CP 55 - Investigating the endocrine system Flashcards
what are the features of Cushing’s Disease?
obesity - moon face, central, shoulders
skin - thin, purple striae, bruising
hypertension, glucose intolerance, menstrual disturbances/impotence, think limbs/muscle weaknes, back pain due to osteoporosise, psychiatric disturbances - depression, psychoses
what are the principles of dynamic investigations
stimulation of hypo-function & suppression for hyper-function
what causes Cushing’s Disease?
excess of cortisol
what is dexamethason
stop acth and so almost no cortisol production if administrated
what is acth
Adrenocorticotropic hormone - precursor of cortisol which is released during stressful period
how to test for cushing’s disease?
overnight dexamethason test - dexamethason to patients at around mid-night and take measurement of cortisol level next morning - if no increase then not cushing’s if still elevated then it is cushing’s
what are some of the clinical features of adrenal failure
tiredness, weight loss, pigmentation, hypoglycaemia, abdominal pain
where is cortisol produced
adrenal cortex
what is the cause of Addison’s disease?
it is lack of cortisol ie cortisol deficiency
why does pigmentation happen in addison’s disease
acth act on pigment when activated or overproduced
what is the pitfall of T4 & T3 measurement
it has a low diurnal difference
why do you test for TSH & T4 together rather than separately
it is because they are in a dynamic system and so testing for both of them will allow you to where the problem is in the anterior pituitary gland or the actual thyroid gland
what is synacthen
artifical acth
what is the formula uesd to determine hormones in equilibrium
free hormone + protein-bound hormone = total hormone
