Hypopituitarism Flashcards
(56 cards)
What is the function of the hypothalamus in the
endocrine system?
Regulating the release of hormones from the pituitary gland - control other endocrine glands
What is the difference between primary and
secondary hypopituitarism?
1° Hypopit - dysfunction of pituitary gland
2° Hypopit - dysfunction of the hypothalamus
What is Sheehan’s syndrome?
Condition where pituitary gland is damaged due to severe bleeding in childbirth
What is the function of growth hormone?
aka somatotrophin
stimulates growth and cell reproduction
What is the function of TSH?
aka thyrotrophin
stimulates thyroid to produce hormones
What is the function of LH and
FSH?
regulates the reproductive system
What is the function of ACTH?
aka corticotrophin
stimulates release of cortisol, hormone that helps with stress
What is the hypothalamo-pituitary portal system?
Specialised network of blood vessels connecting hypothalamus and pituitary, allows transport of hormones
What is the function of the
hypothalamo-pituitary portal system?
Stimulatory/ inhibitory factors travel in portal circulation to anterior pituitary.
Anterior pituitary hormones
GH, ACTH, LH, TSH, FSH, Prolactin
What are the causes of
anterior pituitary failure?
1° disease - gland itself fails
2° disease - no signals from hypothalamus or anterior pituitary
What are the clinical features
of primary hypothyroidism?
T3 and T4 levels fall,
while TSH levels increase.
What are the clinical features
of secondary hypothyroidism?
TSH levels fall due to
pituitary tumor damaging thyrotrophs, leading to a
decrease in T3 and T4 levels.
Treated with levothyroxine, dose adj to fT4
Primary hypoadrenalism
destruction of adrenal cortex (e.g. autoimmune)
cortisol falls, ACTH rises
Secondary hypoadrenalism
pituitary tumour damaging corticotrophs
Can’t make ACTH
ACTH falls, cortisol falls
treated with glucocorticoid replacement (prednisolone/hydrocortisone)
Primary hypogonadism
destruction of testes (mumps) or ovaries (chemotherapy)
Testosterone/oestrogen fall, LH & FSH increase (we don’t measure GnRH but that
would also be high)
Secondary hypogonadism
pituitary tumour damaging gonadotrophs
LH/FSH fall, Testosterone/oestrogen fall
management depends on whether restoration of fertility is needed
What are the causes of congenital hypopituitarism?
usually due to
mutations of transcription factor genes needed for
normal anterior pituitary development.
What are the 8 acquired causes of hypopituitarism?
TTRIIPSS: tumour, trauma, radiotherapy, infection, inflammation (hypophysitis), pituitary apoplexy, surgery, sheehan’s syndrome
What are the clinical features of congenital
hypopituitarism?
short stature and hypoplastic
(underdeveloped) anterior pituitary gland on MRI.
What are the clinical features of acquired
hypopituitarism?
may include fatigue,
weight loss, decreased libido, infertility, menstrual
irregularities, and cold intolerance.
What is panhypopituitarism?
Total loss of anterior and posterior pituitary function
What may cause posterior pituitary dysfunction?
Certain processes, especially inflammation (hypophysitis) or surgery.
What is radiotherapy-induced
hypopituitarism?
pituitary and hypothalamus are both sensitive to radiation.
prod pituitary/CNS tumour
The higher the radiotherapy dose (Gy), the higher the risk of HPA axis damage
GH and gonadotrophins most sensitive
Risk persists up to 10yrs post radiotherapy .: annual assessment needed
