B11 Flashcards
Contraception
Methods of preventing pregnancy which involve preventing the sperm and egg from meeting
Examples of contraception(name 3)
Combined Pill
Barrier method(male condom or female diaphragm)
Contraceptive implant
Contraceptive Injection or Skin Patch
Intrauterine devices(IUD)
Examples of oral contraceptives
Oral contraceptives have hormones to reduce fertility.
Examples include:
The combined pill
The mini-pill
How does the combined pill work?
Contains the hormones oestrogen and progesterone which:
Inhibit FSH production(oestrogen does this)
Prevents egg maturation
Prevents ovulation/release of egg by inhibiting LH(progesterone does this)
Mini-pill
A progesterone-only pill
Barrier methods
These are non-hormonal forms of contraception that prevent the sperm reaching the egg
Condoms
Diaphragms
Spermicidal agents which kill or disable sperm
Abstaining from intercourse when an egg may be in the oviduct
Surgical methods of male and female sterilisation
External condoms
Male condoms, worn on the penis,
made from rubber to stop a man’s semen from coming into contact with his sexual partner
Female condoms
Made from soft, thin synthetic latex/latex, worn in the vagina to prevent semen getting to the womb
Diaphragm and caps
Fit inside the vagina and cover the cervix(entrance to the womb), stop sperm meeting an egg
Spermicides
Most spermicides contain nonoxynol-9, a chemical that kills sperms. Examples include cream, gel and foam
Intra-uterine devices
Coil inserted into the uterus to prevent the implantation of an embryo or release of a hormone
Copper IUD- Releases low levels of copper ions which disable sperm cells
Plastic IUD- Produces progesterone which stimulates the production of a thick mucus lining preventing sperm from reaching any eggs.
Contraceptive implant
A small flexible tube inserted under the skin in the upper arm
releasing progesterone in your bloodstream to prevent pregnancy, lasts for 3 years
Contraceptive Injection
Releases the hormone progesterone into the bloodstream to prevent pregnancy, provides contraception for 8-13 years, inhibits maturation and release of eggs, hormone released slowly into the body
Contraceptive patch
Contains oestrogen and progesterone, a small sticky patch releasing hormones into your body through your skin to prevent pregnancy, each patch lasts for 1 week, change the patch every week for 3 weeks, then have a week off without the patch
Natural planning method
Avoiding sexual intercourse during the fertile period of the menstrual cycle when ovulation occurs, requires understanding of fertility signals like:
Length of menstrual cycle
Body temperature changes through the cycle
Changes in cervical secretions through the cycle
Surgical methods
Vasectomy
Female sterilisation(tubal ligation)
Vasectomy
The sperm ducts are cut, so no sperm’s in the semen when ejaculation occurs,
Female sterilisation(tubal ligation)
Oviducts cut/tied off, preventing eggs from reaching the uterus or sperm reaching the eggs
Advantages of combined pill and minipill
Effective when taken correctly
Minipill has fewer side effects than the pill
Disadvantages of combined pill and minipill
Has to be taken every day
A hormonal contraceptive has side effects
Doesn’t protect against STIs
Advantages of injection/implant/skin patch
Lasts for weeks or months so no need to remember daily
Disadvantages of injection/implant/skin patch
A hormonal contraceptive has associated side effects
Doesn’t protect against STIs
Requires a medical professional to implement
Advantages of condom/femidom and diaphragm
Effective when used correctly
Protects against STIs
No side effects
Disadvantages of condom/femidom/diaphragm
Must be applied each time before sexual intercourse
Can break or split
Advantages of abstinence and family planning
No chemical input so no side effects
Disadvantages of abstinence and family planning
Requires careful control and/or monitoring of the menstrual cycle
Can be impacted by illness and lifestyle
Advantages of sterilisation(vasectomy and tubal ligation)
Can be permanent
Disasvantages of sterilisation(vasectomy and tubal ligation)
Difficult to reserve
Involves surgery
Doesn’t protect against STIs
Reproductive hormones
Oestrogen
Testosterone
Oestrogen
Female sex hormone that controls the development of secondary sexual characteristics
Testosterone
The main male sex hormone controlling the male secondary sexual characteristics at puberty and the production of sperm
Stages of the menstrual cycle
1) Day 1- menstruation starts. The uterus lining breaks down for four days.
2)Days 4-14: The uterus lining builds up again into a thick spongy layer full of blood vessels, ready to receive a fertilised egg
3) Day 14- An egg develops and is released from the ovary(ovulation)
4) The wall is maintained for 14 days until Day 28. If no fertilised egg has landed on the uterus wall by day 28, the spongy lining breaks down and the whole cycle starts again.
Changes to boys and girls in puberty
Development of facial hair(boys)
Development of breasts(women)
Underarm hair grows(boys and girls)
Pubic hair grows(in boys and girls)
Stronger body odour(in boys and girls)
Hips get wider(in girls due to oestrogen)
Voice gets deeper(in boys due to testosterone)
Difference between nervous + hormonal action
Nerves:
Very fast action, act for a very short time, act on a very precise area.
Hormones:
Slower action, act for a long time, act in a more general way
Which gland produces testosterone
The testes
Three hormones produced by the pituitary gland
The anti-diuretic hormone
Follicle stimulating hormone
Lutenising hormone
The anti-diuretic hormone
Controls the water balance of the body and affects the amount of urine produced by the kidney
How scientists are working to find a cure for type 2 diabetes
There are drugs to make insulin more effective on body cells, help the pancreas make more insulin or reduce the amount of glucose absorbed from the gut
How changes in uterus lining adapt for function if egg is fertilised
Increased thickness/build up
for attachment of zygote/sozygote can implant
Gives room for increased blood vessels to provide mutrients for zygote
Becomes thicker to form the placenta
Negative feedback involving insulin
If blood glucose levels are too high, the pancreas produces insulin which stimulates the liver and muscles to lower blood glucose levels, which in turn reduces the rate of insulin secretion. Overall negative feedback keeps fluctuations in sugar to a minimum
What happens in hyperthyroidism?
Too much thyroxine is released into the blood,which raises BMR(energy body needs to maintain homeostasis).
This means an increase in the formation of glycogen/lipids/proteins and in the rate of respiration
How effective would using donors for treating diabetes be compared to insulin injections!
There is a greater risk of infection from the donor than insulin injections
Why is it dangerous if someone has a condition where information from the skin doesn’t reach the brain?
The person is unable to co-ordinate
Possibility of permanent damage
Where in the body are cells sensitive to changes in position?
Ears
Difference between a neurone and a nerve cell
A neurone is an individual nerve cell.
A nerve is a bundle of many neurones
Coordination centres
Areas that receive and process the information from the receptors, that also co-ordinate the response of the body
e.g.
Brain(for nervous system and hormonal system)
Spinal cord
Curing Type 1 Diabetes
Doctors can transplant a pancreas successfully, but the operations are difficult and risky. Not emough pancreas donors are available for everyone who has diabetes.
Transplanting the pancreatic cells making insulin from both dead and living donors has been tried, with limited success so far.
Genetically engineered bacteria to produce human insulin and genetically engineering pancreatic cells from mice to produce insulin
Curing Type 1 Diabetes
Insulin injections - but these don’t cure type 1 diabetes
Regular exercise
Carbohydrate-comtrolled diet
Stages of treating type 2 diabetes
1) People can restore their normal blood glucose balance by:
carbohydrate-controlled diet
losing weight
regular exercise.
2)If this doesn’t work, there are drugs that:
Help insulin work better on the body cells
Help your pancreas make more insulin
Reduce the amount of glucose you absorb from your gut.
3) If none of these treatments work, you need insulin injections.
What is BMR?
The energy the body needs to maintain homeostasis
Homeostasis controlled conditions
Control of blood glucose concentration
Body temperature
Water level
What is the nervous system responsible for?
The nervous response(electrical impulses)
What is the endocrine system responsible for?
The chemical response(controlled by hormones travelling through the bloodstream)
Adrenaline target organ
Vital organs, heart and liver
Target organ of oestrogen and progesterone
Uterus
Endocrine system speed of transmission
Usually slow, compared to a very rapid speed of transmission in the nervous system
Effects in endocrine and nervous system
In endocrine systems, the effects can be widespread, while in the nervous system the effects are localised
Duration of response in the endocrine and nervous system
Long-lasting(hours) response in endocrine system, while in the nervous system the response is usually brief(seconds).
When is type 1 diabetes usually diagnosed?
Childhood/early adulthood
Risk factors(Type 1 diabetes)
Family history
When is type 2 diabetes usually diagnosed?
Adulthood
Thermoregulation
An example of negative feedback, if body temperature changes, mechanisms are induced
Thermoregulation(negative feedback)
1) If the body temperatures decrease, heating mechanisms are activated(shivering), but the body temperature increases to return to normal homeostatic level.
2) If the body temperatures increase, cooling mechanisms are activated(sweating), but the body temperature decreases to return to normal homeostatic level.
Effects of adrenaline
Glycogen stored in liver is converted to glucose for respiration
Increased heart rate and breathing rate to deliver more oxygen to the brain and muscles for respiration
Pupils dilate to let in more light
Blood flow to muscles/digestive system is increased
Hormonal contraceptive methods
Pill
Contraceptive injection
Coil
How is oestrogen a method of contraception?
Oestrogen is taken daily t9 keep level high, inhibiting the production of FSH, but after some time egg development and production stop
Reflex arc
The pathway in which the electrical impulse travels through the spinal cord instead of straight away going into the brain
Endocrine and nervous systems(where messages are sent to)
Endocrine system - Cells throughout the body
Nervous system - A specific cell or tissue
Hypothalamus
The sensitive centre in the brain controlling the pituitary gland
If the egg’s not fertilises
Follicle forms a yellow body(corpus luteum) and the egg dies
When are fertility drugs used?
If the fallopian tubes are damaged
If a donor’s required
If there’s no obvious cause for infertility
