during times of fear and stress the adrenal gland produces a hormone called adrenaline which is released in the blood
what is the main effects of adrenaline?
to increase the heart rate - the heart is beating more faster so more O2 and C6H12O6 are delivered in the blood to brain and muscles. Both O2 and C6H12O6 is needed for aerobic respiration = prepares body for fight or flight
which hormone does the thyroid gland release?
thyroxine
2 main effects of thyroxine:
thyroxine stimulates the body's metabolic rate = body's chemical reactions take place much faster
important for growth and development
what is metabolism?
sum of all the reactions in a cell or body
what happens when thyroxine level falls?
the PG releases the hormone TSH into bloodstream
TSH triggers the TG to release more thyroxine into blood
the increased level of thyroxine is detected by brain - prevents the PG from releasing TSH
a TSH level falls the thyroid gland releases less thyroxine
if the level of thyroxine falls, events are triggered which causes the level of thyroxine to increase
