!! 4.5, homeostatis Flashcards
what are hormones
chemicals secreted directly into the bloodstream by various glands (endocrine glands) that make up the endocrine system
how do hormones travel around the body
what do they control
carried by the blood
to a target organ where it produces an effect
control things in organs and cells that need constant adjustment
how do the effects of hormones differ from the nervous system
- hormones are slower
- act for longer
- act in a more general way
where is the pituitary gland
in the brain
middle bottom
give an example of both a nervous and hormonal response
- nervous: really quick e.g pain signals, a message from eyes there’s a lion heading your way ect (hormones too slow to carry that message)
- hormonal: lasts for a long time e.g adrenaline casing flight or fight response keeps your body hyped for action for a long time
(can tell hormonal bc you feel wobbly for a while afterwards)
what does the pituitary gland do
the ‘master gland’
secretes several hormones into the blood in response to the body conditions
these hormones in turn act on other glands to stimulate other hormones to be released to bring about effects
where is blood glucose concentration controlled and monitored
pancreas
what happens if the blood glucose concentration is too high
pancreas produces the hormone insulin which causes glucose to move from the blood into liver and muscle cells
insulin then makes the liver then convert the extra glucose into glycogen and store it
blood glucose levels then reduced
what is type 1 diabetes
what are common treatments
- disorder in which the pancreas fails to produce enough insulin causing uncontrolled high blood glucose levels
- normally treated with insulin injections and limiting foods rich in simple carbohydrates
what is type 2 diabetes
what are common treatments
common risk factor
the body cells no longer respond to insulin produced by the pancreas
commonly treated with a carbohydrate-controlled diet and an exercise regime
obesity is a common risk factor
what happens if the blood glucose concentration is too low
pancreas secretes the hormone glucagon
glucagon makes the liver turn glycagen into glucose
this glucose is then released into the blood by the liver
blood glucose concentration increases
what is negative feedback
used by your automatic control systems
to keep your internal environment stable
how does glucagon interact with insulin in a negative feedback cycle to control blood glucose levels in the body
too high levels of blood glucose, pancreas secretes the hormone insulin
too low levels of blood glucose, pancreas secretes the hormone glucagon
after each, receptors realise levels have retirned to normal and reposnce is turned off
what does blood glucose levels mean
amount of sugar in your body
what is the main reproductive hormone in men
where is it produced
testosterone
produced in the testes
stimulates sperm production
what is the main reproductive hormone in women
where is it produced
oestrogen
produced in the ovaries
name 3 symptoms of both diabetes
tiredness (blood glucose not going into cells)
thirsty (brain realises blood too concentrated)
large volumes of urine
where is glucagon produced
pancreas
what are insulin and glucagon
hormones
what is ovulation
at puberty, eggs begin to mature and one is released approximately every 28 days
what does FSH stand for
what does it do
which stage does it peak
- follicule-stimulating hormone
- causes an egg to mature in one of the ovaries, in a structure called a follicle
- stage 1
which stage of the menstrual cycle does oestrogen peak
stage 2
which stage of the menstrual cycle does LH peak
what does it stimulate
stage 3
stimulates the release of an egg at day 14
which stage of the menstrual cycle does progesterone peak
and where is it produced
stage 4
produced in ovaries by remains of follicle after ovulation
which hormones can be administered to women in a ‘fertility drug’
FSH and LH
what does IVF stand for
In Vitro Fertalisation
which hormones are given to a woman undertaking IVF and why
FSH and LH to stimulate the maturation of several eggs
what are 2 improvements in microscopy techniques enabled development in IVF treatments and higher success rates
specialised micro-tools
time-lapse imaging
cons of IVF treatments
- risk of multiple births, risky for both the mother and the babies
- low success rates
- women can have a physical reactions: vomiting, dehydration, abdomen pain
- emotionally and physically stressful
what can’t some women get preganant
their FSH levels are too low so their eggs don’t mature
Where is FSH produced
the purtuity gland
which other hormone does FSH stimulate the production of
oestrogen
where is LH produced
in the pituitary gland
what does the hormone oestrogen stimulate
causes the uterus lining to grow/ involved in maintaining it
stimulates the release of LH
inhibits the release of FSH
what 2 things does progesterone do
maintains uterus lining during the second half of cycle
inhibits the release of LH and FSH
what happens to a woman’s eggs during IVF
eggs collected from the mother and fertilised in lab using the father’s sperm
the fertilised eggs are developed into embryos
when embryos are tiny balls of cells one or two of the embryos are transferred into the mother’s uterus
where is adrenaline produced
adrenal glands
what effects does the release of adrenaline have on the body
why are these effects released
increases heart rate
boosts delivery of oxygen and glucose to the brain and muscles
these prepare the body for ‘fight or flight’
where is thyroxine produced
thyroid gland
what is the basal metabolic rate
speed at which chemical reactions in your body occur while the body is at rest
what happens when thyroxine levels in the blood get too high
the secretion of TSH (from the pituitary gland) is stopped
reduces the amount of thyroxine released from the thyroid gland
so level of thyroxine in the blood falls back to the normal level
effect of thyroxine on the basal metabolic rate
increases it, making the body’s chemical reactions take place at a faster rate
what are the 2 processes effected by thyroxine
basal metabolic rate
growth and development
3 systems regulated by negative feedback
thyroxine levels in the blood
blood glucose concentration
menstrual cycle
how do specialised micro tools work
used under a microscope
to remove single cells from the embryo for genetic testing
test if it is healthy
what is time-lapse imaging
and how does it work
microscope and camera built into incubator
watches growth of embryos to see which are most likely to result in a successful pregnancy
what happens progesterone levels fall
the uterus lining breaks down
when is adraneline produced
in times of fear or stress
when does your body use negative feedback
when the level of something gets too high or too low
NF used to bring it back to normal
function of the master (pituitary) gland
releases hormones in response to changes of the bodies conditions
detected by the hypothalamus
pro of IVF
Safe and allows people to have a baby that without treatment they could not
Embryos can be screened for genetic diseases
Unused eggs can be used for research or donated to other couples.
