The pituitary gland and its disorders Flashcards
(21 cards)
What are the three layers of endocrine system?
End organ = primary
Pituitary = secondary
Hypothalamus = tertiary
Which cranial nerve is most likely to be affected by a pituitary tumour?
6th
All of the other neves lie along the lateral wall of cavernous sinus
Sixth nerve lies medially
Where does the pituitary lie below?
Sella turcica
Another name for anterior lobe?
Adenohypophysis
(derived from invagination of the roof of the embryonic oropharynx)
Another name for posterior pituitary?
neurohypophysis
What forms the pituitary stalk?
notochordral projection
What type of blood supply does the pituitary have?
Dual blood supply
(long and short pituitary arteries
hypophyseal portal circulation)
Symptoms of GH/IGF-1 excess?
Acral enlargement
Increased skin thickness
Sweating
Metabolic chnages
Impaired glucose tolerance
Diabetes mellitus
How is prolactin inhibited ?
Tonic release of Dopamine inhibits PRL release
How is prolactin released?
Upon mechanical stimulation, signal is sent to stop dopamine production
large surge in prolactin
Is prolactin positive or negative feedback?
Positive
What drugs can interfere with DA and PRL?
Antiemetics
anti seizure drugs
OCP/HRT
What can be used to treat PRL excess?
Dopamine agonists
What % of pituitary tumours are non functioning?
30%
No syndrome of hormone excess
Order of loss of pituitary function?
- Growth
- Sex
- Metabolism
- Survival
- Stalk compression
Causes of pituitary faliure?
- Tumour
- Trauma
- Infection
- Inflammation
- Iatrogenic
ADH defiency?
Diabetes insipidus
Why are normal thyroid levels needed to express ADH?
THyroid hormone controls ADH receptors in kidney
What is SIADH
syndrome of inappropriate ADH
Too much ADH
How is SIADH treated?
- fluid restriction
- demeclocyline
- ADH antagonist
Test for diabetes insipidus?
water deprivation test
