Reproductive System Flashcards
Ovaries
Produces eggs (ova) durin the foetal stage
Only 500 eggs will mature between puberty and menopause
One egg (ovum) is generally released each month (the ovaries take turns to
release the egg, not necessarily alternate)
Produces female hormones ostrogen and progesterone.
oviduct/ fallopian tube
• Muscular tube leading from ovaries to uterus and transports the mature ovum released from the ovary once every month.
• Site of fertilization, where the sperm meets and fuses with the mature ovum
Uterus
• Has thick, muscular, elastic walls
•Site of foetus development during pregnancy
Inner lining is spongy and filled with blood capillaries → prepare for embryo implantation
Cervix (female)
Circular ring of muscle that dilates to allow passage of baby during birth
Vagina
• Site where semen is deposited in the vagina during sexual intercourse
• Also known as the birth canal
Testes
Produces sperms
Produces male sex hormone, testosterone
Each testis is connected to epididymis
Epididymis
Narrow, coiled tube that stores inactive sperms before they enter the sperm duct
Sperm ducts
Transport sperms released from the testes and subsequently epididymis to urethra
Male sex glands
Contain nutrients and enzymes to help the sperms to swim actively
Penis
Erectile organ that deposits sperms into vagina of female during sexual intercourse
• Blood vessels in the erectile tissue found in penis become filled with blood during sexual arousal.
Urethra
• A tube which passes through the centre of the penis to the exterior.
• Transports urine and semen at different times
Menstruation
The first day of menstruation is the first day of the menstrual cycle.
Takes place when there is no fertilization the previous cycle.
• Thick uterine lining supplied with blood capillaries will breakdown together with unfertilised ovum.
• Discharged out of female’s body through the vagina.
Menstrual discharge consists of blood, uterine lining and the unfertilised egg.
Repair of uterine lining
Repair of Uterine Lining - stimulated by ostrogen
• The uterine lining starts to thicken and blood vessels form inside the thick lining.
Ovulation
During ovulation, a mature egg is released from the ovary.
Ovulation usually takes place about 14 days after menstruation starts. → still may have existing cemen/sperm
• One of the ovaries releases a mature ovum
• ‘Fertile Period’ is usually 3 days before and 3 days after ovulation. (Day 11-17).
Ovum usually can survive for about 12-24 hours after ovulation while sperms can survive within the female for about 3 days.
• If there is no fertilization, the ovum dies and disintegrates
After ovulation, uterus lining further thickens and becomes well-supplied with blood vessels to prepare for the possible implantation of the embryo.
Maintain thickness of the uterine lining
Preparation for fertilisation
• The lining of the uterus is at its thickest
• If there was no fusion between the sperm and ovum (i.e. no fertilization), the thick uterus lining begins to break down.
• If fertilization occurs, the thickness of the uterine lining is maintained to support foetus development
How to prevent pregnancy
-Preventing fertilisation of an ovum (egg) by the sperm cell
-the prevention of implantation of the embryo (fertilized egg) into the lining of the uterus.
-the killing of sperm cells .
-preventing ovulation.
Two measures of birth control
- Temporary
- Permanent
Temporary birth control methods
- Rhythm method
- Spermicide
- Diaphragm
- Condom
- Intra-uterine device
- Contraceptive pills
Rhythm method
This method involves avoiding sexual intercourse during the fertile period of the woman’s menstrual cycle.
Spermicide
Spermicide is a chemical that kills or blocks sperms from entering the uterus.
This reduces the chances of fertilisation.
Spermicide is inserted into the vagina.
Diaphragm
The diaphragm is a dome-shaped rubber cap with an elastic rim.
It is inserted into the vagina and placed over the cervix.
The diaphragm is impermeable and does not allow sperms to pass through. It prevents the sperms from entering the uterus and prevents fertilisation.
Condom
A condom is a thin rubber tube used to cover the erect penis before sexual intercourse.
The condom is impermeable to sperms. Hence sperms cannot enter the uterus and no fertilisation occurs.
The condom is also impermeable to bacteria and virus.
It can protect the user from getting sexually transmitted infections.
Intra-uterine device
The IUD is a piece of plastic or metal that is inserted into the uterus by a doctor. The IUD disrupts the function of the uterus.
It prevents the embryo from being implanted on the uterine lining.
Contraceptive pills
Contraceptive pills contain certain female sex hormones which prevent ovulation. The pills disrupt the function of the ovary and prevents it from releasing a mature egg every month.
