First Aid 2010: Endocrine

Front 1

Embryologically, where does the adrenal cortex come from?

the adrenal medulla?

Back 1

cortex: mesoderm

medulla: neural crest

Front 2

Describe adrenal gland drainage (R and L)

Back 2

Left adrenal: -> L adrenal vein -> L Renal vein -> IVC

Right adrenal: -> R adrenal vein -> IVC

Front 3

Embryologically, what is the neurohypophysis (post pituitary) derived from?

the adenohypophysis (ant pituitary)

Back 3

Posterior: neuroectoderm

Anterior: oral ectoderm

Front 4

Which pituitary hormones have a common alpha subunit

Back 4

TSH, LH, FSH, and hCG

Front 5

Where are Islets of Langerhans most numerous

Back 5

in tail of pancreas

Front 6

What effect does insulin have on Na and K

Back 6

increases Na retention (kidneys)
increases cellular uptake of K

Front 7

What organs do not need insulin for glucose uptake

Back 7

BRICK L

Brain
RBCs
Intestine
Cornea
Kidney
Liver

Front 8

What is the mechanism of action in insulin secretion

Back 8

made in B cells of pancreas in response to ATP from glucose metabolism closing K+ channels and depolarizing cells

depolarization opens Ca channels in cell membrane -> increased intracellular [Ca] -> exocytosis of insulin

Front 9

Where do they act?

GLUT-1
GLUT-2
GLUT-4

Back 9

GLUT-1: RBCs, brain
GLUT-2 (bidrectional): B islet cells, liver, kidney
GLUT-4 (insulin responsive): adipose tissue, skeletal muscle

Front 10

How does 17alpha-hydroxylase deficiency manifest in a male

in a female?

Back 10

male: pseudohermaphroditism from decreased DHT

female: sexual infantilism; NL female, but lacking secondary characteristics

Front 11

Which of the GLUT transporters is birectional?

Which is insulin responsive

Which is insulin independent

Back 11

GLUT-2 is bidirectional

GLUT-4 is insulin responsive

GLUT-1 and GLUT-2 are insulin independent

Front 12

17alpha-hydroxylase characteristics

Back 12

decreased cortisol
decreased sex hormones
increased mineralocorticoids (HTN, hypokalemia)

Front 13

21-hydroxylase deficiency characteristics

Back 13

decreased cortisol
increased sex hormones
decreased mineralocorticoids (increased renin)

Front 14

11-beta hydroxylase deficiency characteristics

Back 14

decreased cortisol
increased sex hormones
decreased corticosterone (aldosterone)

maculinization
hypertension due to excess 11-deoxycorticosterone (a mineralocorticoid)

Front 15

What is a lethal consequence of 21-hydroxylase deficiency in newborns

Back 15

b/c of decreased mineralocorticoids, salt wasting can lead to hypovolemic shock

Front 16

What is a common characteristic of all the congenital adrenal hyperplasias

Back 16

adrenal gland enlargement from increased ACTH b/c of decreased cortisol

Front 17

What effect does Mg+2 have on PTH

Back 17

low serum Mg -> low PTH secretion

Front 18

What are common causes of low serum Mg+2

Back 18

diarrhea, aminoglycosides, diuretics, EtOH abuse

Front 19

What cells make PTH?

What cells make Calcitonin?

Back 19

PTH: Chief cells of parathyoid

Calcitonin: parafollicular cells (C cells) of thyroid

Front 20

What endocrine signaling pathways use tyrosine kinase?

which ones use Jak/STAT pathway intracellularly?

Back 20

tyrosine kinase: GH, Prolactin, Insulin, IGF-1, PDGF, FGF

JAK/STAT: Prolactin, GH, cytokines, colony stimulating factor

Front 21

What is the signaling pathway for GnRH, GHRH, Oxytocin, ADH (V1 receptor), TRH

Back 21

IP3

("GGOAT")

Front 22

What endocrine signaling pathway uses cAMP?

Back 22

("FLAT CHAMP") + CG
FSH, LH, ACTH, TSH, CRH, hCG, ADH (V2 receptor), MSH, PTH, Calcitonin, Glucagon

Front 23

What is the signaling pathway for ADH:

V1 receptor?
V2 receptor?

Back 23

V1 is IP3

V2 is cAMP

Front 24

What is the signaling pathway for ANP and NO (EDRF)

Back 24

cGMP

Front 25

What effect does an increase in SHBG (sex hormone binding globulin) cause

Back 25

increased SHBG lowers free testosterone -> gynecomastia

Front 26

What effect does a decrease in SHBG (sex hormone binding globulin) cause

Back 26

decreased SHBG raises free testosterone -> hirsutism

Front 27

What are the main functions of T3

Back 27

4 Bs
Brain maturation
Bone growth
Beta-adrenergic effects
increased BMR

Front 28

In what condition is there low TBG

is there high TBG?

Back 28

Low TBG: hepatic failure

High TBG: pregnancy or OCP use (estrogen increases TBG) but free T3/T4 remain the same

Front 29

Where is most T3 made

Back 29

in the blood (from T4 in peripheral tissue)

Front 30

When do you see a negative Ca+2 balance

Back 30

women during pregnancy or lactation

(intestinal Ca absorption less than excretion)

Front 31

What is the most common cause of primary hyperparathyroidism

Back 31

parathyroid adenoma

Front 32

What happens in HHM (Humoral Hypercalcemia of Malignancy)

Back 32

caused by PTH-related peptide (PTH-rp)

hypercalcemia, hypophosphatemia, phosphaturia, decreased PTH (feedback inhibition from increased Ca)

Front 33

What happens in primary hyperparathyroidism

Back 33

hypercalcemia, hypophosphatemia, phosphaturia, increased urinary cAMP, increased bone resorption, increased PTH

also, increased URINARY Ca excretion b/c of increased filtered load of Ca+2

"Stones, bones, and groans" in Osteitis fibrosa cystica (bone pain with brown fibrous tissue).
Kidney stones and PUD

Front 34

What is the most common cause of hypoparathyroidism

Back 34

thyroid surgery, or congenital

Front 35

What is the fxn of 1 alpha hydroxylase?

What increases 1alpha-hydroxylase activity

Back 35

1-alpha hydroxylase: makes active Vit D in the kidney

decreased serum Ca
increased PTH levels
decreased serum Phosphate

Front 36

#1 cause of Cushing's syndrome?

#2 cause of Cushing's syndrome?

Back 36

#1: exogenous (iatrogenic) steroids

#2: Cushing's disease due to ACTH secretion form pit adenoma

Front 37

Metyrapone

MOA?
indication?

Back 37

blocks 11beta hydroxylase

used to determine the etiology of Addison's disease by blocking 11 beta hydroxylase -> decrease cortisol -> increase ACTH
if an increase in ACTH (after metyrapone administration) causes hypercortisolism, cause is pituitary or ectopic

Front 38

What initiates the onset of puberty in both males and females

Back 38

pulsatile GnRH release from hypothalamus

Front 39

adrenal crisis

what is it?
sxs?
immediate tx?

Back 39

adrenal insufficiency in patients undergoing stress

sxs: hypotensive, tachycardic, hypoglycemic
immediate tx: corticosteorids

Front 40

How does prolactin inhibit ovulation

Back 40

1. inhibits hypothalamic GnRH secretion
2. inhibits action of GnRH on ant pituitary (and as a result inhibits LH and FSH secretion)
3. antagonizes LH and FSH action on ovaries

Front 41

Regarding cushing's syndrome, what causes have an increase in ACTH?

a decrease in ACTH?

Back 41

increase ACTH: Cushing's disease (ACTH secretion from a pit adenoma), Ectopic ACTH

decrease ACTH: exogenous steroids, adrenal adenoma

Front 42

How do you treat Conn's syndrome

Back 42

spironolactone

Front 43

What is secondary hyperaldosteronism

Back 43

kidney perception low intravascular volume -> overactive RAAS

from renal artery stenosis, chronic renal failure, CHF, cirrhosis, or nephrotic syndrome

assoc w/HIGH plasma renin (primary or Conn's has LOW renin)

Front 44

Addison's dz

Back 44

chronic adrenal insufficiency
primary deficiency of aldosterone and cortisol -> hypotension, skin hyperpigmentation (high ACTH)
characterized by Adrenal Atrophy and Absense of hormone production
involves All 3 cortical divisions

different from 2ndary adrenal insufficiency which has low ACTH, no hyperpigmentation and no hyperkalemia

Front 45

What is Waterhouse-Friderichesen syndrome

Back 45

Acute adrenocortical insufficiency

from adrenal hemorrhage assoc w/N. meningitidis septicemia, DIC, an endotoxic shock

Front 46

Pheochromocytoma?
What are the main characteristics of pheochromocytoma

Back 46

most common adrenal tumor in adults. urinary VMA and plasma catecholamine levels elevated. assoc w/neurofibromatosis and MEN Types 2A and 2B

episodic (relapse and remit); 5 Ps
Pallor
Palpitations (tachycardia)
Pain (HA)
Pressure (HTN)
Perspiration

Front 47

How do you trx pheochromocytoma

Back 47

alpha-antagonists, esp phenoxybenzamine (irreversible alpha-blocker)

Front 48

What is the most common adrenal tumor in kids?
and what are some characteristics

Back 48

Neuroblastoma

can happen anywhere along the sympathetic chain; less likely to get HTN
HVA (breakdown product of dopamine) in urine
N-myc oncogene

Front 49

What is the most common cause of hypothyroidism

Back 49

Hashimoto's thyroiditis

Front 50

Main features of Hashimoto's thyroiditis

Back 50

autoimmune, Anti-microsomal and anti-TG antibodies
-assoc w/HLA-DR5 and Hurthle cells
-lymphocytic infiltrate w/germinal centers

-slow course, may be hyperthyroid early on (thyrotoxicosis during follicular rupture)

Front 51

Cretinism
What causes sporadic cretinism

Back 51

severe fetal hypothyroidism
child is pot-bellied, pale, puffy face, protruding umbilicus, and protuberant tongue

sporadic caused by defect in T4 formation or developmental failure in thyroid formation

still common in China

Front 52

Subacute thyroiditis (deQuervain's)

Lymphocytic subacute thyroiditis

Back 52

Subacute: self-limited HYPOthyroidism, often following flu-like illness
high ESR, jaw pain, very tender thyroid, granulomatous inflammation

Lymphocytic: painless, post-partum

Front 53

Riedel's thyroiditis

Back 53

thyroid replaced by fibrous tissue -> hypothyroid

hard, pain-less goiter

Front 54

Grave's dz

When does it often present?
What is a serious complication of it?

Back 54

autoimmune hyperthyroidism; Type 2 hypersensitivity

often presents during times of stress (like childbirth)

Stress-induced catecholamine surge -> death by arrhythmia (serious complication in Graves and other hyperthyroid disorders)

Front 55

Jod-Basedow phenomenon

Back 55

thyrotoxicosis if patient w/iodine deficiency goiter is made iodine replete

Front 56

Toxic multinodular goiter

Back 56

focal patches of hyperfunctioning follicular cells working independently of TSH b/c of a mutation in TSH receptor

increased release of T3 and T4
nodules are not malignant

Front 57

What cancer is assoc w/Hashimoto's thyroiditis

Back 57

lymphoma

Front 58

What are the 3 main features of hyperparathyroidism

Back 58

stones, bones, and groans
hypercalciuria -> renal stones
hypercalcemia (bones)
groans: constipation (and weakness)

Front 59

osteitis fibrosa cystica

Back 59

part of von Recklinghausen's syndrome
cystic bone spaces filled w/brown fibrous tissue (bone pain)

Front 60

renal osteodystrophy

Back 60

secondary hyperparathyroidism
secondary to renal dz (chronic renal failure)
hypovitaminosis D -> decreased Ca absorption (but hyperphosphatemia)
increased PTH b/c of low Ca

Front 61

What is Albright's hereditary osteodystrophy

Back 61

Pseudohypoparathyroidism due to Gs alpha deficiency

autosomal dominant kidney unresponsiveness to PTH
hypocalcemia, shortened 4th/5th digits, short stature

Front 62

What is Chvostek's sign
What is Trousseau's sign

What condition are they seen in

Back 62

they both are signs of hypocalcemia

Chvostek: tapping on facial nerve -> contraction of facial muscles

Trousseau: brachial artery occlusion w/BP cuff -> carpal spasm

both seen in HYPOparathyroidism

Front 63

Sheehan's syndrome

Back 63

postpartum hypothyroidism
enlargedment of anterior pituitary (increased lactotrophs) w/o corresponding increase in blood supply -> increased risk of infarction following severe bleeding + hypoperfusion after delivery

can cause fatigue, anorexia, poor lactation, loss of public/axillary hair

Front 64

What is used to dx acromegaly

What drugs is used to trx it

Back 64

dx: failure to suppress serum GH following oral glucose tolerance test

trx: octreotide (a somatostatin), after pit adenoma resection

Front 65

What can cause central DI

What can cause nephrogenic DI

Back 65

pituitary tumor, trauma, surgery, histiocytosis X

nephrogenic: hereditary or secondary to hypercalcemia, lithium, demeclocycline (ADH antagonist)

Front 66

How do you treat central DI

how do you treat nephrogenic DI

Back 66

central: intranasal desmopressin (ADH analog)

nephrogenic: HCTZ, indomethacin, amiloride

Front 67

How do you dx central vs nephrogenic DI?

Back 67

H2O restriction --> low osmolar urine (if osmolarity increases then psychogenic water drinker)

administer desmopressin. If urine osmolarity increases, then its central DI; if not, then it's nephrogenic DI

Front 68

What are the major complications of DKA

Back 68

life-threatening mucormycosis, Rhizopus infections

cerebral edema, arrhythmias, heart failure

Front 69

How do you treat DKA

Back 69

fluids, insulin, K+ (to replete intracellular stores)

glucose if necessary to prevent hypoglycemia

Front 70

List sxs of hypoglycemia.

metabolic changes in hypoglycemia?

Back 70

1. adrenergic sxs: sweating, palpitation, tremors, hunger, and nervousness due to increased NE and Epi release
2. CNS sxs (late findings): behavioral changes, confusion, visual disturbances, stupor, and seizures

metabolic changes: hepatic gluconeogenesis, peripheral glycogenolysis, and lipolysis

Front 71

What is the most common tumor of the appendix? paraneoplastic syndrome?

Back 71

carcinoid tumor

secretes 5HT -> diarrhea, cutaneous flushing, asthmatic wheezing, and right-sided valvular disease.
high 5-HIAA in urine

Front 72

what phamacologic agents can mask the effects of hypoglycemic sxs in diabetic pts?

what pharmacologic agent is preferred in hypoglycemic agnet?

Back 72

beta blockers
beta 1 blockade: mask adrenergic sxs (sweating, palpitation, tremors, hunger and nervousness)
beta 2 blockade: block metabolic changes (hepatic gluconeogenesis, peripheral glycogen synthesis, and lipolysis)

use beta 1 blockers for diabetic pts b/c beta 2 blockade will further lower blood glucose

Front 73

What are the characteristics of carcinoid syndrome

How do you treat it

Back 73

flushing, diarrhea, wheezing, R-sided valvular dz

Treat with octreotide (somatostatin)

Front 74

MEN Type 1

Back 74

Wermer's syndrome
Parathyroid tumors
Pituitary tumors (prolactin or GH)
Pancreatic endocrine tumors (ZES, VIPomas, insulinomas)

commonly present w/kidney stones and stomach ulcers

Front 75

MEN Type 2A

Back 75

Sipple's syndrome

Medullary thyroid carcinoma
Pheochromocytoma
Parathyroid tumors

Front 76

MEN Type 2B

Back 76

Medullary thyroid carcinoma
Pheochromocytoma
oral/intestinal ganglioneuromatosis (assoc w/marfanoid habitus)

Front 77

What is the inheritance for all MEN syndromes

Back 77

autosomal dominant

Front 78

What gene is associated w/MEN Type 2A and 2B

Back 78

ret gene

Front 79

List classes of insulin analogs in the order of duration of action

Back 79

peak in 30-90 min: Lispro, Aspart
peak in 2-3 hrs: regular
peak in 12-18hrs: NPH
peak in 24 hrs: Glargine, Determir

Front 80

What type of insulin is indicated as the initial tx for DKA?

Back 80

regular

Front 81

Tobutamide

class?
toxicity?

Back 81

first generation sulfonylurea

disulfiram-like effects

Front 82

Glyburide

class?
MOA?
toxicity?

Back 82

2nd gen sulfonylurea

close K+channel in B cell membrane -> Ca influx -> insulin release

can cause hypoglycemia

Front 83

Metformin

MOA?
toxicity?

Back 83

insulin sensitizer

can cause lactic acidosis so contraindicated in renal failure

Front 84

Pioglitazone, Rosiglitazone

class?
MOA?
toxicities?

Back 84

Glitazones/thiazolidinedions

increase insulin sensitivity in peripheral tissue

weight gain, edema, hepatotoxicity, CV toxicity

Front 85

Acarbose

MOA?

Back 85

inhibit intestinal brush-border alpha glucosidases

Front 86

Pramlintide vs exenatide

Back 86

Pramlintide: decrease glucagon

exenatide: increase insulin AND decrease glucagon

Front 87

Propylthiouracil, methimazole

MOA?
clinical use?
toxicity?

Back 87

inhibit organification of iodide and coupling of thyroid hormone synthesis.
Propyluracil also decreases peripheral conversion of T4 to T3

used in hyperthyroidism

can cause agranulocytosis and aplastic anemia

Front 88

Octreotide

class?
clinical use?

Back 88

somatostain analogue

used in acromegaly, carcinoid, gastrinoma, glucagonoma

Front 89

Demeclocycline

class/MOA?
clinical use?
toxicity?

Back 89

ADH antagonist (member of tetraycycline family)

used in SIADH

nephrogenic DI, photosensitivity, abnormalities of bone and teeth

Front 90

MOA of glucocorticoids

Back 90

decrease the production of leukotriens and prostaglandins by inhibiting phospholipase A2 and expression of COX-2