Endo week 11 Flashcards
what is the major factor controlling AVP release?
what is the major factor controlling AVP release?
Answer: plasma osmolality
what kind of receptors found where stimulate the release of ADH?
what kind of receptors found where stimulate the release of ADH?
Answer:
hypothalmic osmoreceptors in hypothalamus stimulate it to release ADH from posterior pituitary (primarily)
hypervolemia are what and are found where?
hypervolemia are what and are found where?
Answer:
are: ‘pressure receptors’
where: left atrium & pulmonary veins
do what: inhibit ADH when stretched.
what are factors affecting ADH release?
what are factors affecting ADH release?
Answer:
- increased serum osmolarity [greater than 280 mOsM]
- decreased atrial stretch due to low blood volume
- decreased blood pressure [ECF volume]
- angiotensin II
what factors inhibit ADH release?
what factors inhibit ADH release?
Answer:
- decreased serum osmolarity
- ethanol
- increased atrial stretch due to high blood volume
what are the 4 different kinds of diabetes insipidus?
hint: c. n.d.g.
what are the different kinds of diabetes insipidus?
Answer:
- Central (hypothalamic) DI: lack of ADH secretion
- Nephrogenic DI: kidney receptors are not working
- Dipsogenic DI: drink too much water, so you pee alot
- Gestational DI: deficiency of ADH in pregnancy
what is the main feature of diabetes insipidus?
do patients with diabetes insipidus have normal glucose levels?
what is the main feature of diabetes insipidus?
Answer:
Large volume of dilute urine (hypotonic) & (tasteless) because either ADH deficiency or kidney failure
patients with DI have normal glucose levels.
what is the purpose of the water deprivation test and what is the chemical used?
what is the purpose of the water deprivation test and what is the chemical used?
Answer:
- to differentiate between Cranial DI and Nephrogenic DI
- synthetic AVP analogue (DDAVP)
if DDAVP = concentrated urine –> Cranial DI
if DDAVP = no concentrated urine –> nephrogenic DI
when does Syndrome of Inappropriate Antidiuretic Hormone (SIADH) occur?
when does Syndrome of Inappropriate Antidiuretic Hormone (SIADH) occur?
Answer:
- when there is an unnecessary increased ADH secretion, which leads to high water retention and low Na+ in blood.
common causes of SIADH?
hint: Tu.Ec.Dg
common causes of SIADH?
Answer:
- Tumour in brain
- Ectopic production by carcinoma of lungs, pancreas.
- Drug induced (nicotine, morphine)
Factors regulating Aldosterone secretion?
Factors regulating Aldosterone secretion?
Answer: - increased K+ - Renin - Angiotensin II -
what is the site of action of ACTH?
what is the site of action of ACTH?
Answer:
- distal convoluted tubule
- collecting duct
what is the overall feature in Cushing’s syndrome?
what is the overall feature in Cushing’s syndrome?
Answer: excess glucocorticoids (cortisol)
what is the overall feature in Conn’s syndrome?
both primary and secondary hyperaldosteronism
what is the overall feature in Conn’s syndrome
Answer: excess mineralocorticoids (aldosterone)
what happens in Primary hyperaldosteronism?
what happens in Primary hyperaldosteronism?
Answer: Adrenal carcinoma
- low plasma renin
