hormones and kidney Flashcards
(91 cards)
1
Q
how does your body warm up
A
1) your temperature receptors detect that core body temperature is too high
2) the thermoregulatory centre acts as a coordination centre, it receives information from the temperature receptors and triggers the effectors automatically
3) the effectors e.g sweat glands produce a response and counteract the change
2
Q
how does your body cool down
A
1) temperature receptors detect that core body temperature is too low
2) the thermoregulatory centre acts as a coordination centre, it receives information from the temperature receptors and triggers the effectors automatically
3) effectors e.g muscles produce a response and counteract the change
3
Q
how do your effectors produce a more sensitive response to the body’s temperature
A
- some effects work antagonistically and will work at the same time to achieve a very precise temperature, this mechanism allows a more sensitve response
4
Q
how does the body keep the core body temp constant
A
by balancing the energy gained and lost
5
Q
where is the thermoregulatory centre found
A
in the brain
6
Q
what does the thermoregulatory centre contain
A
receptors that are sensitive to the temperature of the blood flowing through the brain
7
Q
what does the thermoregulatory centre do
A
- the thermoregulatory centre acts as a coordination centre, it receives information from the temperature receptors of the brain and skin giving information about the body temperature
8
Q
what happens to your body when your too hot
A
1) sweat is produced by the sweat glands and evaporates from the skin, this transfers energy to the environment
2) the blood vessels supplying the skin dilate so more blood flows to the surface of the skin, this is called vasodilation, and this helps transfer energy from the skin to the environment
9
Q
what happens to the body when you are cold
A
1) hairs stand up to trap an insulating layer of air
2) no sweat is produced
3) blood vessels supplying skin capillaries constrict to close off the skins blood supply, this is called vasoconstriction
4) when youre cold you shiver by muscles contracting automatically, this needs respiration which transfers some energy to warm up the body
10
Q
what are hormones
A
chemical molecules released directly into the blood
11
Q
what do hormones do
A
- control things in organs and cells that need constant adjustment
- are carried in the blood to other parts of the body and only affect particular cells in target organs
12
Q
where are hormones produced
A
in glands called endocrine glands
13
Q
examples of endocrine glands that make up the endocrine system
A
- pituitary gland - this produces many hormones that regulate body conditions, these hormones also affect other glands causing them to produce hormones that bring about a change (also known as master gland)
- thyroid - this produces thyroxine which involves regulating things such as the rate of metabolism, heart rate and temp
- adrenal gland - produces adrenaline which is used to prepare the body for a fight or flight response
- ovaries - produce oestrogen - which is involved in the menstrual cycle
- pancreas - produces insulin which is used to regulate the blood glucose level
14
Q
examples of endocrine glands that make up the endocrine system
A
- pituitary gland - this produces many hormones that regulate body conditions, these hormones also affect other glands causing them to produce hormones that bring about a change (also known as master gland)
- thyroid - this produces thyroxine which involves regulating things such as the rate of metabolism, heart rate and temp
- adrenal gland - produces adrenaline which is used to prepare the body for a fight or flight response
- ovaries - produce oestrogen - which is involved in the menstrual cycle
- pancreas - produces insulin which is used to regulate the blood glucose level
- testes - produces testosterone which controls puberty and sperm production in males
15
Q
difference between hormones and nerves
A
HORMONES
- slow action
- act for a long time
- act in a more general way
NERVES
- very fast action
- acts for a short time
- acts on a very precise area
16
Q
what happens when your blood glucose is too high
A
1) insulin is secreted by the pancreas
2) insulin travels in the bloodstream all around the body and triggers body cells to take up glucose from the blood, liver and muscle cells to convert the glucose into glycogen to store excess glucose
3) as the glucose has now been taken out of the blood and stored the concentration of glucose in the blood returns to its normal level
17
Q
what happens when the blood glucose level is too low
A
1) the pancreas releases the hormone glucagon into the bloodstream
2) glucagon triggers liver cells to convert glycogen stores back to glucose
3) the glucose is then released into the blood
4) this causes the blood glucose concentration to return back to normal
18
Q
what is diabetes
A
a condition that affects your ability to control your blood sugar level
19
Q
what is type 1 diabetes
A
- this is where the pancreas produce little or no insulin
- this causes the blood glucose concentration to rises and stay at a high level as the pancreas does not produce a sufficient amount of insulin
20
Q
how do you treat type 1 diabetes
A
- they have insulin therapy - this is involves them being injected with insulin throughout the day, especially at meal times to make sure that glucose is removed from the blood quickly once the food has been digested, stopping the level from getting to high - the amount of insulin injected depends on the persons diet and how active they are
- they are also encouraged to limit their intake of food rich in simple carbohydrates - which causes glucose levels to rise rapidly and to do regular exercise - which removes excess glucose from blood
21
Q
symptoms of type 1 diabetes
A
- you urinate a lot as the kidney has to secrete glucose into the urine making you more thirsty
- feel very fatigue and tired as not enough glucose is sent to the cells
- you start to lose weight as the body starts to break down fats and proteins as fuel
22
Q
what is type 2 diabetes
A
when a person becomes resistant to their own insulin causing the blood glucose level to rise too high
23
Q
how do you treat type 2 diabetes
A
- having a carbohydrate controlled diet to stop the blood glucose concentration from rising to high
- regular exercise
24
Q
what causes type 2 diabetes
A
- genetics
- obesity
25
what does the kidney do
it makes urine by taking waste products out of the blood to filter it
useful substances passed through the kidney are absorbed back into the blood from the kidney through the process of selective reabsorption
26
what substances are removed from the body in urine
- urea
- ions
- water
27
why does urea need to be removed from the blood
- proteins cant be stored by the body so any excess amino acids are converted into fats and carbohydrates which can be stored, this occurs in the liver and is called deamination
- ammonia is a waste product in deamination, which is toxic so it's converted to urea in the liver, urea is then transported to the kidneys where it's filtered out of the blood and excreted from the body in urine
28
why does ions need to removed from the blood
- ions are taken into the body in food and then absorbed into the blood
- if the ion content is wrong this could disrupt the balance between ions and water, meaning too much or too little water is drawn into the cell by osmosis, having the wrong amount of water can damage cells or mean they don't work as well
- some ions are lost in sweat, however this amount is not regulated so the right balance of ions in the body must be maintained by the kidneys.
- the right amount of ions is reabsorbed into the blood after filtration and the rest is removed from the body into the urine
29
why does water need to be removed from the blood
- we lose water from the skin in sweat and from the lungs when breathing out this means that water has to be constantly balanced
- we cant control how much water we lose so the amount of water is balanced by the amount we consume and the amount removed by the kidneys in urine
30
what is the concentration of urine controlled by
a hormone called anti-diuretic hormone, ADH
31
where is ADH made
in the pituitary gland
32
what happens if the water content too high
1) receptors in the brain detect that the blood plasma is too dilute
2) the coordination centre in the brain receives this info and coordinates a response
3) the pituitary gland releases less ADH so less water is reabsorbed from the kidney tubules, so you produce the volume or dilute urine and the water concentration returns back to normal
33
what happens if the water content is low
1) receptors in the brain detect that the blood plasma is too concentrated
2) the coordination centre in the brain receives this info and coordinates a response
3) the pituitary gland releases lots of ADH so more water is reabsorbed from the kidney tubules, so you produce a small volume of concentrated urine and the water concentration returns back to normal
34
what is negative feedback
an automatic control systems to keep your internal environment stable
35
how does negative feedback work
1) receptor detects a stimulus
2) the coordination centre receives and processes the info and then organises a response
3) effector produces a response that counteracts the change and restores the optimum level
36
what happens if your kidneys dont work properly
- waste substances start to build up in the blood and you lose your ability to control the levels and ions in the body and this eventually leads to death
37
how is kidney failure treated
- with dialysis machines
- kidney transplants
38
how do dialysis machines work
1) the persons blood flows between partially permeable membranes surrounded by dialysis fluid, its permeable to ions and waste substances but not big molecules
2) the dialysis fluid has the same concentration of dissolved ions and glucose as healthy blood, this means that useful dissolved ions and glucose wont be lost from the blood during dialysis
3) only waste substances and excess water and ions diffuse across the barrier
39
cons of dialysis machines
- patients with kidney failure have to have 3 sessions a week
- sessions takes 3-4 hours
- its expensive
40
pros of dialysis
- can provide patients with an alternative until they find a donor organ
41
cons of kidney transplants
- donor kidney can be rejected but this can be prevented with immunosuppressant
- long waiting lists
- can cause blood clots
- can cause infections
42
pros of kidney transplants
- cheaper
- free from restrictions
43
what happens during puberty
- your body starts releasing sex hormones that trigger off secondary sexual characteristics and cause eggs to mature in women
44
what happens to men during puberty
caused by rising levels of testosterone
- growth spurt
- pubic hair
- testes grow and become more active producing sperm
- larynx gets bigger and voice breaks
45
what happen to females during puberty
- caused by the rising levels of oestrogen
- breast development
- growth spurt
- skin darkens
- growth of hair underarms and pubic hair
- menstruation begins
46
stages in menstrual cycle
stage 1 - day 1 menstruation starts, the uterus lining breaks down for 4 days
stage 2 - the uterus lining builds up again from day 4 to day 14 into a thick spongy layer full of blood vessels ready to receive a fertilised egg
stage 3 - an egg develops and is released from the ovary at day 14 - this is called ovulation
stage 4 - the was is then maintained for 14 days until day 28, if no fertilised egg has landed on the uterus wall by day 28 the spongy lining starts to break down and the cycle restarts
47
what hormones is the menstrual cycle controlled by
- FSH (follicle stimulating hormone) - produced in the pituitary gland - causes the egg to mature in the ovaries in a structure called a follicle and stimulates the ovaries to produce oestrogen
- Oestrogen - produced in the ovaries - causes the lining of the uterus to grow and stimulates the release of LH and inhibits the release of FSH
- LH (luteinising hormone) - produced by the pituitary gland and stimulates ovulation
- Progesterone - produced in the ovaries - maintains the lining of the uterus during the second half of the cycle (usually if the women is pregnant) and when the level of progesterone falls the uterus lining breaks down - also inhibits the release of LH and FSH
48
how does menstrual cycle works with hormones
1) FSH is released by the pituitary gland, then travels in the blood to the ovaries this matures the eggs
2) FSH then stimulates the ovaries to produce oestrogen causing the uterus lining to become developed
3) the oestrogen then inhibits the release of FSH and stimulates the release of LH
4) The LH is then produced in the pituitary gland and stimulates ovulation
5) if the women is pregnant ovaries then release progesterone which maintains the uterus lining and inhibits FSH and LH to prevent any more eggs from maturing or being released
49
what methods can reduce fertility
- hormone-based contraception
- barrier methods
- sterilisation
- abstinence
50
examples of steralisation
- vasectomy - where they cut and tie their sperm duct, preventing the sperm from entering the semen
- women can get their oviduct cut and tied and this prevents the egg from entering the uterus and the sperm entering the egg
51
what hormonal methods can reduce fertility
- oestrogen pills
- progesterone only pills
- contraceptive pills , patch , injection
- IUD
52
how do oestrogen pills reduce fertility
- the oestrogen inhibits the production of FSH and after a while egg development and production stop preventing pregnancy
53
how does progesterone only pills reduce fertility
- it stimulates the production of thick mucus which prevents the sperm from entering and reaching the egg
-
54
how does the contraceptive pill prevent pregnancy
- this contains a mix of oestrogen and progesterone which inhibits the production of FSH, this affects the ovaries by stopping the maturing of an egg preventing pregnancy
- it also stimulates the production of thick mucus which prevents the sperm from entering and reaching the egg
side effects
- high blood pressure, breast cancer and thrombosis
does not protect against STD
55
how does the contraceptive patch reduce fertility
- contains a mix of oestrogen and progesterone, which your skin absorbs into the bloodstream this inhibits the production of FSH, which affects the ovaries by stopping the maturing of an egg preventing pregnancy
- it also stimulates the production of thick mucus which prevents the sperm from entering and reaching the egg
BUT
has to be replaced every week
56
how does contraceptive injections reduce fertility
- it contains progesterone (works the same as the progesterone-only pill)
BUT
doses only last 2-3 months
57
how does contraceptive implant reduce fertility
- its inserted under the skin slowly releasing progesterone
- this lasts 3 years
58
how does IUD reduce fertility
- its a t shaped device that is inserted into the uterus to kill sperm and prevent implantation of a fertilised egg
two types:
- plastic IUD - releases progesterone
- copper IUD- prevents from sperm surviving in the uterus
59
what barriers reduce fertility
- condoms - worn over the penis during intercourse and this prevents the sperm from entering the vagina also prevents STDs
- diaphragm - a shallow plastic cup that fits over the cervix to form a barrier but has to be used with spermicide
- spermicide - dissolves and kills sperm
60
how does abstinence reduce fertility
- this is when you dont have sex at all or during ovulation
61
how can you increase fertility
- hormone tablets
- IVF
62
How can hormone tablets increase fertlilty
- when women have levels of FSH that are too low to cause their eggs to mature, it means that no eggs are released and the women cant get pregnancy, the drug FSH and LH are given to stimulate ovulation
63
pros of hormone tablets used to increase fertility
it helps women get pregnant
64
cons of hormone tablets used to increase fertility
- doesnt always work so some women have to do it many times which can be expensive
- too many eggs can be stimulated causing unexpected multiple pregnancies
65
what is IVF
a treatment for women whos oviduct is blocked, has an infection or has been used for a donar egg
66
how does IVF work
1) women are given artificial FSH to stimulate the maturing of eggs followed by LH to stimulate ovulation, the eggs are then collected
2) sperm is then injected into the egg, fertilising it
3) the fertilised egg is then grown into embryos in a laboratory incubator
4) one or 2 of the eggs are transferred into the women's uterus to improve the chance of pregnancy
67
pros of IVF
fertility treatments can give an infertile couple a child
microscope techniques have allowed the baby to constantly monitored and help identify those that are more likely to result in a successful pregnancy through genetic testing
68
cons of IVF
- multiple births can happen if more than one embryo grows into a baby increasing the risk of miscarriage
- success rate is low, making the process stressful and upsetting if there are multiple failures
- women can have reactions to the hormones
- requires advanced microscopy, high manipulation skill to work on a sperm, egg and embryo without damaging it
69
why are some people against IVF
- it often results into unused embryos that are eventually destroyed, and people think thats its unethical as each embryo is a potential human life
- genetic testing of embryos before implantations also raises ethical issues as some think it could lead to the selection of preferred characteristics
70
what is adrenaline
a hormone released by the adrenal glands
71
why is adrenaline released into the body
in response to stressful or scary situations as your brain detects fear or stress and sends nervous impulses to the adrenal gland which response by secreting adrenaline
72
what does adrenaline do
prepares your body for fight or flight by triggering mechanisms that increase the supply of oxygen and glucose to cells in the brains and muscles
73
where is thyroxine produced
thyroid gland
74
what does thyroxine do
regulates your basal metabolic rate and stimulates protein synthesis
75
when is TSH (thyroid stimulating hormones) produced
its produced when the level of thyroxine is too high or low
- when the levels of thyroxine are high TSH is produced to inhibit it
- when the levels of thyroxine are low TSH is produced to stimulate it
76
what is auxin
a plant hormone that control growth near the tips of the shoots and roots
77
what does auxin do
controls the growth of a plant in response to light (phototropism) and gravity (geotropism)
78
where is auxin produced
in the tips and moves backwards to stimulate the cell elongation processes behind the tips
79
what happens if the tip of a shoot is removed
no auxin is available and the shoot will stop growing
80
what does extra auxin do
promotes growth in the shoots but inhibits growth in the root
81
what happens during phototropism
- when the shoot tip is exposed to light, more auxin accumulates on the side that's in the shade
- this makes the cells elongate faster on the shaded side so the shoot bends towards the light
82
what happens during geotropism
- when a shoot is growing sideways, gravity produces an unequal distribution of auxin in the tip, with more auxin on the lower side, this causes the lower side to grow faster, bending the shoot upwards
- a root growing sideways will have more auxin on its lower side but in a root extra auxin inhibits growth, this means that the cell on top will elongate faster and the root will bend downwards
83
what plant hormones have commercial uses
- auxins
- gibberellin
- ethene
84
what are auxins commercial use
- weed killers - selective weed killers are made using auxins which only affect certain plants by disrupting their growth pattern, causing them to die
- growing from cuttings with root powder - if you plant a plant cutting with root powder which contains auxins it will produce roots rapidly and start growing new plants, this enables growers to
- produce clones of a good part of a plant
growing cells in tissue culture - tissue culture can be used to grow clones of a plant from a few of its cells by adding auxins to the growth medium to stimulate the cells to divide to form roots and shoots
85
what are gibberellin commercial use
- control dormancy - seeds can be treated with gibberellins to alter dormancy (conditions the plant needs to germinate) and make them germinate at any time of the year and also makes sure that all the seeds in a batch germinate
- induced flowering - plants treated with gibberellin can flower without any change in their environment and can grow bigger flowers
- growing larger fruit - ig gibberellin is added to seedless fruits they will grow larger to match seeded fruits
86
what are ethenes commercial use
- used to speed up the ripening of fruit either while they are still on the farm or during transport to shops, this means that the fruit can be picked while its unripe whilst its firmer, so it cannot be damaged easily, the gas is then added to the fruit on the way to the supermarket so it will be riped when it reaches the shelves
- ripening can also be delayed while the fruit is in storage by adding chemicals that block ethenes effect, by reducing the amount of ethene produce by the fruit or by using chemicals that react with ethene to remove it from the air
87
what is gibberellins
a plant hormone that stimulates stem growth, seed germination and flowering
88
what is ethene in plants
a gas produced by ageing parts of the plant and influences the growth of the plant by cell division and stimulates enzymes that causes fruit to ripen
89
REQUIRED PRACTICAL - how light intensity affects the growth of seedlings
1) place cotton wool in 3 petri dishes then soak them with equal volumes of water
2) place 10 mustard seeds in each dish
3) leave the dishes in a warm place and allow the seeds to germinate by watering the seeds every day with the same volume of water
4) when the seeds germinate we have to make sure the dishes have the same number of seedlings
5) use a ruler to measure the height of each seedling (make sure the stems are straight)
6) place dish 1 in full sunlight, dish 2 in darkness and dish 3 in partial light
7) measure the height of each seedling every for 5 consecutive days and record the results, then calculate the mean
90
Variables for REQUIRED PRACTICAL
I - light intensity
D - height of the seedling
C - volume of water, type of seed, number of seedling
91
why do seedlings in the dark grow rapidly and turn yellow
as seeds usually germinate underground and they grow rapidly to reach the light
- the seeds turn yellow as once they use all their energy stores that cannot carry photosynthesis in the dark
