Endocrinology (7) Flashcards
causes of true endocrine disorders (3)
- Undersecretion or receptor problem (XY, testicular feminization)
- Hyperplasia (enlargement of endocrine gland)
- Over secretion (bushings)
lab tests for hormone diseases (3)
- measurement on horomone conce
- -if high=supress then measure
- -if low= stim then measure - Imaging organ producing horomones
- Serum autoantibody measurement for cause
hormone measurement methods (3)
Bioassays measure bioactivity (gold)
Immunoassays for peptide hormones
Mass spectrometry
hormones measured from hypothalamus(1), Pituitary(5), Throid (3), Adrenal (4)
hypothalmus- ADH
Pituitary- ACTH,TSH,GH,LH,FSH,Prolactin
Thyroid- t4,T3, calcitonin
Adrenal- sex, cortisol, aldosterone, catechoamines
hypothalamic disease causes (4)
anatomic abnormality
tumor
severe head injury
post surgical
what does the ant pituitary release
Thyroid stim hormone adreno cortical h luteinizing h follicle stim growth hormone prolactin
what are the post pituitary horomones
ADH (urinary retention)
Oxytocin
ADH causes what in acute and chronic def
diabetes insipidus
acute- develop in pt with known pituitary disease as result of surgery/radiotherapy
chronic- more than 1 month (perminent disease)
Causes of diabetes insipidus (4)
pituitary and hypothalmic tumors
latrogenic (surgery)
idiopathic
kidney tubule resistance to ADH
hypopituitarism- s/s actute and chronic
acute- fatigue, weakness, dizziness, nausea etc
chronic- tiredness, pallor, anorexia, weight loss
causes of hypopituitarism
Tumor (mc)
infarction
tauma
cong
Hormones released into blood in hyperpituiritism tumor
prolactin (50% of tumors) GH ACTH (cushings) LH/FSH non functional (20%)
what does hyperprolactinaemia cause
- infertility
- visual probs
possible causes of smallness
- primary hypothyroidism
- glucocorticoid excess
- hypopituitarism
- growth hormone decreased
- growth hormone resistance
lab assessmentt of GH
Stim tests using: Arganine, insuline, clonidine, l dopa etc
What is turners syndrome
low GH causing small stature
- webbed neck
- widley spaced nips
- coartication of aorta
- wide carrying angle
- primary amenorrhea
Growth hormone excess diseases/ could be due to (4)
- pituitary tumor
- congenital adrenal hyperplascia
- hyperthyroidism
- klinefelter syndrome
Adverse effects of GH therapy
Creutzfeldt jacob disease lukemia/cancer incidence acromegaly personality changes SCFE
Acromegaly hormone causes
GHRH increases GH
Somatostatin decreases GH
most effect of GH is seen after GH metabolism to IGF1
how to test for GH disease
inhibit GH and see if oral glucose response causes no response
if thyroid disease is in your genes what symptoms will u see
premature graying hair
hair loss
left handedness
dyslexia in males
thyroid function and control
- what is released and what does it stim
- feedback
thyrotropin releasing hormon stims TSH from ant pituitary
-free t3/t4 supresses TRH
biologically active from of thyroid hormones
t3
t4
-t3 is 3-4x more biologically active
thyroid functioning testing
Serum/plama TSH - usually the only test needed
Free T4- confirmatory test
key aspect with thyroid disease and lab data
Can be thyroid disease w normal serum thyroid hormone levels as there is a lag phase (lots of thyroid hormone is stored in fate)
clinical features of hypothyroid
letharygy, fatigue, sleepiness slow pulse cold intolerance weight gain dryness hoarness
etiology of hypothroid
autoimmune destruction of thyroid (hashimoto)
surgical tx
radiation of thyroid
hypopituitarism
mayo clinic testing protocol TSH
undetected- hyperthyroid
sub normal- borderline
normal seum TSH- no more tests
Increased serum TSH-hypothyroid
hashimotos thyroiditis- age, gender etc
older W (W;M 10:1) in 50% of Hashimotos the thyroid becomes under active
in systemic illness serum TSH is what
TSH is decreased
clinical features of hyperthyroidism
Heat intolerence weight loss palpitations fatigue Exophthalmos (usually women 20-45 years of age complain or sore, gritty eyes, irritability etc
causes of hyperthroid
diffuse toxic goiter (graves disease)
Solitary or multiple toxic adenoma
thyroiditis
iodine/iodine containing drugs
What are thyrotropic-receptor antibodies
IgG against TSH receptors seen in Graves disease
How to test for thyroid cancers
Tests for Serum TSH
Then i131 uptake
Adrenocorticotrophin (ACTH) release from pituitary is caused by
corticotropin releasing horomone from hypothalamus in respnse to:
- cortisol decrease in plasma
- stress
- glucose decrease
- bac pyrogens
outer/middle/inner layers of adrenal and what they make
outer- zona glomerulosa= aldosterone
middle- zona fasciculata= corticosteroids, androgens, oestrogens
Inner- zona reticularis= corticosteroids, androgens oestrogen
medulla makes catecholamines
Hypoadrenalism (addisons disease) s/s
- low blood pressure
- low plasma sod
- high plasma pot
- low plasma cortisol
- letharagy
- anorexia
- pigmintation of hand creases
hypoadrenalism etiology (3)
Autoantibodies (mc)
Infections
Long term steroid use
Hypoadrenalism (addisons) lab abnormalities
Serum Na decreased Serum K increased No serum cortisol response to ACTH low serum glucose serum urea increased
Hyperadrenalism hormones to note
cortisol
adosterone
adrenal androgens
Cortisol effects (5)
- gluconeogenesis
- Increased pro breakdown
- anti inflammatory
- Haematopoiesis
- lipolysis
what is hypercosticsol called and population
Cushings syndrome
Male to femal 1:4
Hypercostisolism symptoms
- increased abdominal fat 94%
- high blood pressure 82%
- Secondardy diabetes mellitues 85%
- Sexual malfunction 75%
- Baldness and facial hair in women 75%
Causes of hypercortisolism (5)
Pituitary tumor (cushings) Adrenal tumor (cushings) Lung tumor (ectopic acth) iatrogenic stress
lab dx in hypercostisol
serum cortisol increased
low dose dexamethasone used to supress serum cortisol, Then high dose dexamethasone to supress serum cortisol (to distinguish cushings disease from syndrome)
How to tell cushings disease from ccushings syndrome
ACTH iis increased in CD but not in syndrome
cushings syndrome symptoms
face changes buffalo hump cardiac probs obesity purple stretch marks
hyper adrenal symtoms
ovarian or adrenal carcinomas give excess androgens (hair on face and virillization in women)
- polydipsia/polyuria
- weakness/mm cramps
- mild to mod high bp
Adosterone excess primary (lab, cause)
rare
-serum aldosterone increased and serum renin decreased
Aldosterone excess secondary lab
serum aldosterone and serum renin increased
adrenal hyperplasia screening tests + confirmatory tests
serum k decreased, urin k increased
confirm
- normal saline IV supresses plama aldosterone
- captopril supresses
hyper adrenaline cause
90% in adrenal medulla (pheochromocytoa)
Pheochromocytoma symptoms
headache
excess sweat
palpatins
hypertension
dx tests for pheochromocytoma
urine metanephrine
urine vanillyl mandelic acid (VMA)
–both increased substatially
