Pituitary function Flashcards

1
Q

posterior pituitary

A

ADH

oxytocin

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2
Q

measuring hormones

A

know whether you are expecting deficiency or excess
measure at the appropriate time of day
for deficiency measure at the peak (eg cortisol in the morning)
for excess, measure at the lowest point (eg midnight for cortisol)

often dynamic blood tests are required. try to stimulate hormones in deficiency, and suppress in the case of excess, using the bodies own negative feedback loops. eg dexamethasone test

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3
Q

pituitary disease

A

can rarely be congenital, but far more often acquired, most often by a space occupying lesion

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4
Q

ectopics

A

rare

result in hormone excess

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5
Q

optic chiasm

A

classic appearance of bitemporal temporal hemianopia in the presence of a pituitary mass

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6
Q

pituitary adenomas

A

can produce one or more hormones or none at all
can result in a picture of excess and deficiency
typical order of hormone loss in pituitary mass:
GH>LH>FSH>TSH>ACTH>prolactin
people usually become symptomatic around LH/FSH

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7
Q

opthalmoplegia

A

nerves contolling eye muscles compressed and eye muscles paralysed

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8
Q

pituitary compression caused by rupture

A

typical hormone loss
ACTH>TSH>GH>FSH>LH
vital to replace corticosteroids immediately to avoid death

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9
Q

primary

A

problem with the organ secreting the relevant hormone eg adrenals

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10
Q

secondary

A

problem higher up in the axis, eg the pituitary

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11
Q

pigmentation

A

increased ACTH increased melanocyte stimulating hormone, leading to pigmentation of the skin
this is only seen in primary conditions, as the pituitary produces higher levels of ACTH to try and stimulate hormone secretion at the target organ

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12
Q

addisonian crisis

A
hypovolaemic shock
D&V
hypoglycaemic
abdo pain
lower back pain 
afebrile
medical emergency - easily treatable, but fatal if missed
immediate priorities:
aggressive fluid resus - 1L saline stat
parenteral glucocorticoid
correct hypoglycaemia
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13
Q

hyperaldosteronism

A

stubborn high BP
hypokalaemia
low magnesium
metabolic alkalosis

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14
Q

conn’s syndrom

A

aldosterone producing adrenal adenoma (primary)

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15
Q

thyroid deficiency

A

treated with levothyroxine

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16
Q

thyrotoxicosis

A

Grave’s disease

17
Q

prolactin

A

suppressed by dopamine rather than hormonal regulation

therefore dopamine antagonists, such as antipsychotics, will result in a hyperprolactinemia

any mass in the pituitary stalk that blocks dopamine delivery from the hypothalamus to the pituitary will have the same effect

dopamine agonists to treat hyperprolactinemia

18
Q

acromegaly

A

high levels of growth hormone
stable, florid clinical features

increased interdental spacing
sweating
high BP
impaired glucose tolerance leading to DM
carpal tunnel
coarse facial features

tested by glucose tolerance test and failure of GH to respond to high blood glucose

19
Q

diabetes insipidus

A

essentially a failure of ADH (vasopressin)

central: failure of production in the pituitary
nephrogenic: failure of action on the kidney

polyuria
thirst
tend towards dehyydration
hypernatraemia (only when unable to drink sufficient to compensate the large fluid loss)

treated with desmopressin (an ADH analogue), which is essential in patients with diabetes insipidus. omission can lead to death

20
Q

multiple endocrine neoplasia

A

MEN1, MEN2