B11 Flashcards
what is the endocrine system
the endocrine system is another response system in the human body. its made up of hormones and glands
what is a hormone
A hormone is special chemical messenger secreted by glands
how do hormones travel around the body
through the bloodstream
is the endocrine system faster than the nervous system
no
3 differences between the endocrine system and the nervous system
endocrine system is slower, longer lasting and uses chemicals
where is the pituitary gland located
in the brain
where is the thyroid gland located
at the base of the neck
where is the adrenal gland located
just above the kidneys
where is the pancreas located
middle of the stomach
what hormones do the pituitary gland produce and the roles of the hormone
ADH - causes blood water levels to rise
FSH - cause the egg to mature
LH - causes ovulation of the egg
TSH - thyroid stimulating hormone
what hormones does the thyroid gland produce
Thyroxine - controls the metabolic rate
what hormone does the adrenal gland produce
adrenaline - stimulates the fight or flight response
what hormones do the pancreas make
insulin - converts glucose to glycogen
glucagon - converts glycogen to glucose
what hormones do the ovaries make
oestrogen - repairing the uterus lining
progesterone - maintains the uterus lining
what hormones do the testicles produce
testosterone - used in the production of sperm
what happens if the glucose levels are too high
insulin is released by the pancreas and so the glucose moves into the cells and is converted into glycogen. glycogen is then stored in the muscles and the liver. blood glucose levels fall
what happens if the blood sugar levels are too low
glucagon is released. glycogen is converted into glucose. blood glucose levels are risen.
what is type 1 diabetes
its when the pancreas doesn’t produce enough insulin
what is type 2 diabetes
its when the body doesn’t respond to the insulin produced
how is type 1 diabetes treated
by using insulin injections
how is type 2 diabetes treated
by regular exercise, a healthy diet and losing weight
what is negative feedback
a loop when the opposite of a stimuli happens to bring levels back to normal
the thyroid negative feedback loop in detail please
The pituitary gland releases thyroid stimulating hormones which go to the thyroid gland.
This causes the thyroid gland to make thyroxine which go to the target cells.
When thyroxine levels in blood get higher than the threshold,
Thyroxine levels are detected by the pituitary gland.
This inhibits (stops) the production of TSH.
When TSH levels decrease, the thyroid gland stops producing thyroxine.
When thyroxine levels decrease, this triggers the pituitary gland to start
producing TSH again. This is a negative feedback loop.
what does adrenaline do to the body to prepare it for the fight or flight response
increase blood sugar levels, heart rate and the delivery of oxygen.
which one is controlled by negative feedback:
adrenaline or thyroxine
thyroxine is controlled by negative feedback; adrenaline is not
how long is a menstrual cycle
28 days
what effect does oestrogen have on other hormones
oestrogen stops the production of FSH
what effect does FSH have on other hormones?
FSH causes the ovaries to start making oestrogen
what effect does oestrogen have on other hormones (not fsh) ?
rise in oestrogen levels causes the pituitary gland to start making LH which then causes ovulation to occur.
what effect does progesterone have on other hormones?
progesterone inhibits the production of H
when is LH highest in the menstrual cycle
during ovulation at day 14
why does oestrogen levels increase from days 1 - 14
to cause the uterus lining to thicken
why does the progesterone levels increase after day 14 in the menstrual cycle
maintains the uterus lining
what happens if the progesterone levels fall in the menstrual cycle
it causes the uterus lining to break down (menstruation)
what is glycogen
a complex carbohydrate found mostly in muscles and the liver
what is conception
when the sperm breaches the egg and fertilises it. this is also known as fertilisation.
what is contraception
preventing the sperm from moving through the female reproductive system
what are contraceptive methods
methods or ways to stop fertilisation or pregnancy from taking place. these ways can me chemical, natural, mechanical and surgical
what are some hormonal contraceptives
mixed pill - contains oestrogen and progesterone which inhibits the production of FSH which causes the egg to stop maturing. this also causes the pituitary gland to start making LH which causes the unmatured egg to be released from the follicle.
progesterone only pill - thickens the mucus in the cervix to stop the sperm from reaching the egg.
contraceptive implant - its a tube inserted underneath your skin which slowly releases progesterone which thickens the mucus in the cervix to stop the sperm from reaching the egg
what are some chemical based contraception
spermicide - used to kill/disable the sperm
IUD - releases copper into the womb killing the sperm entered
what are some mechanical based contraceptives
male condom - used to stop the sperm from entering the vagina
female condom - used to stop the sperm from entering the vagina
what are some surgical based contraception
female sterilisation - involves blocking the fallopian tubes
male sterilisation (also known as a vasectomy) - tubes carrying the sperm from the testicles are cut/blocked/sealed off
what are some other contraceptive methods
abstinence - abstaining from sex
what is infertillity
the inability to have a child
what are some fertility treatments for a women
fertility drugs - a pill which contains FSH and LH
what is IVF (in vitro fertilisation)
IVF is a procedure for fertility treatment in which the egg gets fertilised in a lab and is the placed back into the mother
explain the steps that happen in IVF
- FSH and LH are given to the mother so several eggs can mature and be used in IVF
- the eggs are collected from the mother and are then placed back into a petri dish with some sperm from the father
- eggs are double checked to make sure they are fertilised
- the fertilised eggs then turn into small embryos (around 4 cells in total)
5.these embryos are then placed back into the mothers’ uterus
what are some disadvantages of IVF
- can give multiple births
- risk of still births
- pricey procedure
- IVF is not always successful
what are some advantages of IVF
- can give couples a chance to have their own child
- matured egg produced by the women can be stored and used at a later date
what is tropism
growth in response to a stimuli
what is phototropism
when a plant grows in response to light
what is gravitropism
growth of a plant in response to the pull of gravity
what is gravitropism also called
geotropism
where does positive phototropism take place
positive phototropism takes place in the growing tips/shoots of a plant when it grows towards the direction of the sunlight as it gives the plant the ability to get more sunlight
where does positive geotropism take place
in the roots of a plant where the roots grow towards the force of gravity as it gives them a higher chance of finding minerals
where does negative geotropism take place
it takes place in the shoot tips which cause the plant to grow taller and negative geotropism is important for the tips as it gives the plant a higher chance of finding sunlight
where does negative phototropism take place
in the roots of a plant. this is important for the plant as it’ll help the roots not dry out from the sunlight
what is auxin
auxin is a growth hormone in a plant
how does auxin work?
auxin works by growing the area of the plant where the auxin is. e.g if in a shoot tip all the auxin is on the left the left side of the shoot will grow more than the right side causing the shoot to droop to the right side
how does auxin work in positive phototropism
auxin will diffuse away from the side of the shoot with the most light. this causes the side of the shoot with the little light to grow more than the side with more light. this will cause the shoot to tilt to the side with more light causing the plant to get more light.
what happens to the hormone gibberellins during germination
gibberellins breaks down starch and converts it into sugars to be used for energy by the plant.
what does gibberellins do to fruit?
gibberellins stimulates the flowering and the production of fruit and is used to make the fruit seedless or have little seeds and is used to control seed dormancy in plants
how can auxins be used as weed killers
auxin is spread around the area where the weeds grow. this causes the weed to grow large which then causes the weed to grow large fast an so the weed takes in the weed killer from the soil and therefore killing the plant
what is the function of the hormone Ethelyn in the use of fruits and stuff
Ethelyn breaks down the plant cell wall making the fruit softer. It also converts starch into sugars so it makes the fruit sweeter too. it also helps fruits to ripen quicker.
well done
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