Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Year 2 BRS > Endocrinology - Hypopituitarism > Flashcards

Endocrinology - Hypopituitarism Flashcards

1
Q

Name the hormones produced by the pituitary gland (6)

A

Growth hormone (somatotrophin)
Prolactin
TSH
LH, FSH
ACTH (corticotrophin)

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

Name the circulation in the anterior pituitary, and its constituent parts

A

Hypophyseal portal circulation
Primary capillary plexus (located in he median eminence)
Hypophyseal portal veins
Secondary capillary plexus

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

Briefly explain the hypothalamo-pituitary portal

A

Hypothalamic releasing or inhibitory factors (named after the fact they are released in the hypothalamus) travel via the portal circulation to the anterior pituitary to regulate hormone production of the ANTERIOR pituitary

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

What are the functions of the anterior pituitary hormones?(5)

A

GH - growth of soft tissue (and bones before fusion of the epiphyseal plate)
Prolactin - milk production
FSH and LH - production of sex hormones
TSH - stimulation of thyroid hormones
ACTH - stimulation of cortisol release

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

Most common PRESENTING forms of anterior pituitary failure? (3)

A

Thyroid hormones
Adrenal cortex (cortisol)
Gonad failure

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

Explain the difference between primary and secondary failure of glands? (Thyroid, adrenals, gonads)

A

Primary disease is failure of the gland itself (I.e. autoimmune damage, trauma etc….)

Secondary disease is failure of signals due to hypothalamic or pituitary damage

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

What is the most common form of hypothyroidism?

A

Primary hypothyroidism, particularly due to autoimmune destruction

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

What is primary vs secondary hypothyroidism?

A

Primary due to destruction of the gland (usually autoimmune damage)
Secondary due to pituitary tumour damaging thyrotrophs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is primary vs secondary hypothyroidism?

A

Primary due to destruction of the gland (usually autoimmune damage)
Secondary due to pituitary tumour damaging thyrotrophs

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

What are the differences in hormone levels between primary and secondary hypothyroidism?

A

Primary sees T3 and T4 falling, and TSH increasing
Secondary sees T3, T4 and TSH falling

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

Explain the difference in TSH levels in primary and secondary hypothyroidism?

A

In primary, TSH increases as the negative feedback system is still intact, so the lack of T3/T4 stimulates TSH release in pituitary.

In secondary, the pituitary is damaged and so the negative feedback system is nonfunctional, as TSH is unable to be produced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Primary vs secondary hypoadrenalism?

A

Primary features the destruction of the adrenal cortex itself.

Secondary features a pituitary tumour that damages corticotrophs

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

What are the differences in hormones between primary and secondary hypoadrenalism?

A

Primary has low cortisol and high ACTH

Secondary has low cortisol and low ACTH

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

Explain the differences in ACTH levels between primary and secondary hypoadrenalism

A

Primary has high ACTH, as adrenal cortex is damages not pituitary, so negative feedback loop is intact, leading to increased ACTH production due to lack of cortisol as corticotrophs are undamaged

Secondary has low ACTH as corticotrophs are damaged, so no ACTH production and a non functional negative feedback loop

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

Primary vs secondary hypogonadism

A

Primary is destruction of testes or ovaries, leading to low testosterone or oestrogen, but high LH and FSH

Secondary is pituitary damage affecting gonadotrophs, so LH/FSH can’t be made. LH and FSH fall. Testosterone/oestrogen also fall

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

What is the most common cause of hypopituitarism? (Congenital vs acquired)

A

Acquired much more common

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

How does congenital hypopituitarism arise?

A

Usually due to mutations of transcription factor genes needed for normal anterior pituitary development

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

How does congenital hypopituitarism present? (3)

A

Deficient in GH and at least 1 other anterior pituitary hormone
Short stature
Hypoplastic anterior pituitary gland (visible on an MRI)

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

What are the causes of acquired hypopituitarism? (8)

A

-Tumours (e.g. adenomas, metastases, cycsts)
-Radiation (damage to either pituitary or hypothalamus)
-Infection (e.g. meningitis)
-Trauma
-Pituitary surgery
-Inflammation (hypophysitis)
-Pituitary apoplexy (haemorrhage)
-Sheehan’s syndrome (peri-partum infarction)

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

What does hypopituitarism affect?

A

Can affect one axis, several or all
Often describes anterior pituitary but some forms can cause posterior pituitary damage as well

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

What is panhypopituitarism?

A

Total loss of anterior and posterior pituitary function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the term for total loss of all pituitary function?

A

Panhypopituitarism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Which pituitary hormones ade most sensitive to radiation?

A

GH and gonadotrophins (LH/FSH)

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

What are the associated risks with the pituitary gland, re radiotherapy?

A

GH and gonadotrophins affected
Risk of damage persists for up to 10 years, so annual assessments needed

25
Q

How does hypopituitarism affecting LH/FSH production present? (4)

A

Reduced libido
(Secondary) amenorrhoea
Erectile dysfunction
Reduced pubic hair

26
Q

How does hypopituitarism affecting ACTH production present?

A

Fatigue

27
Q

How does hypopituitarism affecting TSH production present?

A

Fatigue

28
Q

How does hypopituitarism affecting prolactin production present?

A

Inability to breastfeed

29
Q

How does hypopituitarism affecting growth hormone production present?

A

Reduced quality of life (decreased muscle mass and endurance, decreased bone density, wide range of other symptoms attributing to a lower quality of life)
Short stature only in children

30
Q

Why does low growth hormone production only cause short stature with congenital hypopituitarism or hypopituitarism acquired during childhood?

A

Growth hormone only used for growth and height in children, before epiphyseal plates have fused. Adults have already finished growing

31
Q

Why do cases of hypopituitarism causing prolactin deficiency often go unnoticed?

A

Asymptomatic in all members of the population apart from mothers attempting to breastfeed, due to prolactin having limited significant role in other body processes

32
Q

What is Sheehan’s syndrome?

A

Post-partum pituitary infarction due to post-partum haemorrhage (PPH) and subsequent hypotension

33
Q

How does Sheehan’s syndrome present? (5)

A

Lethargy, anorexia, weight loss - TSH/ACTH/GH deficiencies
Failure to lactate - prolactin deficiency
Failure to resume menses post delivery - gonadotrophin deficiency
Posterior pituitary usually unaffected

34
Q

What other diagnoses can be considered in a patient presenting with Sheehan’s syndrome-like symptoms?(4)

A

Primary thyroiditis (autoimmune destruction)
Post-partum depression
Anaemia
Pituitary apoplexy

35
Q

Why is primary thyroiditis quite common post-partum?

A

Reactivation of immune system post-partum can lead to autoimmune conditions
Immune system is “jump-started”

36
Q

How might pituitary apoplexy occur?

A

Pituitary gland vulnerable to haemorrhaging from gestational hypertension
Normal physiology of pregnancy has lactotroph hyperplasia, more susceptible to haemorrhages

37
Q

What symptoms might pituitary apoplexy present with that could immediately distinguish it from Sheehan’s syndrome, and why they occur?

A

Visual field defects such as bitemporal hemianopia, due to compressed optic chiasm
Diplopia(IV, VI) or ptosis(III) due to cavernous sinus involvement

38
Q

How might pituitary apoplexy present? (4)

A

Severe sudden onset headache
Visual field defect
Ptosis(III)
Diplopia(IV, VI)

39
Q

What are some causes of pituitary apoplexy? (3)

A

Haemorrhage into pituitary gland, often in patients with pre-existing adenomas
May be the first presentation of an adenoma
Can be precipitated by anti-coagulants

40
Q

What are the problems with measuring the basal plasma concentrations of hormones as a means of diagnosing hypopituitarism? (4)

A

Cortisol - can only be measured in the morning
T4 - very long circulating time
FSH/LH - cyclical in women
GH/ACTH - pulsatile

41
Q

What investigation is used to diagnose hypopituitarism?

A

Dynamic pituitary function test

42
Q

Describe the investigation for hypopituitarism (5)

A

An injection of insulin is given to induce hypoglycaemia (<2.2mM) = “stress”
At the same time, TRH and GnRH is injected
Insulin induced hypoglycaemia stimulates GH release and ACTH release (cortisol is measured)
TRH stimulates TSH release
GnRH stimulates FSH/LH release

43
Q

Which groups of patients are unable to take the dynamic pituitary function test?(3)

A

Elderly people, people with epilepsy, people with heart conditions

44
Q

What imaging is used for investigations of the pituitary gland?

A

MRI (magnetic resonance imaging)

45
Q

What is the only hormone that cannot be replaced in hypopituitarism?

A

Prolactin

46
Q

Outline the steps for treating GH deficiency (3)

A

Confirm GH deficiency on dynamic pituitary function test (specifically with insulin-induced hypoglycaemia)
Assess quality of life using specific QoL questionnaire
Daily injection

47
Q

Why can GH deficiency not be treated orally?

A

The treatment consists of peptide hormones which would be broken down in the stomach

48
Q

Outline the steps for treating TSH deficiency (3)

A

Replace with once daily levothyroxine
TSH will be low as negative feedback system is non-functional, so TSH levels cannot be used to adhust dose such as in primary hypothyroidism
Aim for a T4 range above the middle of the reference range

49
Q

Outline the steps for treating ACTH deficiency (2+2)

A

Replace cortisol instead of ACTH
Give synthetic glucocorticoids
Options:
Prednisolone once daily (e.g. 3mg)
Hydrocortisone 3x daily (e.g. 10/5/5mg)

50
Q

Which patients are more at risk of an “adrenal crisis”?

A

Patients with primary adrenal failure (Addison’s) or secondary adrenal failure (ACTH deficiency)

51
Q

What do adrenal crises commonly feature? (4)

A

Dizziness, hypotension, vomiting, weakness
Can result in collapse and death

52
Q

What are the “sick day rules” for patients at risk of adrenal crises?(3)

A

Steroid alert pendant/bracelet
Double glucocorticoid does if fecer/intercurrent illness
If unable to take tablets(e.g. vomiting, unconscious etc…), inject intramuscularly (IM) and straight to A&E

53
Q

How is FSH/LH deficiency treated in men where fertility is NOT required?(3)

A

Replace testosterone
Topical or IM most popular methods
Measure plasma testosterone

54
Q

Why does replacing testosterone not result in fertility in men?

A

Replacing testosterone does not result in spermatogenesis, this requires LSH and FH

55
Q

How is FSH/LH deficiency treated in men where fertility is REQUIRED?(4)

A

Induction of spermatogenesis by gonadotropin injections
Best response if secondary hypogonadism has developed after puberty
Measure testosterone, semen analysis
Sperm production may take 6-12 months

56
Q

How is FSH/LH deficiency treated in women where fertility is NOT required?(3)

A

Replace oestrogen
Oral or topical
Needs additional progesterone to prevent endometrial hyperplasia

57
Q

How is fertility induced in women with FSH/LH deficiency?

A

Carefully timed gonadotropin injections IVF

58
Q

Why is progesterone given to women with FSH/LH deficiency even when fertility is NOT required?(2)

A

To induce shedding of uteral lining
Uteral lining should be shed 3-4 times per year minimum so as to prevent endometrial hyperplasia, which can lead to endometrial cancer

Year 2 BRS (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions