Pediatric Endocrine Flashcards by Danielle Dilday

describe the pathogenesis of Rickets

failure of apoptosis of the hypertrophic chondrocyte in the physeal growth plates leading to a cupping appearance of the epiphyseal ends of the bone

How well did you know this?

Not at all

Perfectly

Describe the pathogenesis of hypophosphatemic rickets

X-linked genetic disorder of PHEX gene which encodes for FGF-23

How well did you know this?

Not at all

Perfectly

T or F: maternal diabetes can cause the baby to grow faster b/c of increased GH and insulin

True

How well did you know this?

Not at all

Perfectly

what would happen if a pregie has undiagnosed parathyroid adenoma?

Hypersecretion of PTH will increase serum calcium in the mother and subsequently that of the fetus
Effect: decreased fetal PTH secretion and hypocalcemia

How well did you know this?

Not at all

Perfectly

what are the clinical presentations of congenital hypothyroidism?

6 Ps:
pot-belly
pallor
puffy-face
protruding umbilicus
protuberant tongue
poor brain development

How well did you know this?

Not at all

Perfectly

what are the lab indications of primary hypothyroidism?

High TSH & low free T4
explanation: TSH is compensating for low T4 levels

How well did you know this?

Not at all

Perfectly

what are the lab indications of secondary or central hypothyroidism?

low TSH & low T4

How well did you know this?

Not at all

Perfectly

what compound in serum is used to evaluate GH deficiency?

IGF-1

How well did you know this?

Not at all

Perfectly

What should you as the physician include in your initial work-up for evaluation of GH deficiency?

IGF-1
if IGF-1 elevated to GH suppression test and MRI of pituitary gland to rule out craniopharyngioma

How well did you know this?

Not at all

Perfectly

Define constitutional growth delay.

benign transient delay in growth that eventually catches up w/ growth and sexual developmental stages

How well did you know this?

Not at all

Perfectly

what is the main cause of chronological age > bone age?

GH deficiency

How well did you know this?

Not at all

Perfectly

what is the main cause of bone age > chronological age?

obesity

How well did you know this?

Not at all

Perfectly

Describe how obesity affects the growth plates?

obesity increases amount of estrogens due to increased aromatase activity in the presence of excess adipose tissue
estrogen inhibits apoptosis in bone-forming osteoblasts and induces apoptosis in bone-resorbing osteoclasts

How well did you know this?

Not at all

Perfectly

T or F: continuous release of GnRH stimulates subsequent release of LH & FSH.

FALSE
continuous release of GnRH inhibits release of GH & FSH
GnRH promotes LH & FSH release when released in a pulsatile manner

How well did you know this?

Not at all

Perfectly

Define Gonadarche

increased GnRH secretion in response to nocturnal LH secretion

How well did you know this?

Not at all

Perfectly

Prior to puberty, how are androgens produced?

androgens get synthesized from cholesterol in the adrenal gland and converted to estrogen by aromatases in adipose tissues.

How well did you know this?

Not at all

Perfectly

what is primary hypergonadotropic hypogonadism?

defined quantitatively as elevated gonadotropins but low sex steroid levels

How well did you know this?

Not at all

Perfectly

Define hypogonadotropic hypogonadism

low gonadotropin concentrations and low levels of sex steroid

How well did you know this?

Not at all

Perfectly

what are the most common causes of primary hypogonadism

Turner syndrome
klinefelter syndrome

How well did you know this?

Not at all

Perfectly

what are the most common causes of secondary hypogonadism?

constitutional delay of puberty
Kallmann syndrome

How well did you know this?

Not at all

Perfectly

what heart defects are assoc. w/ Turner Syndrome?

coarctation of the aorta
bicuspid aortic valve

How well did you know this?

Not at all

Perfectly

compare and contrast the different clinical presentations b/t Turner and Klinefelter syndromes.

Turner syndrome:
short stature
decreased estrogen
increased LH & FSH
ovarian dysgenesis

Klinefelter Syndrome:
tall stature
decreased testosterone
increased estrogen, LH, FSH
testicular atrophy
gynecomastia
female hair distribution

How well did you know this?

Not at all

Perfectly

what is the pathogenesis of Kallmann syndrome

failed migration of GnRH-producing neurons

How well did you know this?

Not at all

Perfectly

what are the clinical presentations of Kallmann syndrome

Anosmia
infertility
primary amenorrhea in females
lack of testicular development in males
decreased LH, FSH, & testosterone
failure to start or complete puberty

How well did you know this?

Not at all

Perfectly

What facet of turner syndrome explains assoc. heart defects?

decreased estrogen: estrogen acts on the heart to increase vasodilation and nitric oxide production this prevents the extensive aortic stiffness seen in the hearts of kids w/ turner syndrome

What is the pathogenesis of central precocious puberty

Early activation of HPA axis leading to increased FSH, LH, & subsequently estrogen

describe the pathogenesis of peripheral precocious puberty

suppressed HPA axis leading to decreased FSH, LH, but increased estrogen

what is the pathogenesis of McCune-Albright Syndrome

GNAS gene defect stimulates adenylate cyclase enzymes

what are the clinical manifestations of MA syndrome?

mosaicism- unilateral Cafe-au-lait spots fibrous dysplasia of the bones precocious puberty

what is the treatment for central precocious puberty

long-acting GnRH analogs like Leuprolide

what is the treatment for peripheral precocious puberty

antiandrogens, aromatase inhibitors, antiestrogens

Describe the pathogenesis of craniopharyngiomas

Failure of the Rathke's pouch to obliterate specific tissues during development of the anterior pituitary

where are craniopharyngiomas located

suprasellar area of the brain

what are clinical manifestations of craniophyaryngiomas?

temporal hemianopsia, GH deficiency, Diabetes Insipidus

what are the clinical presentations of congential panhypopituitarism

hypoglycemia, Jaundice, high pitched voice, proportional extremities, delayed sexual maturation, small saddle shaped nose

what are the clinical hallmarks of central diabetes insipidus?

nocturia, polydipsia, dehydration, hypotension, decreased urine osmolarity, increased plasma osmolarity, hypernatremia

what is the 1st line drug for treatment of SIADH?

Tolvaptan

T or F: there is a tanner stage 1 exclusively for males

false

Describe Tanner stage 1 that applies to both sexes

no sexual hair in pubic area pre-pubertal stage

Describe the pre-pubertal tanner stage 1 that applies exclusively to females

flat-appearing chest with raised nipple

Tanner Stage 2 normally occurs throughout what age-range?

8-11.5 yrs.

What is tanner stage II for males and females respectively?

both sexes: pubic hair appears males: testicular enlargement females: formation of breast buds

What is tanner stage III for males and females respectively?

both sexes: coarse hair across pubis sparing thigh males: penis width/glans females: breast enlargement

When does Tanner stage III normally occur?

11.5-13 yrs.

Describe Tanner Stage IV

same as Stage III with the addition of raised areola for females

when does tanner stage IV normally occur?

13-15 yrs.

What happens during stage V tanner

both sexes: coarse hair across pubis and medial thigh males: penis and testis enlarge to adult size females: adult breast contour, areola flattens

Tanner stage 5 does not typically occur until when?

pt. > 15 yrs. old

When confirming a diagnosis of congenital adrenal hyperplasia, you would expect to see increased serum levels of what?

17-OHP: for CYP21 mut. 11 deoxycortisol: for CYP11 mut.

T or F: 21-hydroxylase is only involved in the production of mineral and glucocorticoids

true CYP 21 does not influence androgen production which will increase androgen production

what are the clinical presentations of CAH (specifically 21-OH deficiency)

ambiguous genitalia lethargy hypotension salt-wasting virilization early height acceleration followed by later short stature

what are lab findings for 21-OH CAH?

hyponatremia hyperkalemia hypoglycemia elevated 17-OHP

why does 11beta-OH deficiency cause HTN?

b/c 11B-OH is only involved in synthesis of cortisol, androgen and aldosterone production increase

T or F: 17alpha-OH is only involved in androgen production.

False 17A-OH does not affect mineralocorticoid production it is however, the first enzyme involved in the conversions to make cortisol and estradiol

In primary adrenal insufficiency, what part of the adrenal glands are affected first?

zona fasciculata

What are early signs of Type I DM?

weight loss, lethargy, polydipsia, polyurina, fruity odor urine, polyphagia, N/V, abdominal pain, hyperventilation

what are the lab findings assoc. w/ Type I DM?

very low bicarb high Cr & BUN hyperglycemia positive urinary ketones (acetoacetate) positive serum B-hydroxybutyrate

Why do pt. w/ DKA typically present w/ hyponatremia?

hyperglycemia increases plasma osmolarity resulting in osmosis from the ICM to the ECM

what effects does high blood sugar have on potassium regulation?

potassium can be lost through emesis potassium wasting due to elevated aldosterone and osmotic diuresis

what effects does DKA have on phosphate regulation?

phosphate wasting-glucosuria induced osmotic diuresis metabolic acidosis shifts phosphate out of cells

DKA causes what metabolic disorder

Metabolic Acidosis w/ comp. Resp. alkalosis increased anion gap

T or F: the severity of DKA is categorized by acid-base statues?

true

what should be done prior to insulin admin. for a pt. w/ DKA?

IVF to promote volume expansion effect: increased renal perfusion & decreased glucose concentration in blood

List the clinical triad of cerebral edema?

irregular breathing HTN bradycardia

T or F: most diabetes related deaths are due to cerebral injury.

True

What is the medical managment for cerebral edema

mannitol IV and oxygen as needed intubation for resp. management

What should be monitored for pts. w/ Type 1 DM?

BP Lipid metabolism retinopathies nephropathies neuropathies

pts. w/ Type 1 DM are at high risk for what

HYPOGLYCEMIA

what is the treatment for hypoglycemic shock?

glucagon

what conditions can cause hypoglycemia in pts. w/ Type I DM

illness exercising forgetting to eat

T or F: pts. w/ Type II DM have a much higher risk of developing DKA compared to pts. w/ Type I DM

FALSE

What medical emergency, although rare, is implicated for pts. w/ both Type I & II DM

hyperosmolar hyperglycemia unlike DKA, T2DM-absecne of ketones