Endocrinology

Question 0

What two anterior pituitary hormones are increased with hypothyroidism:

Answer 0

TSH, prolactin

Question 1

Describe the hypothalamic pituitary axis:

Answer 1

GnRH -> FSH and LH
CRH -> ACTH
TRH -> TSH (-SS)
GHRH -> GH
DA -> prolactin (-SS)

From posterior pit: oxytocin and vasopressin

Question 2

What are FDA approve used for GH?

Answer 2

GH deficiency, Chronic renal failure, Turner syndrome, PWS, SGA if not caught up by age 2, ISS, noonan, AIDS wasting, SHOX def

Question 3

Triad of septo-optic dysplasia:

Answer 3

Optic nerve hypoplasia/absence
Hypothalamic insufficiency (inc DI)
Midline defect

Question 4

Define delayed puberty:

Answer 4

Males: no changes after age 14
Females: no changes after age 13 or greater than 5 years between onset and completion of puberty

Question 5

Define precocious puberty:

Answer 5

8 in girls, 9 in males

Question 6

What drugs block the release of T3 and T4 from the thyroid?

Answer 6

Lithium and iodine

Question 7

What drugs block the peripheral conversion of T4 to T3?

Answer 7

Propranolol
Glucocorticoids
Propylthiouracil
Amiodarone

Question 8

How does taking oral contraceptives affect thyroid function tests?

Answer 8

Estrogen, narcotics, hepatitis increase TBG. This increases the total T4, but TSH and Free T4 are normal

Question 10

Radio iodine uptake (RAIU) is increased in what disorders?

Answer 10

Graves’ disease increased

* distinguishes from thyroiditis which is decreased

Question 11

What is a thyroid scan?

Answer 11

Uses technetium uptake to produce a picture. Identifies a nodule as hot or cold.
(Cold nodules = Cancer, if this get fine needle aspirate)

Question 11

What bony finding supports the diagnosis of congenital hypothyroidism?

Answer 11

Delayed bone maturation. Distal femoral epiphysis is usually present at birth but is absent in congenital hypothyroidism

Question 12

When should you start therapy for congenital hypothyroidism?

Answer 12

As close to two weeks as possible

Tx: Synthroid 10-15 micrograms/kg/day

Question 13

What should mothers avoid giving to their baby with thyroxine replacement?

Answer 13

Soy formula and iron. They bind the tablets

Question 14

What are the thyroid autoantibodies?

Answer 14

Antithyrolobulin (ATA) and antithyroperoxidase (antiTPO) -* both present in hashimotos and graves

Thyroid stimulating immunoglobulin (TSI) is in graves only

Question 15

MEN I

Answer 15

Hyperplasia or neoplasia of the PPPs
Pancreas
Pituitary, anterior
Parathyroid

Question 16

MEN II A

Answer 16

Hyperparathyroidism
Pheochromocytoma
Medullary carcinoma

Question 17

most common cause of congenital hypothyroidism

Answer 17

thyroid agenesis

Question 18

2 CAH enzyme deficiencies ass with HTN

Answer 18

1. 17 alpha hydroxylase

2. 11 beta hydroxylase def (also has virilization)

Question 19

phosphorous wasting syndrome, short stature with disproportionately short LE

Answer 19

Familial hypophosphatemic rickets, x-linked.
Normal Ca, low phos, Normal PTH
Tx: oral neutral phos salts with calcitriol (1,25 Vit D increases Ca availability)((when replace PO4, develop hypocalcemia because Ca taken in to the bone)

Question 20

Labs for Hypo PTH vs Hyper PTH vs PseudohypoPTH vs PseudopseudohypoPTH

Answer 20

1. HypoPTH: Ca down/Phos up
2. HyperPTH: Ca up/Phos down
3. PseudohypoPTH: PTH resistant, ca down/phos up. AD. short and stocky
4. PseudopseudoPTH: phenotype of #3 with normal labs

Question 21

familial hypocalciuric hypercalcemia

Answer 21

AD

hypercalcemia,hypocalcemia, normal PTH

Question 22

side effects of growth hormone

Answer 22

SCFE, pseudotumor cerebri, transient carbohydrate intolerance, transient hypothyroidism

Question 23

21 OH deficiency

Answer 23

75% salt wasters, female ambiguous genitalia, 2 wk old adrenal crisis, elevated 17 OH progesterone

Question 24

upper-to-lower segment ratios

Answer 24

``` infants (legs relatively shorter) U:L 1.7 children U:L 1.0 puberty U:L 0.85-0.95 Marfan low U:L achondroplasia high U:L ```

Question 25

pseudohermphrodites

Answer 25

"overdone female" - exposure to androgens, normal internal structures, external masculinized "underdone male" - androgen insensitivity, breasts, internal male, undervirilized

Question 26

Denys-Drash

Answer 26

46 XY, defect SRY, no testicular fxn/no MIS. internal female structures. renal failure by 3, Wilms Tumor

Question 27

5 alpha reductase deficiency

Answer 27

raised as female until puberty testes produce testosterone only during puberty, +MIS. +female external until puberty, male internal structures/external virilized during puberty.

Question 28

46 XY, uterus and fallopian tubes but no ovaries (no estrogen), virilized, cryptochordism

Answer 28

persistent mullerian duct syndrome

Question 29

primary amenorrhea, external female genitalia "blind vaginal pouch" with intraabdominal testes that release testosterone

Answer 29

androgen insensitivity | defect in androgen receptor, XY, inc testosterone

Question 30

testing for Cushing syndrome

Answer 30

1. 24 hr urinary free cortisol (high) 2. if unclear (obesity vs Cushings) low dose dex suppression. check cortisol level which will be >5 (cant suppress) 3. ACTH dep vs indep, do high dose dex test which will suppress ACTH dep

Question 31

What is ACTH stim test used for?

Answer 31

differentiate 1 and 2ndary Adrenal insufficiency 1. healthy: aldosterone should double from a respectable base value (around 20 ng/dl) 2. primary: base value is usually in the mid teens or less and rise to less than double the base value 3. secondary: doubling to quadrupling from a low base aldosterone value

Question 32

SIADH

Answer 32

low serum Na, decreased UOP, euvolemic Urine Osm>serum Osm Urine Na>20 meq/L Tx: fluid restriction

Question 33

MEN 2B

Answer 33

pheochromocytoma, medullary thyroid cancer, and neurofibromas

Question 34

DI

Answer 34

increased UOP, hypernatremia urine Osm

Question 35

cerebral salt wasting

Answer 35

low serum Na, increased UOP, hypovolemic | Urine Osm>serum Osm

Question 36

Conns syndrome

Answer 36

adrenal adenoma, leading to hyperaldo

Question 37

Therapy for neonatal graves

Answer 37

Methimazole, propranolol, iodine

Question 38

Levothyroxine starting dose

Answer 38

Newborn 10-15 micrograms/kg/day | Adults 2-3 micrograms/kg/day

Question 39

what meds should pt with urticaria pigmentosa avoid

Answer 39

narcotics, radiocontrast material, NSAIDS | -pigmented lesions that turn into hives and blisters especially with rubbing, typically described in first 6 mo of life