Endocrine systems Flashcards
(17 cards)
describe communication by hormones
many cells in dif parts of body
coordinated, body wide
slow to act but effect persists
name the endocrine glands
hypothalalmus pituitary gland thyroid gland parathyroid gland pancreas adrenal glands GIT glands gonads placenta pineal gland thymus
what are the steroid hormones?
cortisol aldosterone testosterone oestrogen progesterone
what are amino acid derivatives?
non-steroid hormone
amines adrenaline noradrenaline melatonin iodinated amino acids tri-iodo-thyronine (thyroxine) tetra-iodo-thyronine
give examples of short chain peptides
non-steroid hormone
antidiuretic hormone oxytocin melanocyte stimulating hormone somatostatin thyrotropin releasing hormone gonadotropin releasing hormone atrial natriuretic hormone
give examples of long chain peptides
non-steroid hormone
growth hormone prolactin PTH calcitonin adrenocorticotropic hormone insulin glucagon GIT hormones -secretin,CCK, gastrin
what are pro-hormones?
peptide hormones produced in inactive, precursor form, in endoplasmic reticulum becomes prohormone
packaged in Golgi, converted to active hormone, then secreted
what are glycoproteins
non-steroid hormone
process carbohydrate groups attached to the amino acids FSH luteinizing hormone thyroid stimulating hormone chorionic gonadotrophin
what is a paracrine?
hormone like substances which have local effects eg prostaglandins leukotrienes thromboxanes functions include reg blood flow haemostasis mucosal protection inflammation
what are second messengers?
eg cyclic AMP Ca ions
steroid hormones can pass thru the outer cell membrane to reach intra-cellular receptors
what are the basic hormone actions?
synthesis/storage release in response to stimulus transport in blood action on target cell metabolism/excretion
wht affects secretion of PTH?
raised plasma Ca2+ conc. decreases
low plasma Ca2+ conc. increases
what is hypersecretion?
excess secretion
what is hyposecretion?
decreased secretion
what is receptor regulation?
sensitivity of target cell is related to the number of membrane receptors
more receptors=up reg
less receptors=down reg
what is hyper function?
excess production and secretion
up reg of receptors
what is hypo function?
decreased production and secretion
down reg of receptors
receptors non-functioning
