B10 Animal and Plant Hormones Flashcards
What happens in stage one of the menstrual cycle?
Menstruation- the lining of the uterus breaks down for about 4 days
Between which days does the uterus lining build back up?
From day 4-14
What occurs in the third stage and when?
An egg is released from the ovary at day 14.
For how long is the wall of the uterus maintained?
14 days, until around day 28
What happens to the uterus wall if no fertilised egg has been received?
The spongy lining breaks down.
What 2 things does follicle-stimulating hormone do?
- Trigger maturation of an egg in an ovarian follicle
- Stimulates the ovaries to produce oestrogen
What does luteinising hormone do?
Stimulates the release of an egg
What 3 things does oestrogen do?
- Causes uterus lining to grow/maintains it
- Inhibits FSH release
- Stimulates LH release
What 2 things does progesterone do?
- Maintains the uterus lining
- Inhibits LH and FSH
The falling level of which hormone causes the uterus lining to break down?
Progesterone
Why can oestrogen be used as a contraceptive?
Maintaining high oestrogen levels inhibits FSH, so egg maturation and therefore egg release will stop.
Why can progesterone be used as a contraceptive?
- Stimulates the production of thick mucus in the cervix which acts as a barrier
- Inhibits egg maturation and release
Which contraceptive pill has the least side effects?
progesterone-only
List 2 benefits of the oral contraceptive pill:
- 99% efficacy
- Reduces risk of some cancers
List 2 disadvantages of the pill:
- Doesn’t protect against STDs
- Side effects- headaches, nausea
What is a contraceptive patch?
A small patch containing oestrogen and progesterone that is stuck to the skin
What is a contraceptive implant?
An implant inserted under the skin that releases progesterone
What is a contraceptive injection?
An injection containing progesterone
What is used with a diaphragm to increase its efficacy?
Spermicide
Where is a diaphragm fitted?
Over the cervix