Brainscape's Knowledge GenomeTM

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


See full index

The Endocrine System > Pituitary Physiology > Flashcards

Pituitary Physiology Flashcards

1
Q

Which hormones can be produced by the anterior pituitary?

A
  1. ACTH
  2. TSH
  3. FSH
  4. LH
  5. PRL
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which hormones can be produced by the posterior pituitary?

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

Describe how thyroxine can be produced with hypothalmic stimulation

A
  1. Stress stimulus on hypothalamus
  2. Thyrotropin releasing hormone released
  3. Anterior pituitary releases thyrotropin
  4. Thyroid releases thyroxine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What releases corticotropin releasing hormone?

A

Hypothalamus

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

What effects does corticotropin releasing hormone have?

A

Acts on the pituitary to cause ACTH release

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

Where does ACTH act and what is the result of this?

A

Adrenal gland

Cortisol release

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

Why is prolactin different to other hormones in terms of its release?

A

Its release is under constant suppression by dopamine

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

If the pituitary hormone is GH, what is the peripherally acting hormone?

A

IGF-1

(insulin-like growth factor)

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

If hormone levels appear high, which type of test will be used?

A

Suppression test

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

Why is it a worry if a hormone suppression test fails?

A

It may suggest a tumour causing autonomous hormone release

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

If there is too little hormone, which test would be used?

A

Stimulation test

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

Which hormones are tested in an insulin stress test?

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

Describe an insulin stress test

A

Hypoglycaemia induced

Hormone (cortisol and GH) measured at 30 minute intervals for 2-3 hours

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

How can pituitary release of cortisol be tested?

A

Synacthen (synthetic ACTH) administered

Cortisol levels measured at 0, 30 and 60 minutes

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

Describe a water deprivation test

A
  1. Serum and urine osmolalities tested for 8 hours
  2. IM DDAVP (desmopressin - an anti-diuretic) is administered
  3. Serum and urine osmolalities tested for 4 hours
  4. If urine/serum osmolar ratio > 2 then this is normal, any less confirms Diabetes inspidus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How are pituitary tumours classified based on size?

A

= 1cm microadenoma

> 1cm macroadenoma

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

Which cranial nerves are potentially most impacted in a pituitary tumour?

A

CN 3, 4 and 6

18
Q

What is bitemporal hemianopia?

A

Loss of peripheral vision

19
Q

What causes bitemporal hemianopia?

A
  1. Nasal retinal fibres detect peripheral light
  2. These fibres cross over at the optic chiasm which can be compressed by a pituitary tumour
  3. Hence, peripheral vision is lost
20
Q

What are the two main causes for prolactin increases?

A
  1. Physiological
  2. Drugs
21
Q

What are the main physiological causes for prolactin increase?

A
  1. Breastfeeding
  2. Pregnancy
  3. Stress
  4. Sleep
22
Q

Which types of drugs can cause increases in prolactin?

A
  1. Dopamine antagonists (metoclopramide)
  2. Antipsychotics
  3. Antidepressants
  4. Oestrogen, cocaine etc
23
Q

What are the key pathological reasons as to why prolactin may increase?

A
  1. Hypothyroidism
  2. Stalk lesions (iatrogenic or RTA)
  3. Prolactinoma
24
Q

How does the timing of presentation of a prolactinoma differ in males and females?

A

Males - Late presentation

Females - Early presentation

25
Q

What are the symptoms of a prolactinoma in females?

A
  1. Menstrual irregularities/ammenorrhoea
  2. Galactorrhoea
  3. Infertility
26
Q

What are the symptoms of a prolactinoma in males?

A
  1. Impotence
  2. Visual field problems
  3. Headache
  4. Antertior pituitary malfunction
27
Q

What are the relevant investigations for a prolactinoma?

A
  1. Prolactin concentration
  2. MRI (size of tumour, pituitary stalk/optic chiasm damage)
  3. Visual field check
  4. Pituitary function tests
28
Q

Dopamine agonists are treatment for prolactinoma, what is the most commonly used drug?

A

Cabergoline

29
Q

What are the benefits of cabergoline in prolactinoma treatment?

A
  1. Least side effects compared with other drugs
  2. Normalises prolactin in 96%
  3. Can induce tumour shrinkage
  4. Pregnancy rates increase
30
Q

Acromegaly is due to an excess in which hormone?

A

GH

31
Q

When does giantism occur?

A

Excess GH release before growth plate fusion

32
Q

What is the typical appearance of someone with acromegaly?

A
  1. Thickened skin
  2. Large jaw
  3. Sweaty, large hands
33
Q

What other abnormalities occur with acromegaly besides appearance?

A
  1. Hypertension and CF
  2. Headaches
  3. Snoring and sleep apnoea
  4. DM
  5. Visula field abnormalities
  6. Hypopituitarism
  7. Colonic polyps and colon cancer
34
Q

What causes the headache in acromegaly?

A

Vascular effects and rapid bloodflow

35
Q

How can acromegaly be diagnosed?

A
  1. IGF-1 elevated
  2. Failure of GH to suppress <0.4ug/L (usually exceeding 1ug/L) after GTT
  3. Visual field problems
  4. CT/MRI
  5. Pituitary function tests
36
Q

How can acromegaly be treated?

A
  1. Surgery
  2. Radiotherapy (much less effective than surgery)
  3. Somatostatin analogues
37
Q

If after surgery, a patient with acromegaly still has GH levels >1ug/L after GTT which drugs may be used for treatment?

A
  1. Dopamine agonist
  2. Octreotide
  3. Pegvisomant
38
Q

What are the beneficial effects of somatostain analogues e.g. octreotide?

A
  1. Reduces tumour size
  2. Releives headaches in 1 hour
  3. Reduces GH in most
39
Q

What are the side effects of somatostain analogues?

A
  1. Local stinging
  2. Flatulence
  3. Diarrhoea
  4. Abdominal pain
  5. Gastritis
  6. Gallstones (inhiition of GB contraction)
40
Q

What is pegvisomant?

A

GH receptor antagonist

41
Q

What are the beneficial effects of pegvisomant?

A

IGF-1 decreases

42
Q

What tests/investigations should eb undertaken for an acromegaly follow up?

A
  1. BP/lipids/glucose (for CV risk)
  2. GH < 0.4ug/L (post GTT) and < 2ug/L (random)
  3. Normal IGF-1 levels
  4. Other pituitary hormones
  5. Cancer surveillance e.g. colon/tubulovillous adenoma
  6. Sleep apnoea tests

The Endocrine System (35 decks)

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