3/8 endo Flashcards
How does excess cortisol lead to HTN?
- up-regulates alpha-1 receptors on arterioles.
- has slight mineralocorticoid ability.
Dexamethasone suppression test
- low dose suppresses ACTH =
- high dose (8mg) suppresses ACTH =
- no suppression w/high dose (8mg) =
- low dose suppresses ACTH = normal
- high dose suppresses ACTH = pituitary adenoma
- no suppression w/high dose = ectopic ACTH prod.
How does excess cortisol lead to osteoporosis?
-cortisol dec. osteoblastic activity
CRH stimulation test
- differentiate btwn a pituitary adenoma and ectopic source.
- an ectopic source will not increase cortisol production in response to CRH b/c the pituitary is super suppressed by all the negative feedback of the ectopic ACTH.
- the pituitary adenoma will make even more ACTH and thus cortisol in response to CRH b/c its negative feedback mechanism is obviously fucked up which is a key property thats allowing it to pump out all of this ACTH in the first place.
Inoperable Cushings
-Tx:
Ketoconazole
Primary or secondary hyperaldo
-Tx:
-surgery (primary) or spironolactone
Which bug has been known to destroy the adrenals?
TB
Waterhouse-Friderichsen syndrome
-potential causes?
-Neisseria meningitidis septicemia, DIC, and endotoxic shock
Resting tone on vasculature?
- sympathetic
- hence neurogenic shock - you lose that sympathetic tone.
Neuroblastoma
- originates from what tissue?
- presentation?
- Neural crest cells
- abdominal distension and a firm, irregular mass B that can cross the midline (vs. Wilms tumor, which is smooth and unilateral).
- it does not cause HTN like pheo does.
Neuroblastoma
- what is increased in urine?
- associated w/which oncogene?
- Homovanillic acid (HVA) = breakdown product of dopamine.
- N-myc
Homovanillic acid (HVA)
- inc urinary levels in what disease?
- HVA is breakdown product of what?
- neuroblastoma
- breakdown product of dopamine.
*dopamine = precursor to catecholamines.
Neuroblastoma
- bombesin + or -
- what do you see on histology?
- bombesin + (tumor marker)
- rosettes & classic small, round, blue/purple nuclei.
pheochromocytoma
- arise from what cells?
- what color is it usually?
chromaffin cells
- neural crest cells
- brown - the adrenal medulla is usually brown.
pheochromocytoma
-rule of 10s
Rule of 10’s: 10% malignant 10% bilateral 10% extra-adrenal 10% calcify 10% kids
*More than 70% of cases of pheochromocytomas
are bilateral when familial.
pheochromocytoma
-associated w/which diseases?
-Associated with von Hippel-Lindau disease, MEN 2A and 2B.
pheochromocytoma
-Tx:
Irreversible α-antagonists (phenoxybenzamine) and β-blockers followed by tumor resection.
- α-blockade must be achieved before giving
- β-blockers to avoid a hypertensive crisis.
Hyperthyroidism
- diarrhea or constipation?
- inc or dec reflexes?
- diarrhea
- inc. reflexes
hyperthyroidism
- whats the skin & hair like?
- hypo or hypercholesterolemia?
- Warm, moist skin; fine hair
- Hypocholesterolemia (due to inc. LDL receptor expression). *you’re basically burning more fuel.
hyperthyroidism
- calcium level?
- blood glucose?
- hypercalcemia (inc. burn resorption).
- hyperglycemia (gluconeo & glycogenolysis going on).
dyspnea on exertion
-Sx of hypo or hyperthyroidism
hypothyroidism
large fontanels & macroglossia in children.
-hypo or hyperthyroidism?
hypothyroidism
Whats the most common cause of myopathy?
hypothyroidism
- myoedema will be present (edema of muscle s/p percussion), inc. creatine kinase, + other hypothyroid Sxs like weight gain, fatigue, etc.
- will present w/myalgia, proximal muscle weakness, & cramping.
Abs found in hashimotos thyroiditis
- anti-thyroid peroxidase
- antithyroglobulin antibodies
- anti-microsome
*they do not cause the disease, they are byproducts of the disease.