Topic 10 Hormones Flashcards
(37 cards)
Describe the endocrine system
a system composed of glands which secrete chemicals called hormones directly into the bloodstream.
What does the blood help the hormones with?
The blood carries the hormone to a target organ where it produces an effect.
Compare the endocrine system with the nervous system.
Nervous system:
Very fast actions act for a very short time and act on a very precise area
Endocrine systems:
Slower action
Act for a LONG TIME
Act in a more GENERAL way
The pituitary gland is the gland in the ——— and can be described as the———-
It:
brain
master gland
secretes several hormones into the blood in response to body conditions. These hormones in turn act on other glands to stimulate other hormones to be released.
Identift the different glands:)
Ignore arrow five and three
- Pituitary gland
- Thyroid
- Adrenal
- Pancreatic
- Ovary
- Testes
Describe how reproductive hormones cause secondary sex characteristics to develop at puberty.
In men, the main reproductive hormone is testosterone. It’s produced by the testes and stimulates sperm production. As well as the development of facial hair.
In women, the main reproductive hormone is oestrogen. It’s produced by ovaries. As well as bringing about physical changes like development of breasts and periods.
Describe how the menstrual cycle is regulated by four hormones. State where the hormones are produced and how they affect a woman’s body:
- FSH (Follicle Stimulating Hormone) is produced in the pituitary gland. Causes an egg to mature in one of the ovaries, in a structure called a follicle. Stimulates the ovaries to produce oestrogen
- Oestrogen
produced in the ovaries. Causes the lining of the uterus to grow. Stimulates the release of LH (which causes the release of an egg) and inhibits release of FSH. - LH (Luteinising Hormone)
Produced by the pituitary gland
Stimulates the release of an egg at day 14 (ovulation) - Progesterone
Produced in the ovaries by the remains of the follicle after ovulation. Maintains the lining of the uterus during the second half of the cycle. When the level of progesterone falls, the lining breaks down.
Inhibits the release of LH and FSH
List barrier methods of contraception and what they do:
condoms and diaphragms which prevent the sperm reaching an egg
intrauterine devices do what:
prevent the implantation of an embryo or release a hormone
Describe female and male sterilisation and its effects
in female this involved the cutting or tieing of tubes (which connect the ovaries to the uterus) or the sperm duct (the tube between the testes and penis) in a male. This is a permanent procedure however, there is a very small chance that the tubes can rejoin.
spermicidal agents which
kill or disable sperm
Natural methods of avoiding pregnancy
abstaining from intercourse when an egg may be in the oviduct
general abstinence
How do oral contraceptives work:
contain hormones to inhibit FSH production so that no eggs mature
injection, implant or skin patch contraceptives use
slow release progesterone to inhibit the maturation and release of eggs for a number of months or years.
what is a diaghragm and how does it work?
a shallow plastic cup that fits over the cervix to form a barrier and had to be used with spermicides
Explain the use of hormones in modern reproductive technologies to treat infertility:
Some women have levels of FSH that are too low to cause eggs to mature. This means that no eggs are released and the women can’t get pregnant.
FSH and LH can be given as a fertlity drug to stimulate ovulation.
Describe In Vitro Fertilisation (IVF) treatment.
IVF involves giving a mother FSH and LH to stimulate the maturation of several eggs.
The eggs are collected from the mother and fertilised by sperm from the father in the laboratory.
The fertilised eggs develop into embryos.
At the stage when they are tiny balls of cells, one or two embryos are inserted into the mother’s uterus (womb).
Evaluate IVF and understand and talks about tech adanvancements
Although fertility treatment gives a woman the chance to have a baby of her own:
it is very emotionally and physically stressful some women have strong reactions to the hormones e.g abominal pain dehydration and vomiting
the success rates are not high
it can lead to multiple births when too many eggs are stimulated which are a risk to both the babies and the mother. This is because there is a higher risk of miscarriage and still birth
Advances in the have improved IVF:
-microscope techniques more succesful
-micro tools have been developed to remove single cells from the embryo for genetic testing
- time-lapsing imaging so development of embryos an be monitored continuously
Explain the roles of thyroxine and adrenaline in the body.
Adrenaline is produced by the adrenal glands in times of fear or stress. It increases the heart rate and boosts the delivery of oxygen and glucose to the brain and muscles, preparing the body for ‘flight or fight’.
Thyroxine from the thyroid gland stimulates the basal metabolic rate. It plays an important role in growth and development
Thyroxine levels are controlled by ———————–
the pituitary gland in the brain
Plants produce hormones to coordinate and control growth and responses to light ——–
and to gravity ————
phototropism
gravitropsim or geotropism
Gibberellins are important in initiating :
Gibberellins can be used to:
seed germination
end seed dormancy
promote flowering
increase fruit size
Ethene controls :
It is used in the food industry to control:
cell division and ripening of fruits
ripening of fruit during storage and transport.
Auxins are used:
as weed killers
as rooting powders
for promoting growth in tissue culture.
