14.1 Hormonal communication Flashcards
(22 cards)
What is a hormone
Chemical messenger
transported by bloodstream
secreted by gland
What’s an endocrine gland
A gland specialised to secrete hormones directly into the blood stream
What’s the function of the pineal gland
produces melatonin
affects reproductive development & daily cycles
What’s the function of the thymus gland
produces thymosin
promoted production & maturation of white blood cells
What’s the function of the adrenal gland
produces adrenaline
increases heart rate, breathing rate & blood glucose level
What hormones are released by the ovaries
oestrogen - develops lining
progesterone - maintains lining
What hormones are produced by the pituitary gland
Growth hormone ADH and gonadotrophins
What’s the function of the thyroid gland
produces thyroxine
controls rate of metabolism & rate of glucose respiration
What’s a steroid hormones
Hormone which is lipid-soluble
so can pass through membranes
What’s a non steroid hormone
Hormone which is non-lipid soluble/hydrophilic
cannot pass through membranes
How do steroid hormones function
steroid hormone passes through lipid component of plasma membrane
binds to specific receptors (either in cytoplasm or nucleus)
hormone-receptor complex acts as transcription factor
inhibits/facilitates transcription of specific gene
How do non steriod hormones function
cannot pass through plasma membrane since hydrophilic & non-lipid soluble
bind to specific receptors on plasma membrane (non inside cell)
triggers cascade of reactions, mediated by second messengers
Compare the way in which hormonal and nervous systems function
HORMONAL:
uses chemical hormones
travel in bloodstream
slow to bring about response/slow transmission
responses are long-lasting
response is widespread
effect may be irreversible
travel to all parts of body, but only target organs respond
NERVOUS:
uses electrical impulses & chemical neurotransmitter
travels by neurones
fast to bring about response/fast transmission
response is short-lived
response is localised
effects usually reversible
travels to specific parts of the body
What’s the structure of the adrenal gland
ADRENAL CORTEX - produces vital hormones, aldosterone + cortisol
ADRENAL MEDULLA - produces non-essential hormones, adrenaline
What are the three main types of hormones released by the adrenal cortex
Glucocorticoids
Mineralocorticoids
Androgens
What is the role of glucocorticoids
These include cortisol which helps regulate metabolism by controlling How fast the body converts fats proteins and carbs to energy also helps regulate bp and cardiovascular function
Anotherglucocorticoid hormone is corticosterone which works with cortisol the regulate immune response
The release of these hormones is controlled by the hypothalamus
What’s the role of mineralcorticoids
The main one produced is aldosterone which helps control blood pressure by maintaining salt and water concentration
What’s the role or androgens
Small amounts of sex hormones are released
What 2 hormones are released by the adrenal medulla
Adrenaline and noradrenaline
Release when the sympathetic nervous system is stimulated
What’s the role or androgens
Small amounts of sex hormones are released
What’s the role of adrenaline
It increases the heart rate sending blood quickly to the muscles and brain it also rapidly raises blood glucose conc by converting glycogen to glucose in the liver
What’s the role of noradrenaline
This hormone works with adrenaline in response to stress producing effects eg raised heart beat widening pupils widening bronchi and narrowing blood vessels to non essential organs
