HPA Flashcards
Formation of the pituitary gland
Fusion of cells from an up growth of ectodermal cells from the primitive pharynx (forms anterior) and down growth of neural tissue from the hypothalamus (forms posterior) - each has different histology and control over glands
What cell types produce what hormone ion the anterior pituitary
TSH - thyrotrophs ACTH - cortiocotrophs GH - somatotrophs LH and FSH - gonadotrophs Prolactin - lactotrophs
Structure of adrenal gland
Adrenal cortex
- zona glomerulosa - mineralcorticoids eg aldosterone
- zona fasciculata - glucocorticoids eg cortisol
- zona reticularis - glucocorticoids and small amounts of androgens
- > adrenal steroids - salt, sugar and sex
Medulla - adrenaline
Actions of cortisol on target cells
Major effects in starved and stressed States and affects substrates by increasing proteolysis, lipolysis and gluconeogenesis
- decrease amino acid and protein syn. And increase proteolysis
- increase hepatic gluconeogenesis and glycogenolysis
- increase Lipolysis in adipose
- peripheral uptake of glucose
Catecholamine synthesis process
Tyrosine to dopamine to noradrenaline to adrenaline
Actions of adrenaline
- cardiovascular - increase output and blood supply to muscle
- CNS - more alert
- carb metab - glycogenolysis in liver and muscle
- lipid metab - lipolysis in adipose
7 clinical signs and symptoms of excess cortisol s
Hyperglycaemia Wasting proximal muscles - thin arms and legs Abdominal fat Purple striae Prone to bacterial infections Back pain and rib collapse Hyoertension
5 clinical effects of too little cortisol
Tiredness, anorexia, weight loss and occasional dizziness
Extreme Muscle weakness
Increased pigmentation on points of friction and scars
Hypotension due to Na and fluid depletion
Hypoglycaemic
Location of pituitary gland
Base of brain suspended from hypothalamus in the recess of the pituitary fossa -
