Pituitary Flashcards
What do hypothalamic neurones secrete?
pituitary hormone releasing and inhibiting factors
Hormones
What inhibits the secretion of prolactin?
dopamine
What are the five major anterior pituitary axis’?
gonadotrophin axis growth axis thyroid axis adrenal axis prolactin
What are the 2 parts of the pituitary gland?
anterior
posterior
What hormones does the anterior pituitary secrete?
TSH, LH, FSH, GH, prolactin
Where is the anterior pituitary derived from?
Rathke’s pouch
What hormones does the posterior pituitary secrete?
ADH
Oxytocin
What is pituitary adenoma associated with?
MEN1
How do you know whether a pituitary adenoma is micro or macro?
micro - <1cm
macro - >1cm
What are 3 types of a functional pituitary adenoma?
Prolactinoma
Growth hormone secreting
ACTH secreting
Symptoms associated with prolactinoma?
Infertility
Amenorrhea
Symptoms associated with a growth hormone secreting pituitary adenoma?
Gigantism
Acromegaly
Symptoms associated with ACTH secreting pituitary adenoma?
Cushing’s
bilateral adenocorticol hypoplasia
Causes of hypopituitarism…
Tumour
Congential
autoimmune
Idiopathic
What does panhypopituitarism cause in the anterior pituitary?
Deficiency of ALL anterior pituitary hormones
GH, TSH, LH/FSH, ACTH
What hormone will you be deficient of if you have Kallmann syndrome?
gonadotrophin (GnRH)
Where is a craniopharyngioma most likely to arise?
Within sella
Craniopharyngioma has a good prognosis
True or false
true
What are the symptoms of a craniopharyngioma?
Headache
Visual disturbances
What is the most common pituitary tumour?
non-functioning pituitary adenoma
What structures are at risk of being compressed if a pituitary adenoma is too big?
Optic chiasmata
CN III, IV, VI
Management for non-functioning pituitary adenoma…
Transphenoidal surgery
Hormone replacement therapy
List some physiological causes of raised prolactin
Pregnancy Breast feeding stress sleep dopamine antagonists
List some pathological causes of raised prolactin
prolactinoma
hypothyroidism
stalk lesions
List some symptoms of prolactinoma…
Female: galactorrhea, menstrual irregularity, amenorrhea, infertility
Male: impotence, visual field abnormality
What is the visual field abnormality in prolactinoma?
Bitemporal hemianopia
What is the treatment for prolactinoma?
Dopamine antagonist (cabergoline)
What hormone is in excess in acromegaly?
GH
Symptoms of acromegaly…
Giant thickened soft tissues (large jaw, hands etc) sleep apnoea/snoring hypertension headaches Diabetes mellitus Polyps - colon cancer??
What investigations are carried out in suspected acromegaly?
bloods-
IGF-1
Oral glucose tolerance test
GH levels
What is the most common cause of mortality in acromegaly?
Cardiovascular death
CF, CAD, HT
Treatment for acromegaly…
1st - trans-sphenoidal surgery
radiotherapy
somatostatin analogues
What is the aim of treatment in acromegaly?
Raise GH
Shrink tumour
What does panhypopotuitarism cause in posterior pituitary?
diabetes insipidus
List some symptoms of hypopituitarism…
Menstrual irregularities Infertility abdominal obesity loss of facial, axillary and pubic hair gynaecosmastia
Treatment for hypopituitarism…
Hormone replacement therapy: thyroxine hydrocortisone ADH GH sex steroids (pill/testeosterone)
What is diabetes insipidus?
ADH deficiency so water isn’t retained
Causes fluid imbalance
What are the symptoms of diabetes insipidus?
Thirsty
Excess urination
What investigation is carried out in suspected diabetes insipdus?
Water deprivation test
Treatment for diabetes insipidus…
Desmospray
Desmopressin
