Spermatogenesis, Oogenesis, Embryonic Development & Reproduction
Spermatogenesis
The formation of sperm, called spermatogenesis, is conducted in the seminiferous tubules of the testicles. Spermatogonia-containing sperm are propelled into the epididymis. These ducts subsequently become the internal deferens. The lining of these ducts is made of ciliated cells that enable the advancement of sperm to the urethra. The seminal vesicles and prostate secretions incorporate nutrients that nourish the sperm to form semen.
Female Reproductive Tract Development
Along embryonic development, reproductive structures are precursors of the same in both sexes. From the 7th week, unlike the sexes, oogenesis begins during embryonic development. In the ovaries, oocytes form that are surrounded by the primary follicle cells and a set of nutritive cells. The oocytes initiate meiosis to form gametes. This occurs during puberty, between 10 and 14 years of age.
- Growth: The pituitary gland produces growth hormone.
- Reproductive system maturation: The production by the pituitary of luteinizing hormone and follicle-stimulating hormone causes the synthesis of estrogens, female sex hormones.
Estrogens produce an increase in the size of secondary sexual characteristics, such as breasts, widening of the hips, and hair growth in the pubis.
Embryonic Development
- The nervous system, eyes, ears, nose, and mouth begin to form. At the end of the first trimester, the embryo weighs about 20 grams and measures 10 cm.
- Full development of all organs of the new being, thereafter called a fetus. The fetus is actively moving, and the mother can feel the movements. Upon reaching the sixth month, the weight is about 900g.
- Complete the maturation of the organs. The fetus is placed upside down for birth.
Stages of Childbirth
- Dilation: Uterine contractions become more frequent, widening the uterus. When the cervix reaches 10cm dilated, the phase ends.
- Expulsion: Uterine contractions continue, and at the same time, the fetus makes its way outward, pushing with the head. The umbilical cord is clamped to prevent bleeding, then cut.
- Delivery: The delivery of the placenta occurs after the delivery of the fetus.
Assisted Reproduction Techniques
- Hormone therapy to induce ovulation is prescribed in cases of disorders in the functioning of the ovaries.
- Artificial insemination is the introduction of washed semen from the man into the fallopian tubes of the woman.
- In vitro fertilization is to encourage the union of egg and sperm in a laboratory container.
Contraception Methods
Periodic Abstinence Method
Based on exact knowledge of the day of ovulation, thus avoiding sex during the fertile period of the menstrual cycle. Examples include the Basal Body Temperature Method and the Ogino-Knaus method.
Barrier Methods
These methods are based on preventing sperm from reaching the uterus and fallopian tubes.
- Male Condom
- Diaphragm
- Female Condom
Chemical Methods
Based on the use of chemicals that can alter the cells involved in fertilization or inhibit their formation.
- Spermicide
- Anovulatory (Birth control pills)
IUD (Intrauterine Device)
A flexible, T-shaped device is inserted into the uterus, altering the endometrium and thus inhibiting implantation.
Surgical Methods
These are sterilization methods.
- Vasectomy
- Tubal Ligation