Disturbances of Adrenal hormones secretion Flashcards
Hypersecretion of Aldosterone is divided into:
- Primary hyperaldosteronism (conn’s Syndrome): tumor in zona glomerulosa secreting excess mineralocorticoids
- Secondary Hyperaldosteronism: in heart failure, Liver cirrhosis or nephrosis –> elevated RAAS
- Glucocorticoid-remediable Aldosteronism (GRA): genetic error causing Zona glomerulosa to be hypersensitive to ACTH (increased All steroid hormones on adrenal gland including Aldosterone)
Explain why liver cirrhosis causes secondary hyperaldosteronism
Decreased Aldosterone reduction and conjugation —> Accumulates (excess)
Explain why Nephrosis causes secondary hyperaldosteronism
- Decreased Albumin in blood (albuminuria)
- leading to decreased osmotic pressure
- edema —> Aldosterone secretion
Features of Hyperaldosteronism
Hypokalemia, leading to:
* Hypokalemic nephropathy –> polyuria
* Hyperpolarisation –> Muscle weakness
* Metabolic Alkalosis (due to H+ excretion) —> decrease plasma Ca2+ —> Tetany
* inhibition of insulin secretion —> decrease glucose utilisation (worsens DM)
Hypertension, cause d by Na+ & water retention –> Expansion of ECFvolume
Explain why in Primary Hyperaldosteronism (conn’s Syndrome) , there is no edema == there is Escape phenomenon
Due to Atrial Naturitic Peptide (ANP):
1. Due to expansion of ECF, central venous pressure increases
2. this stimulates secretion of ANP
3. ANP balances out Na+ & Water retaining effect of Aldosterone by:
* Decrease responsivness to Zona glomerulosa
* Inhibit renin secretion
* Increases GFR & Inhibits Na+ reabsorption
Explain why secondary effects of Glucocorticoid-remedied Aldosteronism (GRA) are minimal
GRA causes secretion of All adrenal steroid hormones —> glucocorticoid corrects effect of Aldosterone
Name disease of glucocorticoid Hypersecretion
Cushing’s Syndrome
Causes of Cushing’s Syndrome
- ACTH independent: Adrenocortical tumors
- ACTH dependent: Bilateral hyperplasia of Adrenal cortex secondary to Hypersecretion of ACTH
- Adminstration of excess cortisone
Levels of ACTH in ACTH independent cushing’s syndrome
Low, due to negative feedback mechanism
Levels of ACTH in ACTH dependent cushing’s syndrome
High
effect of Cushing syndrome on metabolism
Protein metabolism–> Catabolic:
* Thin skin, fragile capillaries, easy bruising
* thin hair
* poor wound healing
* Osteoprosis
* Muscle atrophy
* Suppressed immunity
Fat Metabolism:
* Trunkal obesity —> Moon face & Buffalo hump
* Purple striae in abdomen: Stretch of thin skin by fat, showing underlying vessels
* Hyperlipidemia & ketosis
Carbohydrate Metabolism:
* Increase Gluconeogenesis & decreases peripheral glucose utilisation —> Hyperglycemia (& DM)
effect of Cushing’s syndrome not related to metabolism
CNS:
* Increases apetite
* insomnia
* euphoria
Mineralocorticod effect (when excess) —> Hypertension
Excess Androgen –> Acne & facial hair
Excess ACTH (in ACTH dependent Cushing’s) –> pigmentation (has melanocyte stimulating activity)
Hypersecretion of Adrenal Androgens in Adult females is called:
Adreno-genital syndrome
Hypersecretion of Adrenal Androgens in intrauterine females is called:
Female pseudohermaphrodite
Charactaristics of Adreno-genital syndrome
- facial hair growth
- deep voice
- acne
- balding
- Masculine distribution of body hair
- Atrophy of breast
- Loss of menses
- Enlargement of clitoris
- Masculine muscle development
Charactaristics of Female pseudohermaphrodite
Masculinized female genitalia:
* Fetus has ovaries with male type of external genitalia
Charactaristics of Adrenal Androgens hypersecretion in prepubertal male
- Early development of secondary sexual charactaristics
- Rapid development of male sexual orgnas with no growth of testis –> precocious pseudopuberty
detection of hypersecretion of Adrenal Androgens can be done by:
17-ketosteroids urine level
Disease of hyposecretion of Adrenocortical Hormones is called:
Addison’s disease
Causes of Addison’s syndrome
- Autoimmune –> Atrophy of adrenal cortex
- Tuberculosis
- Cancer
Features of Addison’s syndrome
Cortisol deficiency:
* Decreased resistance to different types of stress
* Decreased fasting glucose levels
* increased Eosinophils & Lymphocytes
* decreased neutrophils
* Depressed metabolic functions
* Increased ACTH by negative feedback mechanism —> Pigmentation
Aldosterone deficiency:
* Hyponatremia
* Hyperkalemia
* H+ retention
* polyuria
Adrenal Androgen deficiency:
* Loss of pubic and axillary hair in females
* Anemia (decreased RBCs production)
Charactaristics of Addisonian crisis
body responds to stress by:
* Collapse
* Shock
* Hyperkalemia
* Hypoglycemia
failure to resist stress
Emergency treatment for addisonian crisis
- Cortisol
- isotonic NaCl infusion
Causes of Acute Adrenal insufficency
- Waterhouse-friderichsen syndrome: adrenal hemorrhage caused by severe infection and meningococcal septicemia
- Sudden withdrawal of Corticosteroid therapy
