First Aid: Endocrine Flashcards
(86 cards)
What is the most common site for ectopic thyroid tissue?
Tongue
A patient presents with an anterior midline neck mass that moves with swallowing or protrusion of the tongue. What may this be?
Thyroglossal duct cyst
What is the most commons tumor of the adrenal medulla in adults and what would a patient present with?
In children?
Adults = Pheochromocytoma; Episodic HTN
Children = Neuroblastoma; rarely causes HTN
What are the layers of the adrenal cortex and how are they regulated? What secretory products does each layer release?
GFR - Zona Glmoerulosa (Renin-angiotensin), Fasiculata (ACTH,CRH), Reticularis (Acth, CRH)
“The deeper you go the sweeter it gets”
Salt (Na+) –> Sugar (glucocorticoids) –> Sex (androgens)
What is the adrenal medulla composed of and what does it release? How could you inhibit regulation of this structure?
Chromaffin Cells (derived from neural crest)
Release Catecholamines (Epi, NE)
Inhibit SANS would block preganglionic sympathetic fibers
What are the main differences between the posterior pituitary (neurohypophysis) and the anterior pituitary (adenohypophysis)?
Post Pit is from neuroectoderm and secretes vasopressin and oxytocin
Ant Pit is from oral ectoderm (rathke pouch) and secretes FSH, LH, ACTH, TSH, Prolactin, GH, melanotropin (MSH)
What three hormones are secreted from the endocrine pancreas and what are responsible for releasing them?
- Glucagon - from alpha cells, (afar on the outside)
- Insulin - from beta cells (inside)
- Somatostatin - from gamma cells (dispersed)
What is increased in an insulinoma?
C-peptide and Insulin
Exogenous insulin lacks C-Peptide
Which structures have insulin-INdependent glucose uptake?
BRICK L
Brain, RBCs, Intestine, Cornea, Kidney, Liver
What are the three main compounds that will increase insulin and what are the perils of some of these effects?
- Glucose (too much –> insulin resistance)
- Growth Hormone (ditto)
- beta2-agonists
What are three ways of inhibiting glucagon? Which of these also inhibit insulin release?
- INsulin
- Hyperglycemia
- Somatostatin (also inhibits insulin)
Analogs of what hormone can be used to treat acromegaly, and why?
Somatostatin because it decreases GH and TSH
What are the varying effects on the body based on different modes of GnRH secretion?
What would occur in a patient with pituitary prolactinoma?
Tonic GnRH suppresses HPA axis
Pulsatile GnRH leads to puberty and fertility
Prolactin decreases GnRH, in excess (symptoms of menopause!!) –> amenorrhea, osteoporosis, decreased libido
How may a prolactinoma be treated and why? What would be devastating drugs or conditions to give someone with this disorder?
Tx: Dopamine agonists (bromocriptine) b/c dop inhibits prolactin secretion
Do not give Dopamine antagonists (most antipsychotics) and estrogens (OCPs, pregnancy) as these will STIMULATE prolactin secreation
What regulates Growth Hormone Secretion?
Increase during exercise and sleep
Decrease from glucose and somatostatin
What happens to ADH levels during central diabetes insipidus and how may you treat this? What about nephrogenic DI?
Decrease in Central DI
Tx: Desmopressin (ADh analog)
Increase in nephrogenic DI b/c of mutation in V2 receptor
A patient presents with HTN, hypokalemia and decreased DHT. They are XY pseudo-hermaphrodite with ambiguous genitalia and undescended testes. Aldosterone is increased while androgens and cortisol are decreased. What is their deficiency?
17 alpha-hydroxylase - mineralocorticoids are bypassed but glucocorticoids and sex hormones are shunted off
An infant presents with hypotension, hyperkalemia and salt wasting. Aldosterone and cortisol are low, but sex hormones are normal. What deficiency is this and what compound will be elevated? How else could they present?
21-Hydroxylase deficiency - sex hormones normal but Cortisol and Aldosterone formation is shunted off (HYPOALDOSTERONE). 17-Hydroxy-progesterone will be elevated.
May present in childhood with precocious puberty or XX:virilization
A young female presents with secondary male characteristics from virilization. She also has HTN and decreased aldosterone and cortisol levels. Androgen is increased. What caused the increase in blood pressure?
11 beta-hydroxylase deficiency
elevated 11-deoxycorticosterone causes an elevated BP with low-renin
What are the six main features of increased cortisol? And what will cause prolonged secretion of cortisol?
Chronic stress leads to excess –> BIG FIB
Blood pressure INCR
Insulin resistance INCR
Gluconeogenesis, lipolysis, proteolysis INCR
Fibroblast activity DECR
Inflammatory/Immune response DECR
Bone formation DECR
A patient presents with increased serum Ca, decreased serum phosphate and increased urine phosphate. What may be elevated in this patient and what does this compound cause in excess?
Parathyroid Hormone
INCR bone resorption of Ca and PO4
INCR kidney reabsorption of Ca in DCT
INCR calcitriol production (kidney 1alpha-hydroxylase)
DECR reabsorption of PO4 in PCT
A patient presents with cramps, pain, paresthesias and carpopedal spasm. Their serum pH is elevated. WHat may be the cause for this?
Hypocalcemia from increased Ca binding to albumin
What compound could lower free testosterone leading to gynecomastia in a man? What effect would low levels of this compound have on women?
Increase in Sex Hormone-Binding Globulin (SHBG)
Hirsituism in female if decreased
What are the four functions of T3?
4 B’s, Brain maturation, Bone growth, Beta-adrenergic effects, Basal metabolic rate increase