pituitary summary Flashcards
(139 cards)
1
Q
what are the 4 roles of cortisol?
A
increases BG levels
increased body fat
defend body against infection
helps body response to stress
2
Q
how to do synachten test
A
- measure corisol @ 0, 30 and 60 minutes
- expect cortisol to reach 500 + increase by 150
- if not, insufficient
3
Q
how to do an insulin stress test / prolonged glucagon test?
A
- not in epilepsy
- cortisol + GH response every 30 mins for 2-3 hours
- normal cortisol >500
- normal GH >7
4
Q
how to do a water deprivation test?
A
- check serum + urine osmolarities for 8 hours then 4 hours after giving IV DDAVP
- if Ur / serum osmolarity ration >1.9 then normal
- otherwise its DI
5
Q
how to treat big pituitary adenoma
A
transsphenoidal surgery + replace hormones
6
Q
which drug increases PRL
A
metoclopramide - a dopamine antagonist
7
Q
symptoms of prolactinoma in females
A
early presentation ammerhorea galactorrhoea (milky nipples) menstruation irregularity infertility
8
Q
symptoms of prolactinoma in males
A
late presentation impotence visual field abnormality headache anterior pituitary malfunction
9
Q
how to treat prolactinoma
A
cabergoline (dostinex) - a dopamine agonist
10
Q
what are the 2 tests for acromegaly
A
IGF-1 + OGTT
11
Q
how to do OGTT test?
A
diagnostic
give 75g oral glucose (check GH 0,30,60,90,120)
normally - GH suppresses to <0.4 after glucose
acro - unchanged / no suppression
12
Q
how to treat acromegaly
A
- surgery
- somatostatin analogues (octrecitde)
- dopamine agonistst (carberholine)
- GH antagonists - pegvisomant
13
Q
what causes cushings syndrome
A
pituitary adenoma
14
Q
what are the symptmos of cushings
A
protein loss - promixal muscle wasting, OP (fractures), thin skin, bruising
altered carb/lipid metabolism
excess mineral corticoid (hypertension + oedema)
excess androgen (virsulism, hirsulism, acne, oligo/ammenhorea)
15
Q
what are the 3 screening test for cushings syndrome?
A
overnight 1mg dexamethasone - >130 is abnormal
urine free cortisol - 24 hours urine collection, total <250 = normal
diurinal cortisol cariation (midnight /8am) - in cushigns its constant
16
Q
what are the 2 diagnostic tests for cushings?
A
low dose dexamethasone test - 2day,2mg/day, cortisol <50 6 hours after last dose = no cushings, cortisol >130 definietly cushings
CRH test - >50% increase in ACTH + >20% increase in cortisol, suggestive of pituitary disease
17
Q
how to treat cushings?
A
metyrapone
ketoconazole (hepatotoxic)
pasireotide LAR
18
Q
what are the 3 causes of panhypopituitarism
A
pituitary tumours
granulomatous disease
autoimmune disease
19
Q
how to replace ADH
A
desmopray
20
Q
what is the familial cause of cranial DI
A
DIDMOAD
21
Q
how to diagnose cranial DI
A
water deprivation test
22
Q
how to treat cranial DI
A
desmospray 10-60mgc daily
23
Q
what are the 6 steps of thyroid hormone synthesis
A
- thyroglobulin synthesis
- uptake and concentration of iodine (I-)
- oxidation of iodine (I-) to iodine (I)
- iodination of thyroglbulin
- formation of MIT and DIT
- secretion
24
Q
where does idoine uptake take place
A
follicular cells
25
which step is inhibited by carbimaozole and PTU
iodine attaching to tyrosine residues on thyroglobulin to form MIT and DIT
26
which is the biologically active thyroid hormone
T3
27
how does T3/4 go from colloid to follicular cells
pinocytosis
28
are thyroid hormones hydrophilic or phobic
hydorphic - hence the need to be bound to a carrier protein
29
what are the 4 roles of thyroid hormones?
1. increase basal metabolic rate
2. increase thermogenesis
3. carb metabolism
4. protein metabolism
30
what are the outcomes of T3 + T4s sympathomimetic action and what does it mean?
they increase responsiveness to adeaenlinaand noradreanline by increasing the number of receptrs - anxiety, sweating, tachycardia -> treateed with proproanolol
31
where is D1 found
liver and kidney
32
where is D2 found
heart, skeletal muscle, CNS, fat, thyroid + pituitary
33
where is D3 found
fetal tissue, placenta, brain (not pituitary)
34
what is the anterior pituiatry called and where is it derviced from
adenohypophysis
| rathkes pouch
35
what is the posterior pituitary celled
neurohypophysis
36
which 3 cells make up the anerior pituitary
acidophils (somatotrophs - GH and mamotrophs - PRL)
basophils (corticotrophs - ACTH, thyrotrophs - TSH and gonadotrophs - FSH / LH)
chromophobe
37
which cells make up the posterior pituitary gland
non-myelinated axons of neurosecretory neurones
38
what is a craniopharyngioma
tumour of pituitary gland
derived from remnants of rathkes pouch
5-15 year olds or 6th-7ths decades
growth retardation
39
what is acute hypofunction of adrenal cortex
waterhouse fredrichen (caused by bleeding secdonary to infections, usually N meningitis)
40
what is chronic hypofcutnion of adreanl cortex
addisons
41
what is prenenolone
produces aldosterone, cortisol + Testosterone
42
what is an adraenocorical adenoma
encapsulated lesion
small 2/3cm
yellow
well differentiated, small nuclei, rare mitoses
43
what is an adraenocortical carcinoma
```
functional
mets - haematogenous
large >50g + >20cm
frequet mitoses
lack of clear cells
```
44
which bodies are found in conns
spironolactone
45
what casues acute primary adrenocortical insufficiency
rapid withdrawal of steroids
46
what causes chronic primary adrenocrotical infufficiency
addisons
47
what is addisons
adreanl cortex destruction by autoimmune reactions leading to a decrease in glucocorticoids (hypoglycaemia)
48
what is the biochem for addisons
decrease in mineralcorticoids
K+ retention
Na+ loss
49
what is the pigmentation in addisons caused by
POMC
50
what is the histology of the adrenal medulla
inervaetd by pre synpatic fibres from sympathetic NS
| neuroendocrine / chromaffin cells (secrete catecholamines)
51
what is a rare cause of secondary hypertension
phaeochromocytoma
52
what are the symptoms of phaeochromocytoma
headache, hypertension, sweating
53
how to diagnose phaeochromocytoma
urianry catecholamiens
| MRI
54
what does the 10% tumour mean
```
bilateral
extra-adrenal
not hypertensive
malignant
25% familial
```
55
how to treat phaeochromocytoma
phenoxybenzamine (A)
| propranolol (B)
56
men 2a
phaeochromocytoma
MTC
parathyroid hyperplasia
57
men 2b
```
phaeochromocytoma
MTC
meningioma
ganglioneuroma
marfan old habitus
RET mutation
```
58
zona glomerulosa produces
mineral corticoids eg aldosteron
59
zona fasciculata prodces
coritsol, corticosteroids, cortison
60
zona reticularis produces
andrognes
61
adreanl medulla produces
stress hormoens eg epinephrine
62
what does mineralcorticoids do
increased NA+ reabsorption
K+ / H+ excretion
BP regulation
regulation of extracellular volume
63
how to diagnose adrenal insufficiency
```
decreased Na
increased K+
short synacten test
ACTH levels increased
adreanl antibodies
```
64
how to treat adrenal insufficiency
hydrocortison (2 doses for diurinal rhythm)
| fludrocortisone (replace aldosterone)
65
what is seocndary adreanl insufficiency
clincal featuers same as addisons but pale skin (no increased ACTH)
66
how to treat secondary adreanl insufficiency
hydrocortison only
67
what is primary aldosteronism
autonomous production of aldosterone, independent of its regualtors (ANG2 / K+ )
68
clinical features of primary aldosteronism
significant hypertension
hypokalaemia
alkalosis
69
how to diagnose primary aldosteronism
1. confirm aldosterone excess - measure plasma aldoserone + renin + express as ratio
- if increased, so saline suppression test
- failure of plasma aldosterone to suppresss by >50 with S2 of normal saline confirms PA
2. confirm subtype - adrenal CT
70
how to manage adreanal adenoma
unilatearl laparoscopic adreanlaectomy
71
how to manage bilateral adrenal hyperplasia
MR antagonists eg spironolcatone or epelenone
72
genetics of congenitl adreanl hyperplasia
21a hydroxylase deficiency
| basal 17-OH progesterone (end product is 21aHD)
73
symptoms of CAH males and females
males - adreanl insufficiency, poor weight gain
| females - genital ambiguity
74
definition of OP
<2.5SD below adult mean
75
oral bisphosphonate example
aldendronate
| take 30 mins before breakfast with a glass of water
76
when to give drugs for DEXA score for OP
T score <2.5
77
what controls water balance and how does it work?
ADH
| makes you pee less by aborbting water from renal tubules
78
what does decreased ADH mean
decreased urine but increased concentration = increased osmolarity
79
what does decreased osmolarity mean
increased ADH
| increased urine but decreased concentration
80
what control sodium balance
steroids eg aldosterone by adrenals
81
what does decreased BP do
Na+ retention eg increased Na
82
what sodium follow water or water follow sodium?
water follows sodium
83
what are the signs of hypotronaemia
```
increased pulse
postural hypo
decreased urine output
decreaed consiousness
decreased skin tugor
soft / sunken eyeballs
dry mouth
```
84
signs of hypertronaemia
```
coughing
tiredness
SOB
pulmonary oedema
pleural effusion
swelling in ankles
```
85
causes of hypotronaemia
```
Na loss (adrenal, gut, skin)
decreased Na+ intake
decreased H20 excretion (SIADH)
increased water intake
```
86
causes of hypertronaemia
increased NA+ intake (drowning)
decreased NA+ loss (DI)
decreased H20 intake (give dextrose)
87
how do you describe the volume of ECF
half that of ICF
88
symptoms of non-osmotic SIADH
hypovolaemia
hypotension
pain
nausea/ vomiting
89
acute hypercalcaemia symtpoms
thirst
dehydration
confusion
polyuria
90
chronic hypercalcaemia
```
muscle cramps
myopathy
muslce weakness
osteopenis
depression
hypertension
pancreatitis
renal caliculi
```
91
increased Ca
increased serum PTH
increased Ca urinary output
hyercalciaemia
92
increasec Ca
increased serum PTH
decreased Ca urinary output
FHH
93
secondary hypercalcaemia biochem
decreased Ca
| increased PTH
94
malignant hypercalcaemia
increased ALK PHOS
95
indications for parathyroidectomy
end organ damage eg OP
Ca > 285
<50
eGFR <60
96
what happens in FFH
autosomal dominnat
| deactivating mutation in the calcium sensing receptor eg increased Ca required before PTH is swithced off
97
signs of hypocalcaemia
parasthesia, muscle cramps / weakness, bronchosoasm
choveks sign
trosseau sign
98
what is trosseau sign
carpopedal spasm when taking BP
99
hypocalacemia biochem
increased PTH
| decreased Ca
100
acute treatment of hypocalcaemia
IV calcium glyconate 10ml 10% over 10 minutes (in 50ml saline of dextrose)
101
causes of hypoparathyroidism
digeorge
| autoimmune hypomagnesaemia
102
what causes hypomagesaemia
Ca release from cells is dependent of Mg (MG deficiency = intracellular Ca is high, PTH release is inhibited)
alcohol, thizides, PPIs
103
what causes pseydohypoparathyroidism
GNAS1 defect causing PTH resistacne rather than failrue to produce PTH
104
pseudohypoparathyroidism biochem
```
decreased Ca
increased PTH (due to resistance)
```
105
symptoms of psueohypoparathyroidism
bone abnormalities eg mccune albright
obesity
subcutaneous calcification
bracdactyly
106
what is the biochem of pseudopseudohypoparathyroidism
no alterataion in PTH - normal Ca
107
phases of menstrual cycle
follicular
ovulation
luteal
menstruation
108
increased frequency pulsatility of GnRH
LH
109
decreased frequency pulsatility of GnRH
FSH
110
what regulates GnRH
kisspeptin + GnRH neurones
111
whcih day is ovulation
14
112
what does FSH lead to
growth of ovarian follicles
113
what does the LH surge do
ovulation
reagultion of corpus luteum
progesterone production + Secretion
114
what does the LH surge activate
theca cells (convert androgens into oestrogen)
115
functions of oestrogen
thickens uterine wall
reagulates LH surge
reduced vaginal Ph through increased lactic acid production
decreased viscosity of cervical mucous to facilitate sperm production
116
functions of progesterone
maintains thickness of endometrium
infertile thick mucous (prevents sperm transport)
relaxes myometrium
117
what do leydig cells
secrete testoserone in respone to LH
118
what do sertoli cells do
support germ cells during their development into spermatozoa
119
what do germ cells do
differentiate into spermatozoa
120
symptoms of PCOS
worse on weight gain
hiruitism
increased androgens, increased LH, impaired glucose tolerance
121
diagnosis of PCOS
2/3 of
chronic anovulation
polycystic ovaries
hyperandrogenism
122
what causes premature ovarian failue adn what are the symptoms?
turners 45 XO
hot flushes, night sweats, atrophic vaginitis
increased FSH, LH and low oestridiol
123
what is hydrosalpinx
blocked fallopian tube with water fluid
| abdo pain, vaginal discharge, painful sex
124
what is endometriosis
presence of endometrial glands otuside the uterine cavity
| dsmennhorea, painful sex, painfeul defeacation, chronic pelvic pain, chocolate cysts
125
what is non-obstrctive male fertility
eg kleinfelters / undescended testes
increaed LH and FSH
dcerased testosterone
126
management of female infertility
weight loss
folic acid
10mg of vit d
127
how to treat chamydia
doxycyline
128
features of rubella
rash
microcephaly
patent ductus arteriosus
cataracts
129
treatment of male infertility
sperm analysis
| surgery to obstructed vas deferent
130
group 1 ovulatory disorder
hypothalamic pituitary failure 10%
| stress, exercise, kallmans syndrome, anorexia
131
biochem of group 1
decreased FSH
decreased LH
decerased osteogen
normal PRL
132
mangement of group 1
bmi >18
pulsatile GnrH
gonadotrophin daily infections
133
group 2
hypothalamic pituitary dysfuntion (85% PCOS)
134
managemnet of group 2
clomifene citrate
135
diagnosis of group 2
2 of oligo/ammerhoea
polycystic ovaries (>12 2-9cm)
signs of hypergonadism
136
group 3
ovarian failure
| menopause / premature ovarianfalure
137
groupo 3 biochem
increased gonadotrophins, decreaeed oestrogen (menoause)
138
lambda sign
non identica
139
T sign
identical
