Reproductive System

1. Reproductive System Silvia Prelez & Mariana Simón 11A

2. Female anatomy- urinogenital system Fallopian tube (oviduct) – Carries ovum to the uterus. Fertilisation takes place in the oviduct. Ovaries – Contains follicles which develop ova. Produces oestrogen and progesterone Uterus (womb) – where fetus develops Cervix – neck of uterus Bladder – part of urinary system- stores urine. Uterus lining – Where implantation takes place Vagina – Receives penis during intercourse. Also serves as birth canal Clitoris – Highly sensitive organ found outside of the vagina Vulva – Vagina opening

3. Male anatomy- urinogenital system Sperm duct – carries sperm from testes to urethra Prostate gland – helps produce seminal fluid (99.5% of semen) Urethra – carries semen from sperm duct to tip of penis Penis – becomes erect when blood spaces are filled. Testes – made up of coiled tubes (epididymis) which produce sperm, also produces testosterone

4. Secondary sexual characteristicsand puberty hormones Male Female Changes in behavior: become maternal and attracted to boys. Pituitary hormone stimulates ovaries to produce oestrogen. Stimulates development of secondary sexual characteristics. Oestrogen begins cycle of egg production and prepares uterus lining. Breasts develop and grow, as do nipples. Hair develops under armpits and in pubic region. Hips broaden, pelvis widens and fat is deposited. Vagina becomes larger • Changes in behavior: may become aggressive, territorial and attracted to girls. • Pituitary hormone stimulates testes to produce testosterone. Stimulates development of secondary sexual characteristics. • Hair develops on face, chest, armpits and pubic region. • Chest broadens, muscles enlarge, voice deepens due to larynx shape changing. • Testes are stimulated to produce sperm. • Penis becomes larger and scrotum expands

5. Menstrual Cycle

6. Menstrual cycle: phases • Phase 1 (Days 1-5) Menstruation: Uterus lining is shed, and blood and fragments of tissue leave body through the vagina. Menstruation is triggered by a decrease in progesterone. • Phase 2 (Days 6-12) Repair phase: Uterus lining thickens and becomes stable. Triggered by an increase in oestrogen. • (Days 13-15) Ovulation: Ovum released from ovary. • Phase 3 (Days 16-21) Receptive phase: Uterus lining is well developed. If fertilization has taken place, implantation can occur. (Maintained by increasing level of progesterone.) • Phase 4 (Days 22-28) Premenstrual phase: Uterus lining degenerates, progesterone levels start to fall, unless implantation has occurred (in which case progesterone levels are constant).

7. Menstrual cycle: hormones • Follicle stimulating hormone (FSH) – Released by pituitary gland. Stimulates development of the Graafian follicle in ovary. FSH is present in the first 14 days of the cycle-from the beginning of the development of the follicle until ovulation. • Oestrogen – Repairs the lining of the uterus and stimulates development of female sexual characteristics. Levels are highest in 14th day of cycle. • Luteinizing hormone (LH) – Responsible for stimulating the release of mature ovum from ovary (triggers ovulation) and development of corpus luteum. Levels peak on 14th day of cycle and gradually decrease. • Progesterone – Keeps uterus lining ready for implantation and pregnancy. Levels will be high from 14th to 28thday of cycle. If implantation occurs, progesterone concentration will remain high and constant until childbirth.

8. Copulation and Conception Ovulation Production of semen/ejaculation This process delivers male gametes (sperm) Sexual stimulation causes blood to flow into a man’s penis, making it erect as to allow it to enter a woman’s vagina. This will result in sexual intercourse or copulation. • This process provides a female gamete (ovum) • Occurs monthly when an ovum is released from the ovaries along the oviduct to the uterus. Movement issued by peristaltic movements and cilia in the fallopian tubes. Copulation The rubbing of the tip of the penis (glans) against the wall of the vagina sets of a reflex action (ejaculation) where stored sperm from the man’s testes passes by peristalsis through the sperm ducts and along the urethra. In these tubes, seminal fluid is added to the sperm to form semen. The semen is then ejaculated with an approximate amount of 300 000 000 sperm, which will potentially impregnate the woman.

9. Contraception • Chemical Contraception Methods • Spermicide – chemical applied as a cream, which kills sperm • Contraceptive pill – hormone pills which either cause changes in uterus lining to avoid implantation or prevent ovulation • Morning-after pill – Not for regular use, to take after intercourse • Spermicide is a very unreliable method on its own, meanwhile the contraceptive pill is almost 100% effective if used properly and excluding factors like vomiting and diarrhoea. • Physical barrier Methods • Very common devices (especially condom) because of cheap price and relatively easy application. • IUD – copper coil inserted in uterus. Irritates uterus lining so implantation does not occur • Condom – thin rubber covering fitted over erect penis where semen is collected at ejaculation • Femidom – thin sheath which lines vagina preventing entry of sperm • Diaphragm – thin rubber barrier preventing sperm to enter uterus Preventing pregnancy- There are four categories in which contraception can be divided into:

10. Contraception • Natural Contraception Methods • These ‘rhythm methods’ are used by couples who avoid having intercourse during the woman’s fertile period, waiting for the safe period when it is unlikely that fertilization will take place. • Calendar method – time of ovulation is calculated • Temperature method – body temperature is measured and changes at ovulation are observed • Mucus method – changes in mucus lining of vagina and cervix at ovulation • These techniques are known to not be very reliable. Although people with various religious beliefs may favor them. The failure rate for these methods are 15/HWY • Surgical Methods • Since these methods are difficult to reverse they should mostly be considered by couples who are sure that they do not want to have children. • Vasectomy – sperm ducts are cut or tied in a surgical operation • Female sterilization – oviducts are tied and cut during an operation. This method is 100% reliable.