Brainscape's Knowledge GenomeTM

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


See full index

Y2 LCRS1 Endocrinology > Hyposecretion of Anterior Pituitary Hormones > Flashcards

Hyposecretion of Anterior Pituitary Hormones Flashcards

1
Q

What are three main types of panhypopituitarism?

A

Simmond’s Disease

Sheehan’s Syndrome

Pituitary Apoplexy

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

What is the difference between primary, secondary and tertiary endocrine gland disease?

A

Primary – problem with the endocrine gland/hormone released

Secondary – problem with the pituitary gland/hormone released

Tertiary – problem with the hypothalamus

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

What is the term given to decreased secretion of all anterior pituitary hormones?

A

Panhypopituitarism

Can be congenital or acquired

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

What are the features of congenital panhypopituitarism?

A
  • Rare
  • CAUSE: Usually due to mutations of transcription factor genes needed for normal anterior pituitary development eg PROP1 mutation
  • Deficient in GH and at least 1 more anterior pituitary hormone

Presentation:

  1. Short stature
  2. Hypoplastic anterior pituitary gland on MRI
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

List some different types of acquired panhypopituitarism.

A
  • Tumours- hypothalamic-craniopharyngioma; pituitary–adenomas, metastases, cysts.
  • Radiation- hypothalamic/pituitary damage, GH most vulnerable, TSH relatively resistant
  • Infection eg meningitis
  • Traumatic brain injury
  • Infiltrative disease – often involves pituitary stalk eg neurosarcoidosis
  • Inflammatory (hypophysitis) - pituitary is recognised as non-self
  • Pituitary apoplexy - haemorrhage (or less commonly infarction)
  • Peri-partum infarction (Sheehan’s syndrome)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the presentation of Simmond’s disease (panhypopituitarism) .

A

Symptoms due to deficient hormones:

FSH/LH:

  • Secondary hypogonadism
  • Reduced libido
  • Secondary amenorrhoea
  • Erectile dysfunction

ACTH:

  • Secondary hypoadrenalism (cortisol deficiency)
  • Fatigue

TSH:

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

State the cause of Sheehan’s syndrome and describe its onset.

A

This is specific to WOMEN

Anterior pituitary enlarges during pregnancy (lactotroph hyperplasia)

Sheehan’s = vasoconstrictor spasm of hypophysial arteries as a result of post-partum haemorrhage (hypotension after haemorrhage) –> large pituitary no longer gets enough blood supply so cannot function proper –> spasm causes pituitary infarction

This develops very RAPIDLY

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

Why does the anterior pituitary enlarge during pregnancy?

A

Lactotroph hyperplasia

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

How does Sheehan’s syndrome present?

A
  • Lethargy, anorexia, weight loss – TSH/ACTH/(GH) deficiency
  • Failure of lactation – PRL deficiency
  • Failure to resume menses post-delivery

Posterior pituitary usually not affected

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

What is pituitary apoplexy? Describe its onset and which patients it most affects.

A

This is similar to Sheehan’s syndrome but isn’t specific to women

It is caused by intra-pituitary infarction or haemorrhage

This also has a RAPID presentation in patients with:

  • pre-existing pituitary tumours
  • or may be the first presentation of a pituitary adenoma.
  • or can be precipitated by anticoagulants.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the onset/presentation of pituitary apoplexy.

A

SEVERE sudden onset headache - “apopletic rage”

Visual field defect – compressed optic chiasm, bitemporal hemianopia

Cavernous sinus involvement may lead to diplopia(double vision) (CNIV, VI), ptosis (drooping of upper eyelid)(CNIII)

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

Why is a single measurement of most hypothalamic hormones not useful?

A

Most hypothalamic hormones tend to be released in pulses

FSH/LH is cyclical

GH/ACTH is pulsatile

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

What type of test do you do to test if someone is producing a hormone?

A

Stimulation/provocation test

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

How are the releasing hormones administered in stimulated pituitary function tests?

A

Intravenous

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

Describe how the stimulates pituitary function tests are done.

A
  • ACTH and GH are “stress” hormones = hypoglycaemia <2.2mM = stress so you give insulin to stimulates GH and ACTH(measure cortisol)
  • To stimulate TSH give TRH
  • To stimulate FSH&LH give GnRH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

For each of the following anterior pituitary hormone deficiencies, state the replacement used and the parameter that is monitored during treatment:

  • a. ACTH
  • b. TSH
  • c. Women - LH/FSH
  • d. Men - LH/FSH
  • e. GH
A

a. ACTH - Give hydrocortisone - Monitor serum cortisol
b. TSH - Give thyroxine - Monitor serum T4
c. Women – LH/FSH - Give ethinyloestradiol and medroxyprogesterone - Monitor libido and oestrogen deficiency
d. Men – LH/FSH - Give testosterone undecanoate - Monitor libido and serum testosterone
e. GH - Give GH - Monitor IGF I

17
Q

What are the effects of a lack of somatotrophin in children and in adults?

A

Children – stunted growth (pituitary dwarfism) - 2SD<mean></mean>

<p>Adults – loss of GH effects are uncertain</p>

</mean>

18
Q

State some other causes of short stature.

A

Genetic

Malnutrition

Emotional deprivation

Endocrine disorders

Skeletal dysplasias

Systemic disease

Malabsorption e.g. coeliac disease

Malnutrition

19
Q

List some genetic diseases, systemic diseases and skeletal dysplasias which can cause short stature.

A

Genetic - Down’s syndrome, Turner’s syndrome, Prader Willi syndrome

Systemic disease - Cystic Fibrosis, Rheumatoid arthritis

Skeletal dysplasias - Achondroplasia, osteogenesis imperfecta

20
Q

What are most common endocrine-related causes of short statue?

A
  • Decreased production of GHRH/deficiency
  • Cushing’s syndrome
  • Hypothyroidism
  • Poorly controlled T1DM
21
Q

As well as being its own hormone, GH stimulates the production of other hormones. State one important hormone that is stimulated by GH, its side of production and its effects.

A

IGF I = insulin-like growth factor I It is produced in the LIVER

It mediates growth effects

22
Q

List three causes of short stature in children and state where they affect the growth axis.

A
  1. Pituitary dwrafism - lack of GH in childhood
  2. Laron dwarfism - GH receptor defect
  3. Praeder Willi syndrome - GH deficiency secondary to hypothalamic dysfunction
23
Q

What is achondroplasia? Is it an endocrine disorder?

A
  • Achondroplasia = mutation in FIBROBLAST GROWTH FACTOR RECEPTOR 3 (FGF3)
  • Abnormality in growth plate chondrocytes - impaired linear growth
  • Average size trunk
  • Short arms and legs
24
Q

What type of dwarfism is caused by a GH receptor defect?

A

Laron Dwarfism

25
Q

Describe the IGF I levels in people with Laron dwarfism. What is the treatment?

A

LOW IGF I

Because functioning GH receptors are necessary for GH to stimulate the production of IGF I

IGF-I treatment in children can increase height

26
Q

How do you diagnose short stature in children?

A

Use mid-parental height -predicted adult height based on father’s and mother’s height.

Height is monitored on centile charts and recorded - if the child falls off the centile chart at any point this may be due to a hormone deficiency

27
Q

What are the causes of acquired GH deficiency in adults?

A
  • TRAUMA
  • PITUITARY TUMOUR
  • PITUITARY SURGERY
  • CRANIAL RADIOTHERAPY
28
Q

What is the gold standard method of testing the ability of the pituitary to release growth hormone?

A

PROVACATION CHALLENGE = Insulin-induced hypoglycaemia

Hypoglycaemia is a potent stimulus for growth hormone release

29
Q

State three other triggers (other than insulin induced hypoglycaemia) for an increase in GH release.

A
  1. GHRH + Arginine (more effective in combination)
  2. Glucagon (seems odd as this increases blood glucose but it turns out that in people who have GH deficiency, glucagon is good at stimulating growth hormone release)
  3. Exercise

Measure plasma GH at specific time points before and after.

30
Q

Describe how the insulin-induced hypoglycaemia test is used to test GH secretion.

A

In a normal subject, the insulin-induced hypoglycaemia will give a massive rise in GH secretion

If you have a partial deficiency of GH then your response will be reduced

31
Q

How is the human recombinant GH in GH therapy administered, how often and how is it monitored?

A
  • Daily, subcutaneous injection

Monitor clinical response & adjust dose to IGF-1

NB: approved naem = SOMATOTROPIN

32
Q

State some signs and symptoms of GH deficiency in adults.

A
  • Decreased muscle mass
  • Increased adiposity
  • Increased waist: hip ratio
  • Decreased plasma HDL and increased LDL
  • Reduced muscle strength and bulk –> reduced exercise performance
  • Impaired psychological wellbeing and quality of life
33
Q

What are the potential benefits of GH therapy in adults?

A
  • Improved body composition
  • Improved muscle strength and exercise capacity
  • Normalisation of HDL-LDL
  • Increased bone mineral content
  • Improved psychological and mental wellbeing and quality of life
34
Q

What are the potential risks of GH therapy in adults?

A

Increased susceptibility to cancer - but no data to support this currently

35
Q

State some of the effects of growth hormone therapy in children.

A
  • Increased linear growth
  • Decease in body fat
  • Younger children respond better
  • Obese children respond better
36
Q

In what order does loss of secretion occur?

A

Usually develops in adults with progressive loss of pituitary secretion

  • Gonadotrophins
  • GH
  • Thyrotrophin
  • Corticotrophin
  • Prolactin
37
Q

What is a problem with growth hormone therapy in children?

A

Tolerance may develop so you need to think about when to start GH therapy

Y2 LCRS1 Endocrinology (18 decks)

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