ES. introduction Flashcards
describe endocrine transmission.
- chemical secreted at low conc.
- by a cell or group of cells and sent to all parts of body in blood stream
- hormones act only in cells with correct membrane receptor protein (target cells)
describe features of communication by hormones (humoral)?
- many cells in different parts of body
- coordinated body-wide actions
- slow to act
- effect persists
give examples of endocrine glands?
hypothalamus
pituitary
thyroid
parathyroid
pancreas (islets)
adrenal (super-renal)
GIT endocrine cells
gonads (ovaries and testies)
placenta
pineal gland
thymus
what are the 2 classes of hormones?
steroids and non steroids
subdivide the non-steroid class of hormones?
amino acid derivatives
peptides
glycoproteins
what are steroid hormones based on?
cholesterol ring structure
give some examples of steroid hormones?
cortisol
aldosterone
testosterone (sex)
oestrogen (sex)
progesterone (sex)
what happens if there is no receptor in endocrine transmission?
major problems even death
what is the difference between type 1 and type 2 diabetes?
type 1 = absence of receptor
type 2 = receptor not working
give examples of the amino acid derivatives of non steroid hormones?
adrenaline
noradrenaline
melatonin
give examples of the iodinated amino acids of non steroid hormones?
triiodothyronine
tetraiodothyronine
give examples of peptides short chains of non steroid hormones?
- antidiuretic hormone
- oxytocin
- melanocyte stimulating hormone
- somatostatin
- thyrotropin releasing hormone
- gonadotropin releasing hormone
- atrial natriuretic hormone
give examples of peptide long chains or non steroid hormones?
- growth hormone
- prolactin
- parathyroid hormone
- calcitonin
- adrenocorticotropic hormone
- insulin
- glucagon
- GIT hormones (secretin, CCK, gastrin)
what are pre pro-hormones?
peptide hormones produced in inactive precursor form
where is the pre pro-hormone turned into pro-hormones?
endoplasmic reticulum
how do pro hormones become active hormones?
packed in the Golgi apparatus
after becoming active in the Golgi apparatus where are these hormones secreted?
secreted from vesicles
what are glycoproteins?
protein with attached carb group to amino acids
give examples of glycoproteins?
follicle stimulating hormone
luteinising hormone
thyroid stimulating hormone
chronic gonadotropin
what are local tissue hormones? give examples
hormone - like substances have a local (paracrine effect)
- prostagrandins
- leucotrienes
-thromboxanes
what are the functions of local tissues ?
blood flow regulation
haemostats
mucosal protection (stomach)
inflammation
how do non steroid hormones act?
via second messenger systems within the target cell
what are 2 common second messengers?
cAMP and Ca++
what do steroid hormones do to reach the intracellular receptor?
pas through outer cell
give a brief overview of hormone action?
- synthesis and storage
- release in response to stimulus
- transport in blood
- action on target cells (told of second messenger )
- metabolism and or excretion
what are most hormone Systems regulated by?
negative feedback
what is hyper secretion?
excess secretion
what is hypo secretion?
decreased secretion
what can under or over secretion of hormones lead to?
endocrine disorders
what is upregulation?
more receptors = cell becomes more sensitive to the hormone
- increased affinity
what is down regulation?
less receptors = cell because less sensitive to hormones
- decreased affinity
what is hyper function?
- excess production and secretion
- unpregulation of receptors
- failure to metabolise hormone
what is hypo function?
- decreased production and secretion
- down regulation of receptors
- receptors not functioning
