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Flashcards in Pituitary Deck (71):
1

What is the medical term for the anterior pituitary?

adenohypophis

2

Where is the ant pit derived from?

rathke's pouch

3

What are the trophic hormones secreted from the ant. pit?

TSH
ACTH
FSH
LH

4

What are the non trophic hormones secreted from the ant. pit?

GH
PRL

5

What are the three cell types of cells seen under the the microscope of ant. pit?

Acidophils
Basophils
Chromophobe

6

What hormones are secreted from Acidophils?

Somatotrophs (GH)
Mammotrophs (PRL)

7

What hormones are secreted from basophils?

Corticotrophs (ACTH)
Thyrotrophs (TSH)
Gonadotrophs (FSH/LH)

8

What is the medical term for posterior pituitary?

neurohypophis

9

Where is the post. pit derived from?

extension of neural tissue and modified glial cells and axonal processes

10

What hormones are secreted by the post. pit

ADH
Oxytocin

11

What is the histological appearance of the post. pit?

Non myelinated axons of neurosecretory neurons

12

What is the PRL axis?

Hyp: DA-
Pit: PRL
To rest of body

(NB, DA has a negative control PRL)

13

What are the physiological causes of a raised PRL?

Breast feeding
Pregancy
Stress
Sleep

14

What drugs can increase PRL?

Dompamine agonists (metaclopramide)
Antipsychotics
Antidepressants

15

What are the pathological causes of raised PRL?

Hypothyroidism
Stalk lesions (iatrogenic,RTA)
Prolactinoma

16

What are the syptoms of raised PRL in Females?

Early presentation
Galactorrhoea (30-80%)
Menstrual irregularity
Ammenorrhoea
Infertility

17

What are the symptoms of raised PRL in Males?

Late presentation
Galactorrhoea(<30%)
Visual field abnormalities
Headache
Impotence
Ant pit malfunction

18

What investigations can be done to assess for Prolactinoma?

PRL concentration
MRI pituitary
Visual feilds
PFTs (other hormones)

19

What is being assessed in MRI pituitary for prolactinoma?

Macro/Micro (>1cm/<1cm)
Pituitary stalk involvement
optic chiasm involvement

20

What visual field defect presents in prolactinoma?

Bitemporal heminopia

21

What is the treatment for prolactinoma?

Dopamine agonist

22

Give an example of medication used to treat prolactinoma

Cabergoline (2x week)
Quinagolide (OD)
Bromocriptine (TD)

23

What dopamine agonist has least side effects?

cabergoline

24

What are the aims when using a dopamine agonist in prolactinoma?

normal prolactin
menstruation regained
pregnancy achievable
tumour shrinkage

25

What is the GH axis?

Hyp: GHRH+
Pit: GH
To rest of body

26

What condition is caused by GH excess?

Acromegaly

27

What are the symptoms and signs in acromegaly?

Thickened soft tissues (skin, large jaw, sweaty large hands)
Hypertension
Cardiac Failure
Headaches (vascular)
Snoring
Sleep apnoea
Diabetes mellitus
Local pituitary effects (visul feilds, hypopituitism)
Early CV death

28

How is acromegaly diagnosed?

IIGF1*
GTT* (glucose tolerance test)
Visual feilds
CT/MRI pituitary
PFTs

29

What happens in a GTT test?

75g oral glucose
Check GH every 30 mins for 2 hours

30

What should happen in a normal GTT test?

GH suppresses to<0.4ug/l after glucose

31

What happens in an acromegaly GTT?

GH unchanged/no suppression
Paradoxical rise
GH remains >1ug/l after glucose

32

How is acromegaly treated?

Pituitary surgery
external radiotherappy to pit. fossa
Retest GTT (GH1 needs drugs)

33

What drugs are used to treat acromegaly?

Dopamine agonist
Somatostatin analogue
GH antagonist (last line)

34

What use do somatostatin analogues have in acromegaly?

Reduces GH
Tumour shrinkage (30-50%, can reexpand)
Pre-op (relieve headache in 1 hr, improved outcome)

35

What are the side effects of somatostatin analogues?

Local stinging
Short term: flatulence, diarrhoea, abdo pain
Long term: Gastritis, gallstones

36

Give examples of somatostatin analogues and administration

Octreotide (SC TDS)*
Sandostatin LAR (IM 1/28 days)
Lanreotide autogel (IM 1/28 days)

37

What dopamine agonist is used in acromegaly and what doseage is given?

Cabergoline
>3g weekly

38

What is the efficacy of cabergoline in acromegaly?

GH <2ug in 15%
better if co-secreting prolactin

39

Give an example of a GH antagonist

Pegvisomant

40

What is the tumour response to pegvisomant?

Tumour does not decrease
May increase in size

41

What is the IGF-1 response in pegvisomant?

decreases but serum GH may increase

42

What is assessed in an acromegaly follow up?

Check GH and IGF-1 are clinically safe levels
Check other pit hormones esp thyroid
Cancer surveillance (colon and tubulovillous adenoma)
CVS risk
Sleep apnoea

43

What is the cortisol axis?

Hyp: CRH+
Pit: ACTH+
Adrenal: Coritsol
To rest of body
NB, negative feedback

44

What condition is caused by excess cortisol?

Cushing's Syndrome

45

What are the symptoms of Cushing's caused by excess cortisol?

Protein loss
-myopathy
-osteoporosis (fractures)
-thin skin (striae, bruising)
Altered CHO/Lipid metabolism
-DM and obesity
Altered psyche
-phycosis, depression

46

What symptoms of cushing's are caused by excess mineralocorticoid?

Hypertension
Oedema

47

What symptoms of cushing's are caused by excess androgen?

Virilism
Hirsutism
Acne
Oligo/amenorrhoea

48

How is cushing's different to obesity?

Thin skin
Proximal myopathy
Frontal balding in women
Chemosis
Osteoporosis

49

What are the signs of cushing's?

Moon face
red plethoric cheeks
inceased abdominal fat
easy bruising
poor wound healing
procximal myopathy
thin skin
buffalo hump

50

what condition's are those with cushing's more prone to?

Benign intracranial hypertension
Cataracts
AVN femoral head
Hypertension
Osteporosis
Hyperglycaemia

51

What are the screening tests for cushing's?

(High dose)overnight 1mg dexamethasone suppression test
Urine free cortisol
Diurinal cortisol variation

52

How does overnight 1mg dexamethasone work in a)normal b)cushing's?

a)cortisol 100nmol/l next morning

53

What are the normal values for urine free cortisol?

24 hr urine collection
Total<25

54

What is the definitive test for cushing's?

Low dose dexamethasone suppression test

55

How does low dose DST work?

2mg/day for 2 days dexamethasone
Cortisol s

56

What can cause cushing's?

Pituitary malfunction
Adenoma of adrenal
Ectopic thymus/lung/pancreas
Pseudo (steroid medication, alcohol and depression)

57

What tests would show a pituitary origin for cushing's?

Abn low dose dexa test
ACTH <300
High dose dexa test supresses by 50%

58

What tests would show an adrenal origin for cushing's?

Abn low dose dexa test
ACTH<1
Nil suppression high dose dexa test

59

What tests would show an ectopic origin for cushing's

Abn low dose dexa test
ACTH>300
high dose dexa Nil suppression

60

What is the treatment for
A)pituitary cushing's
B)Adrenal cushing's
C)ectopic cushing's?

A)hypophysectomy, external radiotherapy if reoccurs

B)adrenalectomy

C)remove source or bilateral adrenalectomy

61

What drug treatment is used in chushing's?

Metyrapone (waiting for radiotherapy to work, S/E common)
Ketoconazole
Pasireotide (somatostatin analogue)

62

What are the characteristics of pan hypopititarism and why?

Anterior:
Growth failure:GH
Hypothyroid: TSH
Hypogonadism: LH/FSH
Hypoadrenal: ACTH

Posterior:
Diabetes Insipidus

63

What are some causes of pan hypopituitarism?

Pituitary tumours
Secondary mets (lung, breast)
Granulomatous disease (TB, sarcoidosis)
Vascular (polyarteritis)
Trauma
Autoimmune (Sheenan post pregnancy)

64

What are the symtoms of anterior pan hypopituitarism?

Menstrual irregularities F
Infertility
Impotence
Gynaecomastia M
Abdo obesity
Loss facial hair M
Loss axillary and facial hair
Dry skin and hair
Hypothyroid faces
Growth retardation (C)

65

What are the baseline pituitary function tests?

fT4, TSH
Oestradial/Testosterone, LH, FSH
GH, IGF-1
PRL

66

What is the therapy for pan hypopituitarism?

Replacement therapy
Thyroxine
Hydrocortisone
ADH
GH (daily SC injection)
Sex steroids (Oest/prog pill or Testosterone)

67

What effect does GH have in adults?

decreases abdo fat
increase muscle mass and exercise capacity
improves cardiac function
decreases cholesterol and increases LDL
Increases bone density

68

What are the risks of testosterone replacement?

Prostate enlargement (NOT CANCER)-monitor by PR and PSA
Polycythaemia-FBC
Hepatitis with oral tabs-LFTs

69

What disease is cause by posterior pit insufficiency?

Diabetes insipidus
ADH

70

What are the causes of DI?

Familial (DIDMOAD-DI, DM, optic atrophy, deaf)
Acquired (idiopathic, trauma)
Rare (tumour, sarcoid, meningitis)
Nephrogenic renal resistance to ADH
Paraneoplastic syndrome

71

How is DI treated?

Desospray (nasal)
Desmopressin (oral, sublingual, IM)*

*highest to lowest dose