Endocrinology Flashcards
(80 cards)
What regulates prolactin release?
Prolactin is under tonic hypothalamic inhibition by dopamine sent down the pituitary stalk Prolactin increases during sleep and with stress, lactation, and stimulation of the nipple. Antidopaminergic drugs (such as metoclopramide and phenothiazines) also increase prolactin, as does TRH; thus, prolactin elevates with primary hypothyroidism and with any inhibition in the production of dopamine from the hypothalamus (most commonly,medications).
True or false? Prolactin levels are high in hypothyroidism.
True
TRH increased prolactin
What is septooptic dysplasia?
a.k.a. de Morsier syndrome
Includes:
- Abnormality of the optic nerve (absence of the optic chiasm, optic nerve hypoplasia, orboth);
- Agenesis or hypoplasia of the septum pellucidum or corpus callosum, or both; and
- Often variable degrees of hypothalamic insufficiency
Which endocrine abnormality do you look for if a patient has a solitary maxillary incisor?
GH deficiency
Which structure is key in determining the level of pituitary involvement in a patient with an ectopic posterior pituitary?
Pituitary stalk
Patients who have an ectopic pituitary and a normal stalk have isolated growth hormone deficiency.
Patients with an ectopic pituitary and an abnormal stalk tend to have multiple pituitary hormonedeficiencies.
What is the most common tumor to cause pituitary hormone deficiency?
Craniopharyngioma
What are the clinical clues that make you suspect congenital GH deficiency?
Microphallus
Hypoglycaemia
Direct hyperbilirubinaemia
What are the classic signs and symptoms of congenital GH deficiency?
Falling height Characteristic facies develops over time - Round head and short, broad face - Frontal bone is prominent - Depressed, saddle-shaped, nose - Eyes appear to be bulging - High-pitched voice Gonads are small Facial, axillary, and pubic hair is usually sparse Intelligence is typicallynormal
What is idiopathic short stature?
Shorter
Grow at slower rate
GH levels normal
True or false? Children with constitutional growth delay typically require GH to reach their normal adult height.
FALSE
What is Russell-Silver syndrome?
Russell-Silver syndrome causes:
- Short stature
- Frontal bossing
- Triangular facies
- Shortened and incurved 5th fingers (clinodactyly)
- Asymmetry.
- SGA
- FTT
Which children with short stature are FDA approved to receive GH to help them reach a more normal height?
Idiopathic Short Stature
ie. Children who are not GH deficient but whose heights are very short (>2.25 SD below the mean), who are unlikely to reach normal heights (remaining at >2 SD below the mean), and who do not have a condition that is better treated by other means.
A child with a severe head injury 3 days ago now has severe hyponatremia; what is 1 etiology you should consider?
Neurogenic (central) Diabetes Insipidus
What is the most common medication to cause nephrogenic DI?
Lithium
How is SIADH best managed?
Fluid restrict
Tx underlying cause
Name 3 abnormal causes of tall stature?
Klinfelter
Marfans
Homocystinuria
What is Sotos syndrome?
Syndrome with rapid growth early in childhood but no evidence of an endocrine disorder.
Rare
NSD1 genes
Born above the 90th percentile and then grow rapidly in the 1st year of life to >97th percentile.
Slows around 4-5yo
Big hands, feet and head
Long narrow face, big forehead, pointed chin
How might an adolescent female present with prolactinoma?
Headache, amenorrhea, and galactorrhea
What is the best way to diagnose a prolactinoma?
MRI of sella
Which hormone is responsible for the initiation of puberty?
GnRH
After the initial sign of puberty, how long is it before menarche begins in most girls?
2-2.5 years
THELARCHE -> ADRENARCHE -> MAXIMUM GROWTH VELOCITY -> MENARCHE
When does peak height velocity occur in girls?
At breast stage 2-3, between 11 to 12yo
What is the mean menarche age?
12.5 years
What are the 1st signs of puberty in boys?
testicular enlargement > 4mL & thinning of scrotum
