Pituitary gland Flashcards
(32 cards)
What is the pituitary gland?
small, pea-sized gland located at the base of the brain, responsible for secreting several hormones that regulate various bodily functions.
What are the two main parts of the pituitary gland?
The pituitary gland is divided into two main parts: the anterior pituitary (adenohypophysis) and the posterior pituitary (neurohypophysis).
What hormones are secreted by the anterior pituitary?
growth hormone GH
prolactin
follicle-stimulating hormone
luteinizing hormone
adrenocorticotropic hormone ACTH
thyroid-stimulating hormone TSH
What hormones are secreted by the posterior pituitary?
oxytocin and vasopressin (also known as antidiuretic hormone).
What is the hypothalamus-pituitary axis?
feedback loop that controls the release of hormones from the pituitary gland. The hypothalamus produces hormones that stimulate or inhibit the release of pituitary hormones.
function of growth hormone?
promotes growth and development of bone and muscle, and helps regulate metabolism and body composition.
function of prolactin?
stimulates milk production in lactating females and may also have a role in reproductive function and behavior.
What is the function of adrenocorticotropic hormone (ACTH)?
ACTH stimulates the adrenal gland to produce cortisol, which helps regulate metabolism and the body’s response to stress.
What is the function of thyroid-stimulating hormone (TSH)?
TSH stimulates the thyroid gland to produce thyroid hormones, which help regulate metabolism, growth, and development.
What is the function of oxytocin?
Oxytocin plays a role in social bonding and attachment, and stimulates contractions of the uterus during childbirth and milk ejection during breastfeeding.
What is the function of vasopressin (antidiuretic hormone)? ADH
Vasopressin regulates water balance in the body by promoting water reabsorption in the kidneys, and also plays a role in regulating blood pressure and social behavior.
acromegaly
disorder caused by excess production of growth hormone in adulthood
acromegaly symptoms
enlargement of the hands and feet
protruding jaw and forehead
deepening of the voice
excessive sweating
spade like hands
wide feet
thick lips and tongue
carpal tunnel
prolactinoma
benign tumor of the pituitary gland that produces excessive amounts of prolactin, leading to abnormal milk production, menstrual irregularities, and decreased sex drive in women and men.
Cushing’s disease
disorder caused by excessive production of cortisol by the adrenal glands, due to a pituitary tumour that produces excess adrenocorticotropic hormone (ACTH).
cushings disease symptoms
weight gain
moon face
buffalo hump
high blood pressure
menstrual irregularities
increased risk of infections and fractures
easy bruising
stretch marks
central obesity
hirsutism
hyperpigmentation
acromegaly complications
headache
chiasmal compression
diabetes
sleep apnoea
colon caner
osteoarthritis
acromegaly investigations
clinical features
IGF1 elevated levels
GH
MRI and CT to locate tumour
OGTT
acromegaly is caused by
benign tumour of pituitary gland or tumours in other parts of body that produce GHRH
management of acromegaly
remove the tumour primary choice
somatostatin analogues SSA or growth hormone receptor antagonists GHRA
radiotherapy in some cases
monitor GH and IGF1 levels
what is IGF1
Insulin-like Growth Factor 1, which is a hormone that is mainly produced by the liver in response to growth hormone (GH) stimulation
promotes cell growth and proliferation, particularly in bone and muscle tissues. IGF1 also plays a role in regulating metabolism, blood sugar levels, and insulin sensitivity.
key regulators of growth and development in the body
cushings disease causes
pituitary tumour
cushings disease investigations
elevated levels of cortisol and ACTH in blood-
low dose dexamethasone :
low cortisol- normal, high/ normal cortisol- cushings syndrome
then high dose:
low cortisol- cushings disease, high/normal- ectopic or adrenal (low ACTH)
then CRH test
management cushings syndrome
pituitary surgery through nose- transphenoidal
surgical removal of adrenal tumour
surgical removal of ectopic ACTH tumour
or remove adrenal glands and give replacement steroid hormones
