Adrenal Glands and Pancreas Flashcards
adrenal gland
- > 2 adrenal glands, sits on top of kidneys
- > 2 major regions of adrenal gland, the adrenal cortex (outer region) and the adrenal medulla (inner)
- > adrenal cortex is subdivided into 3 layers (zona)
- zona glomerulosa
- zona fasciculata
- zona reticularis
adrenal hormones
steroid hormones - adrenal cortex
zona glomerulosa - aldosterone
zona fasciculata - cortisol
zona reticularis - androgens
peptide hormones - adrenal medulla
epinephrine
norepinephrine
what are the 3 zona of the adrenal cortex and release what hormone?
zona glomerolusa (outer layer) - aldosterone
zona fasciculata (middle layer) - cortisol
zona reticularis (inner layer) - androgens
adrenal steroid hormone sub-classes
steroid classes (of 5)
- > mineralocorticoids (ex, aldosterone)
- > glucocorticoids (ex, cortisol)
- > androgens (ex, dehyroepiandrosterone (DHEA))
- > progestogens
- > estrogens
how is cortisol released?
- > corticotrophin releasing hormone (CRH) is released and sent to anterior pituitary
- > anterior pituitary releases adrenocorticotropic hormone (ACTH) which stimulates the adrenal glands
- > adrenal cortex is stimulated and cortisol is released by the zona fasiculata into the blood
cortisol effects
- > helps cope with stress
- > catabolic: breakdown of larger macromolecules
- > adipose - lipolysis: breakdown of lipids - triglyceride - glycerolfatty acids
- > muscles - protein catabolism - proteins - amino acids + effects on bone
- > immune system - immune supression
- > gluconeo genesis - glucose - impacts blood glucose
what does aldosterone do?
aldosterone - balances sodium and potassium in blood
what does androgens do?
androgens - sex hormones (mostly for males)
gluconeogenesis
- > gluconeogensis in liver
- > protein degration - muscle
- > fat breakdown (lipolysis) - adipose
- > glycogen, proteins and lipids are broken down to create glucose in the liver
cushing’s disease: hypersecretion
- > hyperglycemia
- > muscle wasting (atrophy) and weakness
- > thinning skin with tearing (stretch marks)
- > stunted growth and osteoporosis
- > adipose redistribution & increased infections
- > easily bruses
- > abdominal weight gain
adrenal medulla
epinephrine: hydrophilic amine (catecholamine)
trigger for release: sympathetic branch of autonomic nervous system
target tissue effects:
- increases gluconeogenesis
- increases heart rate
- relaxes lung airways
- increases blood pressure by constricting blood vessels
pancreas
endocrine cell location: Islet of Langerhans
Alpha (a) cells: glucagon
Beta (B) cells: insulin
glucagon
alpha cell
stimulus - hypoglycemia (low blood glucose)
effects - target cells released store glucose into blood from cells
antagonistic (opposite) relationship to insulin
insulin
beta cells
stimulus - hyperglycemia (high blood glucose)
effects - act on receptors of body cells to store glucose into the cells from blood
antagonisitic (opposite) relationship with glucagon
