Nephrogenic diabetes insipidus lack of kidney response to ADH: Congenital If blood glucose level is >200 mg/dl at 2 hrs, then highly suggestive of diabetes. …
PHYSIOLOGY
Add Cardio, Pulmonary, GI
Renal Acid/Base
1 Most tubular reabsorption occurs as a result of the active transport of
Na basolaterally Glucose, lactate, many amino acids, phosphate, H and
Cl- are co-transported with Na as it diffuses down its concentration
gradient into the tubule cell
Most substances secreted by the tubules enter the tubule lumen via active
transport
Passive diffusion of CO2 and H20 allow for reabsorption of bicarbonate
2 Central diabetes insipidus - lack of production of ADH due to:
Tumors of pituitary/hypothalamus
Posttraumatic
Idiopathic
Vascular lesions
Infection
Nephrogenic diabetes insipidus - lack of kidney response to ADH:
Congenital
Drugs - lithium, demeclocycline
Endocrine/Reproductive
1 Hypoparathyroidism is most commonly caused by damage or removal during
thyroid surgery or it is congenital
Steady decline in serum Ca2 levels show signs of increasing
neuromuscular hyperexcitability followed by hypocalcemic tetany
Lab values: Decreased serum Ca2
Increased serum phosphate
Decreased urinary phosphate excretion
2 Clinical tests for endocrine abnormalities:
Radioimmunoassays for T4, T3, TSH, cortisol, Ca2 , etc
Glucose Tolerance test: Check a fasting blood sugar level, then have
patient drink a 75 g glucose solution Re-draw blood at 30 min, 1 hr,
and 2 hrs If blood glucose level is 200 mg/dl at 2 hrs, then highly
suggestive of diabetes
Dexamethasone suppression test: Dexamethasone, a synthetic steroid, is
given to the patient at 11 pm The following day blood samples are
collected at 4 pm and 11 pm The normal response is a decrease in
circulating adrenal steroid hormones Those with Cushings will have
continued elevated levels
Radioiodine injection: Hyperthyroidism will show an increase uptake
3 Dwarfism insufficient GH and giantism excessive GH have body
habituses that remain proportional
Acromegaly excessive GH after epiphyseal plate closure results in soft
tissue overgrowth Signs include
prominent forehead, nose, mandible, ears, and enlarged hands and feet
Graves disease hyperthyroidism- heat intolerance, weight loss,
increased sweating, nervousness, tremor,
exophthalmos
Hashimotos thyroiditis hypothyroidism - myxedema, lethargy, mental
sluggishness, weight gain, cold
intolerance
Cushings syndrome hypercortisolism - Moon facies, buffalo hump,
central obesity, thin arms and legs,
striae, osteoporosis, acne, and hirsutism
Addisons disease hypoadrenalism - Anorexia, weight loss,
hypoglycemia, weakness, hypotension,
hyperkalemia, metabolic acidosis, hyperpigmentation
Conns syndrome hyperaldosteronism - Hypertension, hypokalemia,
metabolic alkalosis, decreased renin
4 Syncytiotrophoblast cells release hCG which stimulates the corpus
luteum to increase its secretion of estrogen
and progesterone By week 6, the placenta is making hormones and by
week 9 it takes over for the corpus luteum and makes the majority of the
estrogen and progesterone See figure 7-21 of BRS physiology
5 Prolactin secretion is tonically inhibited by the hypothalamus by
dopamine Hyperprolactinemia occurs due to
a prolactin secreting tumor or when the dopamine inhibition is lost
Also, when assessing hyperprolactinemia, always remember to check TRH
levels, as TRH stimulates prolactin secretion Treat with dopamine
agonists bromocriptine
6 Know everything about diabetes
Add general
Source:medicine.uchc.edu
