulates water excretion by decreasing, so retaining water.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Effect of reduced ADH/vasopressin

A

Diabetes insipidus, copious hypotonic urine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Treatment for reduced ADH/vasopressin

A

V2 agonist - desmopressin (mimics vasopressin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Effect of excess ADH/vasopressin

A

Hyponatremia (diluted NA due to excess water)

Oedema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Treatment for excess ADH/vasopressin

A

Demeclocycline (blocks transduction of V2)
Tolvaptan (V2 antagonist) (expensive)
Restrict fluids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Cause of excess ADH/vasopressin

A

Tumor, head injury, TB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

ADH/vasopressin mechanism (5)

A
  1. Hypothamalus stimulates posterior pituitary through hyperosmolarity and angiotensin, II
  2. Vapsoresisibe secreted and acts of V1 and V2 receptor.
  3. V1= blood vessel constriction = increased systemic vascular resistance
  4. V2= Kidney fluid reapportion = increased blood volume (water retention)
  5. Increased arterial pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Oxytocin mechanism (3)

A
  1. Stretch of uterus, uterine cervix and stimulation of breasts increases action potentials in axons of oxytocin-secreting neuron.
  2. Action potential go to hypothalamus and simulation secretion of oxytocin via posterior pituitary
  3. Oxytocin release increased uterine contraction and milk release from breasts.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Clinical use of oxytocin (3)

A

Labour induction (Slow IV)
Prevention/treatment of hemorrhage (Prophylactic IM)
Labour too quick (Antagonist: Atosiban)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Two types of hormones produced and secrete by anterior pituitary

A

Tropic and directly acting

25
Q

What do tropic pituitary hormones do?

A

Affect the section of other endocrine glands

26
Q

What do directly pituitary hormones do?

A

Act directly on pituitary glands

27
Q

Tropic pituitary hormones (3)

A
  • Adrenocorticoid hormones (corticotrophin)
  • Follicle-stimulating hormone (FSH) and luteinising hormone (LH)
  • Thyrotropin (Thyroid stimulating hormone
28
Q

Directly pituitary hormones (2)

A
Growth hormone (somatropin)
 Prolactin
29
Q

Adrenocorticotropic hormone

(corticotropin) target

A

Adrenal glands

30
Q
Follicle-stimulating hormone (FSH) and 
 luteinising hormone (LH) target
A

Reproductive system

31
Q

Thyrotropin (thyroid-stimulating

hormone) target

A

Thyroid gland

32
Q

Growth hormone (somatotropin) target

A

Liver, bone, muscles

33
Q

Prolactin target

A

Mammary glands

34
Q

Adrenocorticotropic hormone

(corticotropin) effect

A

Stimulate production of glucocorticoids, which regulate metabolism and stress response

35
Q
Follicle-stimulating hormone (FSH) and 
 luteinising hormone (LH) effect
A

FSH stimulates maturation/production of sex cells LH stimulates sex hormones by the gonads

36
Q

Thyrotropin (thyroid-stimulating

hormone) effect

A

Stimulates the release of thyroid hormones which regulate metabolism

37
Q

Growth hormone (somatotropin) effect

A

Induce production of insulin-like growth factors, which stimulate body growth and higher metabolic rate

38
Q

Prolactin effect

A

Promotes milk production

39
Q

Adrenocorticotropic hormone

(corticotropin) RH/IH

A

Corticotropin-RH

40
Q
Follicle-stimulating hormone (FSH) and 
 luteinising hormone (LH) RH/IH
A

Gonadotropic RH

41
Q

Thyrotropin (thyroid-stimulating

hormone) RH/IH

A

Thyrotropin-RH

42
Q

Growth hormone (somatotropin) RH/IH

A

Growth hormone-RH and Growth

hormone-IH (somatostatin)

43
Q

Prolactin RH/IH

A

Prolactin-RH and prolactin-IH

(dopamine)

44
Q

What are hypothalamic releasing factors?

A

Peptides
Some regulate more than one hormone, and some hormones regulated by more than one releasing factor
They also can on neurotransmitters in the CNS.

45
Q

Anterior pituitary hormone regulation mechanism general

A
  1. Hypothalamus detects need for inhibition or increase of hormones and relapses RH/IH.
  2. IH turns pituitary off
  3. RH stimulates pituitary release of hormone to act on tissue which has an effect.
  4. After desired effect, feedback to hypothalamus and pituitary to stop.
46
Q

When are high levels of growth hormone released? (4)

A
  • Exercise
  • Sleep
  • Stress
  • Thyroid hormone enhanced secretion
47
Q

What is the growth hormone sensitive to?

A

Very sensitive to noradrenergic activation, beta-antagonist promotes secretion and alpha antagonist inhibit secretion.

48
Q

Two types of growth hormone deficiency

A

Secretion deficiency

Receptor defects

49
Q

Growth hormone secretion deficiency effects

A

Hypothalamic or pituitary dysfunction e.g. turners syndrome

50
Q

Growth hormone receptor defects effects

A

Laron type dwarfism; fail to produce IGF in response to GH

51
Q

Clinical manifestation of growth deficiency dependent on age

A

Children: growth retardation/dwarfism

Adult: increased body fat, decreased muscle and bone mass

52
Q

Treatment for dwarfism due to growth hormone section deficiency

A

Somatropin – SC injection strict guidelines for use and specialist initiation.

53
Q

What neurotransmitter can reduce growth hormone secretion?

A

Dopamine

54
Q

Growth hormone and glucose

A

Counter-regulates glucose:
Hyperglycemia action
Causes insulin resistance

55
Q

What neurotransmitter can reduce prolactin release?

A

Dopamine

56
Q

Hyperprolactinemia

A

Too much prolactin

57
Q

Treatment for hyperprolactinemia: Bromocriptine

A

Dopamine agonist

Reduces prolactin secretion

58
Q

Treatment for hyperprolactinemia: Cabergoline

A

Alternative dopamine agonist
Less side effects
Less data in pregnancy

59
Q

Treatment for hyperprolactinemia: Quinagolide

A

Non-ergot alkaloid