Endocrinology Flashcards
What regulates prolactin release?
Under inhibition from dopamine
More dopamine = less prolactin
What is the strongest osmolar stimulant of ADH osmoreceptors?
Sodium
Next is mannitol
What is the most potent known stimulus to ADH?
Nausea
What osmolality does thirst begin?
295 mOsm/kg
True or false. Prolactin levels are high in hypothyroidism.
True
Prolactin elevates with primary hypothyroidism, and with any inhibition of dopamine from hypothalamus
What is septooptic dysplasia?
Abnormality of the optic nerve, agenesis or hypoplasia of . the septum pellucidum or corpus callosum, and various degrees of hypothalamic insufficiency
Which endocrine abnormality do you look for if a patient has a solitary maxillary incisor
High likelihood of GH deficiency
Which structure is key in determining the level of pituitary involvement in a patient with an ectopic posterior pituitary?
Anterior pituitary problems
Stalk:
Normal stalk - isolated GH def
Abnormal stalk - multiple pit hormone def
What is the most common tumour to cause pituitary hormone deficiency
Craniopharyngioma
What are the clinical clues that make you suspect congenital GH deficiency?
Normal length and weight at birth
Micropenis
Hypoglycaemia
Prolonged direct hyperbilirubinaemia
Falling off growth curve after 3 years
What is idiopathic short stature?
Normal children who are short >2.25SD below mean but have normal GH secretion
True or false. Children with constitutional growth delay typically require GH to reach normal adult height
False
What is Russel Silver syndrome
Short stature, frontal bossing, triangular facies, shortened and incurved 5th fingers, asymmetry
SGA and FTT
Which children with short stature are FDA approved to receive GH to reach a more normal height
ISS who are unlikely to reach normal adult height Chronic renal insufficiency Turner syndrome Prader Willi syndrome Noonan SGA (if not caught up by 2yo) SHOX AIDs wasting syndrome
Child with severe head injury 3/7 ago, now severe hyponatremia, what aetiology should you consider
Central diabetes insipidus
What is the most common medication to cause nephrogenic DI
Lithium
how is SIADH best managed
Fluid restriction
Name 3 abnormal causes of tall stature
Klienfelter
Marfan
Homocystinuria
What is Beckwith Wiedemann syndrome
Overgrowth syndrome
Macroglossia, hepatosplenomegaly, nephromegaly, pancreatic B cell hyperplasia
Predisposed to Wilms tumor, adrenocortical carcinoma and hepatoblastoma
What is Sotos syndrome
Syndrome - rapid growth in childhood with no evidence of endocrine disorder
Born above 90th and grow rapidly in 1st year to >97th
How might an adolescent female present with prolactinoma
Headache, amenorrhoea, galactorrhoea
What is the best way to diagnose prolactinoma
MRI of sella
Risk with GH treatment
No inc risk of leukaemia
SCFE, pseudotumor cerebri, transient carb intolerance, transient hypothyroidism and scoliosis
Hormone for initiation of puberty?
GnRH
