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HORMONAL COMMUNICATION - Coggle Diagram
HORMONAL COMMUNICATION
endocrine gland
gland that secretes hormones directly into blood
no ducts
exocrine gland
gland that secretes molecules into a duct that carries the molecules to where they are used
dont release hormones
hormone
act as messengers carrying a signal from endocrine gland to specific target organ/tissue
target tissue
have specific receptor that is complementary to shape of hormone
types of hormone
steroid
lipid soluble
can pass through phospholipid bilayer
enter target cell
have direct effect on DNA (transcription factor)
e.g. sex hormones
peptide
hydrophilc
insoluble in phospholipid membrane
don't enter target cell
bind to specific complementary receptors
e.g
adrenaline
insulin
glucagon
adrenal gland
cortex
essential for life
in response to hormones released from pituitary gland
glucocorticoids
eg. cortisol
blood pressure
metabolism
blood glucose
mineralocorticoids
eg. aldosterone
blood water and salt levels
blood pressure
androgens
eg. oestrogen and testosterone
puberty and menopause
medulla
not essential for life
in response to sympathetic nervous system
adrenaline
fight or flight
heart rate
blood glucose
noradrenaline
stress response
heart rate
narrow blood vessels
steps of insulin secretion
under normal conditions, K+ flow out of cell
when there is a conc gradient, glucose diffuses into cell via facilitated diffusion
glucose is respired and ATP is produced
ATP binds to K+ channels to close them
K+ ions remain in cell
accumulation of K+ increases potential difference of membrane
change in potential difference causes voltage-gated Ca+ channels to open
Ca+ enters cell and bind to vesicles containing insulin, causing them to fuse with membrane
actions of steroid hormones
into cell through membrane
moves into nucleus
binds to receptor protein
transcription factor of DNA to transcribe mRNA
new protein synthesised
actions of peptide hormones
hormone binds to receptor protein on cell surface membrane of target cell
activates enzyme in cell surface membrane
using the enzyme ATP converted into cAMP (second messenger)
cascade of events (effect on cellular function such as glycogen breakdown)