SB7 Flashcards
what is a hormone
it is a chemical messenger
where is the hormone released to
the blood stream and then target organs
how does the hormone know which organ it should act upon
they are matched to unique receptor cells
what is the collective term for the glands the secrete hormones
the endocrine system
what does the pituitary gland do
it produces many hormones which regulate body conditions
what do the ovaries do
they produce oestrogen
what do the testes do
they produce testosterone
what does the thyroid gland do
they produce thyroxine
what do the adrenal glands do
the produce adrenalin
what does the pancreas do
it produces insulin
what does adrenalin do
it is responsible for the bodies fight or flight response
which two organs does adrenalin affect and what does this do
- it binds to specific receptors in the heart causing the heart muscle to contract more frequently with more force, thus increasing the amount of oxygen being sent to the working muscles
- it binds to receptors in the liver causing the liver the break down its glycogen stores, thus increasing blood glucose levels
how does the level of hormones get controlled
through the use of negative feedback systems
what does thyroxine do
it plays an important role in regulating metabolic rates
what happens when the level of thyroxine is too low
the hypothalamus is stimulated which then causes the release of TRH
what is TRH
thyrotropin releasing hormone
what stimulates the pituitary gland to release TSH
TRH (thyrotropin releasing hormone)
what is TSH
thyroid simulating hormone
what does TSH do
it stimulates the thyroid gland to release thyroxin
what happens on day one of the menstrual cycle
the lining of the uterus begins to break down and is released. it is when menstruation starts
what happens on stage two of the menstrual cycle
from fay 4 to 14 the uterous lining becomes thick and spongy ready for a fertilised egg. the lining is repaired
what happens on stage 3 of the menstrual cycle
an egg develops and is released from the ovary at about day 14
what happens on stage 4 of the menstrual cycle
the lining is maintained for about 14 days , until day 28 and if no fertilised egg has landed on the uterus wall by day 28 the spongy lining starts to break down again and the whole cycle starts again
what is FSH released from
pituitary gland
what is FSH and what is its function
it is the follicle stimulating hormone and it causes a follicle to mature in one of the ovaries and it stimulates oestrogen production
what does oestrogen do and where is it released from
causes the lining of the uterus to thicken and grow. it is released from the ovaries
what does oestrogen do when it is at a high concentration
at a high level of oestrogen will stimulate a LH surge (rapid increase)
what is LH and where is it released from
it is the luteinising hormone and it is released from the pituitary gland
what does LH stimulate at day 14
stimulates ovulation - the follicle ruptures and the egg is released
what else does LH stimulate
it stimulates the remains of the follicle to develop into a structure called corpus luteum - which secretes progesterone
what is progesterone released by and when is this
released by the corpus luteum after ovulation
what two things does progesterone do
- maintains the lining of the uterus
- inhibits the release of FSH and LH
what does a low level of progesterone allow
a low progesterone level allows FSH to increase and then the whole cycle starts again
what happens when both progesterone and oestrogen are at a low level
the uterus lining breaks down
