hypersecretion of anterior piuitary hormones Flashcards
what is hyperpituitarism usually due to?
- isolated pituitary tumours
- can also be ectopic
what is hyperpituitarism associated with?
- visual field defects
- both eyes may be affected by bitemporal hemianopia as decussation of nerves is at optic chiasm
what does an excess of _____ cause?
- ACTH
- TSH
- LH, FSH
- prolactin
- GH
- ACTH = Cushing’s
- TSH = Thyrotoxicosis
- LH, FSH = precocious puberty in children
- prolactin = hyperprolactinaemia
- GH = gigantism, acromegaly
what are the physiological and pathological causes of hyperprolactinaemia?
physiological: pregnancy, breastfeeding
pathological: prolactinoma
what are the signs and symptoms in women?
- galactorrhoea
- secondary ammenorrhoea/oligomenorrhoea
- loss of libido
- infertility
what are the signs and symptoms in men?
- galactorrhoea uncommon
- erectile dysfunction
- loss of libido
- infertility
what is the pathophysiology of treatment?
dopamine from dopaminergic neurones binds to D2 receptors on lactotrophs
switches off prolactin secretion
how do D2 receptor agonists work?
- drugs deliverately inhibit prolactin release
- dec. prolactin secretion and reduce tumour size
what are the side effects of these drugs?
- nausea/emesis
- postural hypotension
dyskinesia - depression
- pathological gambling
name 2 D2 receptor agonists
- bromocriptine
- cabergoline
what is excess GH called in children and adults?
childhood = gigantism adulthood = acromegaly
describe the progression of acromegaly
insidious
what happens when acromegaly is untreated?
associated with inc. morbidity, mortality
what grows in acromegaly?
- periosteal bone
- cartilage
- fibrous tissue
- connective tissue
- internal organs
what are the clinical features of acromegaly?
- excessive sweating
- headache
- supraoribital ridge enlargement
- big nose
- big hands and feet
- thickened lips
- macroglossia
- prognathism (protrusion of lower jaw)
- carpal tunnel syndrome
- barrel chest
- kyphosis
