Pituitary and Thyroid Flashcards
what is an endocrine disease
dysfunction of hormone secreting gland
what controls hormone secretion
negative feedback regulation
More hormone secretes less hormone is allowed to be secreted
Switches off secretion to keep blood level at same level
what is the spread of hormones
widespread
multisystem
(unlike nerve)
where is hormone effect determined
where receptors are located
what are the 2 types of endocrine failure
gland failure (primary)
control failure (secondary)
what is primary endocrine faillure
gland failure
gland can make but not being asked to
what is secondary endocrine failure
control failure
gland cannot make
multiple endocrine neoplasia is
Tumour or cancers in one gland are prone to getting different endocrine tumour/cancer in other glands
where is the pituitary gland
in the sella turcica in the skull
what is the function of the pituitary gland
controls many other gland activities
what controls the pituitary gland
hypothalamic control - releasing hormones
Triggers other hormones for other body functions – fire to particular areas particular glands, trigger other pathways
4 anterior pituitary hormones
TSH - Thyroid Stimulating Hormone
ACTH - Adrenocorticotrophic Hormone
Encourage adrenal gland to make cortisol
GH - Growth Hormone
LH, FSH, Prolactin
2 posterior pituitary hormones
ADH - Anti Diuretic Hormone
diabetes insipidus
control of body fluids – concentrate urine
Oxytocin
how is the pituitary gland controlled
Controlled by a mixture of endocrine and neurogenic stimuli
Hypothalamus – allows messenger hormones to pass to pituitary to venous plexus to
Tumour in pituitary gland
- cannot grow in size as in bony space
- Squash gland – so cannot make other hormones
Tends to be multi system disease
what type are pituitary tumours
adenomas
are pituitary tumours benign or malignant mainly
benign
functional adenoma
make hormone as well as being tumour
functional adenoma of prolactin/ACTH above 40 yrs causes
Amenorrhoea-Galctorrhoea syndrome or Cushing’s disease
Producing excess ACTH
Not switched off by normal feedback as tumour don’t respond to normal trigger
functional adenoma of growth hormone above 40 yrs causes
Acromegaly
Growth hormone in excess
Stop growth agree – nose, ears, forehead, fingers, feet
non functional adenoma
squash gland but doesn’t make hormones, space occupying
non functional adenoma effect above 60 yrs
Mass effects - visual field defects, other hormone deficiencies
Gradually spread out of sella turcica
- Pushes on brain above – optic chiasm (eye nerves cross – affect vision, particular peripheral end up with tunnel vision)
- –Take out nasal fields from both eyes so only get lateral field
how to remove a pituitary tumour
Transsphenoidal surgery to remove tumour
- Through nose
- Remove most of tumour and pressure easily
what happens if a child lacks growth hormone
Growth failure in children
reduced height (not dwarf but child like – correct proportions but small)
what happens if an adult lacks growth hormone
increased fat
reduced vitality
not really notice to same extent as fully grown,
causes subtle changes, anabolic, build body up – maintain blood sugar, fat levels