Hormonal co-ordination in animals TOPIC 5 Flashcards
what is the endocrine system made up of
glands that secrete hormones directly into the bloodstream
What are hormones
chemicas which control the way in which parts of the body work and are transported to their target organs in the bloodstream
what are the hormones in this topic
- insulin = pancreas
- adrenaline = adrenal glands
- FSH = pituitary gland
- LH = pituitary gland
- testosterone = testes
- oestrogen = ovaries
- thyroxin = thyroid glands
- ADH = pituitary gland
why is glucose important
for respiration
what are the two hormones which are involved in glucose regulation
- insulin
- glucagon
where are insulin and glucagon released from and where does it go
the pancreas to the liver
when is insulin released
when the glucose level is too high
what is the effect of insulin on the liver
liver converts glucose into glycogen which is stored in the liver and skeletal muslces so the glucose is removed from the blood
when is glucagon released
when the glucose levels are too low
what is the effect of glucagon on the liver
liver converts glycogen to glucose so glucose is released into the blood
what mechanism keeps blood glucose levels constant
negative feedback
describe negative feedback
- when the internal factor rises above the normal level, the body lowers the factor
- when the internal factor falls below the normal level, the body raises the factor
what happens if your pancreas doesn’t make enough insulin
you get type 1 diabetes
what is diabetes
when you don’t produce enough insulin so you blood glucose level gets very high and you excrete glucose in your urine
what are the impacts of diabetes
- feel very thirsty
- lack energy & feel tired
- lose weight
when does type two diabetes get more common
- people get older
- people get obese
- lacking exercise
what may well-managed diabetes cause problems with even still
the cirulatory system
- kidneys
- eyesight
How do you treat type 1 diabetes
you have to take replacement insulin before meals as an injection
what must you bear in mind if you have type 1 diabetes
- carbohydrate levels you eat
- regualr meals
- exercise
how is water taken into the body
through ingesting food and drink
how does water leave the body
- via the lungs in exhalation
- from the skin in sweat
what is removed by the kidneys
- excess water
- excess ions
- urea
what do the kidneys do with glucose
they reabsorb all the glucose to return it to the blood plasma
what is the function fo the kidneys
to produce urine by filtration and selective reabsorbtion of useful substances suh as glucose, some ions and water
what happens if the bdy cells gain or lose too much water
they do not function properly
how is the water concerntration maintained at a constant level
by nnegative feedback involving the hormone ADH
where is the ADH secreted from
pituitary gland
why may the kidneys fail
- can be damaged or destroyed by infection
- fail due to genetic problems
- damaged due to an accident
what cna untreated failure to both kidneys leadd to
death
how can kidney failure be treated
- dialysis = the function is carried out artificially
- kidney transplant = failed replaced with healthy one
what happens in a dialysis machine
the kidney machine consists of a partially permeable membrane that seperates the arterial blood from a dialysis fluid. The blood and dialysis fluid are constantly circulated through the machine.
what are the tiny tubes in the kidney called
nephrons
what is the process in which removes the amino groupd from amino acids
deamination
where does deamination occur
the liver
what does deamination form
ammonia, which is then immediately converted into urea
where is urine stored in the body
the bladder
if you are dehydrated what is the concerntration of your urea in the urine like
highly concerntrated
what happens if the water content is too high in the plasma
less ADH is secreted
- decreasing the permeablity of the kidney tubules
- less water is reabsorbed
- greater volume of urine is produced
what cautions do people on dialysis have to take
- control their protein intake = urea levels low
- control salt intake = cannot remove excess mineral ions
- may feel tired or unwell before sessions
- regular long sessions
decribe the process of dialysis
- blood leaves arm through artery
- blood passed through a pump (maintain pressure)
- anticoagulants addded to prevent clotting
- thinned blood enters machine
- blood passes over dialysis membrane
- fluid flows in opposite direction to blood
- waste materials removed (diffuse down gradient)
- glucose not removed
- filtered blood flows through bubble trap
- filtered blood returned to vein
what is the main problem with a donor kidney
kidney has different antigens on cell sruface to the recipients - antibodies will attack the antigens on the donor organ = rejection and destruction
how do you reduce the risk of rejection of a donor kidney
- do a tissue match so the anigens are similar
- take immunosuppresant drugs for the rest of life
what is the disadvantage of immunosuppresants
they revent the patiens from dealing effectively wiht infectious diseases, will havae to take great care when falling ill
what are the advantages of a transplant
- can lead a normal life with no regular trips to the hospital
- long term cost is low
- good success rate
what are the disadvantages of a transplant
- take immunosuppresants for life
- repeated after 10 years
- shortage in donors
- tissue matching is essencial
- must be transplanted within 12 hours
- irradiation of bone marror must occur
what are the hormones in the mentrual cycle
- FSH = pituitary
- Oestrogen = ovaries
- LH = pituitary
- Progesterone = ovaries
what is the average length of the mentrual cycle
28days
what does FSH do
- matures the eggs in the ovaries
- stimulates the production of oestrogen
what does oestrogen do
- stimulates the lining of the urterus to thivken adter menstruation
- inhibit the production of FSH
- sitmulate the production of LH
what does LH do
- stimulates the release of a mature egg from the ovary
- levels will fall after ovulation
when is progesterone secreted
by the empty eggg follicle in the ovary after ovulation
what does prgesterone do
- helps maintain a preganancy is egg fertilised
- inhibits both FSH and LH
- maintains lining of the uterus so it is ready to recieve a developing embryo
how many stages of the mentrual cycle are there
4 : day1, 4, 14, 28
desribe the mentrual cycle
- day 1 = uterus lining breaks down
- day 4 = lining builds up again
- day 14 = an egg is released (lasts 3 days)
- day 28 = lining stays thick awaiting fertilised egg, if not cycle repeats
when is the folicular phase of the mentural cycle
day 1 - 14(ovulation)
when is the iuteal phase
day 14 - 28 (awaiting ferilisation)
what are the oral cotraception methods
- oestrogen pill
- progesterone pill
- combined pill
what are the tempory methods of contraception
- patches
- injection
- implant
what are the barrier methods of contraception
- condoms
- femidoms
- diaphram
what are the intrauterine methods of contraception
- progesterone IUDs
- copper IUDs
what are natural methods of contraception
- rythem method
- adstainence
what are the surgical methods of contraception
- tubal ligation
- vasectromy
what is a vasectomy
the cutting of the sperm ducts to lrevent ejacualation of sperm
what are the types of fertility treatments
- hormone treatment
- in vitro fertilitsation
how does a hormone treatment work
FSH and LH are given to women with low fertality to stimulate ovulation
what are the benefits and disadvantages of the hormone treatments for infertality
+increases the chnace of pregnancy
-not always successful = expensive
-lead to women producing more than one egg at ovulation = risk of multiple births
how does in vitro fertillisation work
- woman given FSH & LH to produce mature eggs
- eggs collected from ovary
- sperm collected from male on same day
- sperm injected into mature egg in lab
- embryos develop and transferred into uterus
when does in vitro fertillisation take place
- woman has blocked fallopian tubes
- male sperm count or motility is low
what are the benefits and disadvantages of in vitro fertillisation
+inreases chance of infertile cpupble giving birth
-multiple births can occur
-success rate is very low (26%)
-stressful procedure
-can experience side effects
where is thyroxine produced
the thyroid gland
what does thyroxine do
control cell metabolism
what controls thyroxine levels
negative feedback
describe the negative feedback for thyroxine
as levels of thyroxine increase in the bloodstream TSH is inhibited
what does TSH do
stimulate the production of thyroxine by the thyroid gland
where is adrenaline produced
the adrenal glands
what controls the levels of adrenaline
positive feedback = further enhanced changes are further changed in the same direction
what are the effects of adrenaline
- heart rate and breathing rate increases
- stored glycogen converted to glucose for respiration
- mental awareness increased
- blood diverted away from digestive system to the muscles in limbs
what does adrenaline do
prepares body for fight or flight by boosting the delivery of oxygen and glucose to brain and muscles
does adrenaline involve negative feedback
no
