The endocrine System - hypothalamus & pituitary gland Flashcards
decribe the pituitary glands posterior lobe?
contains endings of neurons from the hypothalamus. secretes 2 hormones; ADH & oxytocin
decribe the pituatary glands Anterior lobe?
scretes trophic hormones which regulate other hormones from endocrine glands
what feedback sytems does the hypothalamus & pituitary
short loop feedback - 2nd trophic hormone stimulates reponse
Long loop feedback - 2nd trophic hormone regulates a 3rd hormone which causes a response
where does the pituitary sit?
in the sella turcia of the shenpoid bone
describe tumours of the pituitary and there occurance
10-12% os CNS tumours
called primary adenomas of the anterior gland
benign
secretory or non-secretory
what diagnostic tools are used ?
hormonal diagnosis, radiograph, photograph comparison, clinical examination, ct & mri
what hormone do secretory adenomas produce ?
growth hormone - causes agromegaly
what other diseases do secretory hormones cause?
flow of breast milk, menstral cycle distruption, infertility
what is the treatment used for secretory tumours of the pituitary?
medical therapy - stabilises hormone levels
surgery
what is the sign and symptoms of non-secretory tumours?
optic chiasm compression
what non-secretory tumour treatment is used?
surgery (relieve pressure) - transhenoidal or craniotomy
Radiotherapy - 45GY in 25# or 50Gy in 30# (large & inoperable)
when is RT used for non-secretory tumours
inoperable, Recurrence, extensive tumour invasion of sinuses
what RT technique is used for non-secretory tumours?
4 fields - ant & post oblique , 2 wedged lateral fields (increased dose to temporal lobes
what RT verifications take place
simulation verification, dosimetry, portal imaging,
potential side effects of Rt ?
headache/pressure (steroids - dexamethasone), dizzyness, ear problems, fatigue, hair loss
long term - RT cause hypopituitarism - blindeness & dementia
