B11 - hormonal control fact test Flashcards
what are hormones
hormones are chemical messengers, released by glands, which travel in the blood plasma to activate target cells
what are the 4 main conditions we need to keep constant
- water
- body temperature
- blood glucose levels
- ion levels
what is the name of
the endocrine system
what is the difference in speed between nerves and hormones
nerves are a fast action, hormones are a slow action
what is the difference in duration between nerves and hormones
nerves act for a short time, hormones act for a long time
what is the difference in impact between nerves and hormones
nerves act on a very precise area, hormones act in a more general way
what controls blood glucose concentration
the pancreas
when is insulin released
when blood glucose levels are too high
what is the function of insulin and how does it carry out its function
its function is to reduce blood glucose levels
it does this bye:
- causing glucose to move from the blood into cells to be used for respiration
- converting glucose into glucagon to be stored in the liver and muscles
what is the function of glucagon and how does it carry out its function
its function is to raise blood glucose levels
it does this by:
- causing glycogen from the liver to be broken down and released into the blood as glucose
when is glucagon released
when blood glucose levels are too high
how does diabetes type 1 occur
pancreas does not make enough (or any) insulin therefore blood glucose concentration is not controlled
what are some treatments for diabetes type 1
- insulin injections
- pancreas transplant
- transplanting pancreatic cells
- insulin-secreting cells from embryonic stem cells
- mouse pancreas cells into insulin producing cells
how does type 2 diabetes occur
pancreas still makes insulin, maybe less than needed. cells stop responding properly to the insulin you make. more common in people who are older, obese and don’t do exercise
what are some treatments for type 2 diabetes
- eating a balanced diet with controlled amounts of carbohydrates
- losing weight
- doing regular amounts of exercise
- drugs help insulin work better on body cells
- drugs help pancreas make more insulin
- insulin injections
- drugs help reduce the amount of glucose you absorb from your gut
when and where is adrenaline produced
produced in the adrenal glands in times of fear or stress
what changes does adrenaline cause
increases heart rate, therefore boosting delivery of oxygen and glucose to brain and muscles, preparing body for fight or flight
causes heart and breathing rate to increase, stored glycogen to be converted into glucose for respiration, pupils dilate to let in more light, mental awareness to increase, blood diverted away from digestive system to big muscles in limbs
when do adrenal glands stop producing adrenaline
once danger has passed, body returns to resting level
how do negative feedback loops work
- if the level of something rises, control systems reduce it again
- if the level of something falls, control systems raise it again
where is thyroxine secreted from
the thyroid gland
what happens when thyroxine levels increase
it is detected by receptors in the hypothalamus. this inhibits the release of TSH. this inhibits the release of thyroxine, so levels fall
what does thyroxine do
controls basal metabolic rate and plays an important role in growth and development
what happens when thyroxine levels fall
TSH levels rise, so thyroxine levels rise and return to normal
what are secondary sex characteristics in boys and girls
- pubic hair grows
- underarm hair grows
- sexual organs grow and develop
what are secondary sex characteristics in boys only
- voice breaks
- hair grows on face
- body becomes more muscular
- testosterone is produced by testes, stimulates sperm production
what are secondary sex characteristics in girls only
- voice deepens slowly
- hips get wider
- breasts develop
- oestrogen produced by ovaries, stimulates oestrogen production
what is puberty
the stage where a child’s body develops into an adult’s body, these changes occur gradually
what does FSH do
causes the maturation of the egg in the ovary, produced in the pituitary gland, stimulates ovaries to produce oestrogen
what does oestrogen do
causes the lining of the uterus to grow again, produced in the ovaries, stimulates production of LH and inhibits production of FSH
what does LH do
resultes in ovulation, produced in the pituitary gland, produced as a result of oestrogen
what does progesterone do
maintains the lining of the uterus and supports a pregnancy, produced in the ovaries, inhibits the release of FSH and LH
what is the contraceptive pill
contains artificial oestrogen and progesterone, inhibits FSH production so no eggs mature
what does the contraceptive injection do
releases progesterone into the bloodstream to prevent pregnancy, lasts for 13 weeks
what does the implant do
small, flexible plastic rod placed under the skin, releases progesterone to prevent pregnancy, lasts 3 years
what does the skin patch do
sticky patch releases hormones through skin
what do condoms do
prevent sperm reaching egg and protect against STIs
what do diaphragms do
prevent sperm from reaching egg
what does an IUD do
prevents implantation of an embryo. small T-shaped plastic/copper device that releases copper into the womb which alters cervical mucus, making it harder for sperm to survive
what do spermicides do
contraceptive substance that destroys sperm
what is abstinence
don’t have intercourse
surgical sterilisation
fallopian tubes are blocked, vasectomy
what is infertility
is when a couple can’t conceive despite having regular, unprotected sex
what are the 3 main types of treatment for infertility
- medicines
- surgical procedures
- assisted conception (IVF)
what hormones are given to women who do not make enough FSH
- FSH to stimulate maturation of eggs
- LH to trigger ovulation
what is the process of IVF
- woman is given FSH followed by LH to stimulate maturation and ovulation of eggs
- eggs are collected and fertilised by sperm from dad in a lab
- left to develop into embryos, when they are tiny balls of cells, one or two are inserted into the woman’s uterus
what is the advantage of IVF
gives a woman a chance to have a child of her own
what are the disadvantages of IVF
- expensive for society (NHS) or individuals
- use of fertility drugs have health risks for mother
- emotionally and physically stressful
- success rates are not high
- can lead to multiple births, risk for mother and baby
- embryos can be stored - ethical issues as to what if they aren’t wanted anymore
what is phototropism
plants produce hormones to coordinate and control growth and responses to light
stems grow towards light and roots away from the light
what is geotropism
plants produce hormones to coordinate and control growth and responses to gravity
stem grows away from force of gravity and roots grow towards force of gravity
what are auxins
family of plant hormones that are mostly made in the tips of growing stems and roots (meristems)
what do auxins do
control growth of plants by promoting cell division and causing elongation in plant cells
what does a high concentration of auxins cause
cells in stems grow more and cells in roots grow less
what effect does phototropism have on auxins
auxins gather on shaded side of plant
what effect does geotropism have on auxins
auxins gather at the lowest part of the plant
what do unequal distributions of auxin cause
growth
why are giberellins needed
to initiate seed germination
what does ethene do
controls cell division and ripening of fruits
where are plant growth hormones used
agriculture and horticulture
what are auxins used for
- used as weed killers (makes plant grow so fast it dies)
- used as rooting powders (helps roots develop quickly so plants will grow faster)
- used for promoting growth in tissue culture (a technique used to grow whole new plants from a section of a parent plant)
what is ethene used for
used in the food industry to control ripening of fruit during storage and transport
what are giberellins used for
can be used to end seed dormancy, promote flowering and increase fruit size
