18. Hormones of Menstrual Cycle, Contraception, IVF and plant hormones Flashcards
FSH
Produced in: pituitary gland
- Causes eggs to mature
- Stimulates the ovary to produce oestrogen
Oestrogen
Produced in: ovaries
- Causes lining of uterus to develop
- Inhibits the release of FSH
3: Stimulates release of LH
LH
Produced in: Pituitary gland
1. Triggers ovulation on day 14
Progesterone
Produced in: Ovaries
- Maintains the lining of the uterus
- Inhibits the release of both FSH and LH
Hormone treatment
FSH and LH can be used as a drug to stimulate ovulation in women with low FSH levels
IVF (In Vitro Fertilisation)
Advantage:
-Healthy baby
Disadvantage:
- emotionally stressful
- often unsuccessful
- operation needed
- risky multiple births
- expensive
Condoms
Barrier method, stops sperm from reaching egg
Advantage:
- no side effects
- protect against STIs
Disadvantage:
-can get damaged
surgical sterilisation
e.g sperm ducts cut/tied (vasectomy) in males, oviducts cut/tied in women
Advantage:
100% effective, permanent
Disadvantage:
surgical procedure requires
Intrauterine devices (IUDs)
aka coil, small structure in uterus, lasts 3-5yrs
Advantage:
- v effective
- lasts 3-5 years
Disadvantage:
may cause infections
mixed pill
Contains Oestrogen and Progesterone, so inhibits FSH & LH so no eggs mature
Advantage:
- easily accessible
- can be stopped easily
Disadvantage:
- side effects, e.g high blood pressure
- must remember to take
The implant
a tiny tube under skin, slowly releases progesterone
advantage:
-99.95% effective
disadvantage:
- lasts only 12 weeks
- can cause side effects
phototropism
plant hormone response to light. shoot grows towards light.
gravitropism (aka geotropism)
the plant hormone response to gravity. shoots grow away from gravity, roots grow towards gravity
Auxin
The hormone which controls plants response the light and gravity
Gibberellins
important in seed germination
