Sexual Reproduction 🌼💖

Frogs require water for reproduction 💧 because their eggs and larval stages need oxygen from water 🌊. Mature male frogs attract females by croaking 🎶🎵. During mating, the male mounts the female in the water, initiating copulation. The female produces a large number of eggs 🥚✨, which are fertilized externally by the male's spermatozoa. Once laid, the eggs develop on their own without parental care. Each egg contains yolk, providing essential nutrients for the embryo until it hatches into a tadpole 🐸. Tadpoles move through water using their tails and breathe through gills 🌊🐠.

Male Reproductive System 🧔💪

• Testes: Produce sperm and secrete testosterone 💪🔥; located in the scrotum outside the lower abdomen to maintain a cooler temperature for optimal sperm production.
• Epididymis: Coiled tubes where sperm are stored 🧪🔬.
• Sperm Duct (Vas Deferens): Carries sperm from the epididymis to the urethra 🚀.
• Urethra: Transports semen from the sperm duct and urine from the bladder 🚽💧.
• Penis: An erectile organ used to deposit semen into the vagina during ejaculation 💦.

Female Reproductive System 👩🌷

• Ovaries: Produce eggs and secrete hormones such as estrogen and progesterone 🌺💖.
• Oviduct: Transports the ovum from the ovary to the uterus; site of fertilization 🌈.
• Uterus: The implantation and development site for the fetus 🤰🌱.
• Cervix: Connects the vagina to the uterus, serves as part of the birth canal, and secretes fluids for lubrication 💧.
• Vagina: The passage where the penis is inserted during intercourse and part of the birth canal 🌸.

Male Secondary Sexual Characteristics 🧔💪

• Sperm production 🥚💧
• Enlargement of testes and penis 📈🍆
• Development of body hair (pubic, facial, and chest hair) 🌿🧔

Female Secondary Sexual Characteristics 👩🌸

• Onset of the menstrual cycle 🩸🌙
• Enlargement of breasts 🍈💖
• Widening of hips 🍑📏

The menstrual cycle lasts about 28 days, alternating between ovulation and menstruation:

• Ovulation: Release of an ovum from the ovary 🌕✨.
• Menstruation: Shedding of the uterine lining when fertilization does not occur, lasting 3 to 5 days 🗓️.

Hormonal Regulation ⚖️💊

• Follicle Stimulating Hormone (FSH): Stimulates egg development in ovaries 🌱.
• Estrogen: Builds up the uterine lining, inhibits FSH secretion, and stimulates Luteinizing Hormone (LH) secretion 🌼.
• Luteinizing Hormone (LH): Triggers ovulation and formation of the corpus luteum 🌟.
• Progesterone: Maintains uterine lining and blood supply, inhibits FSH and LH 💖.

If fertilization occurs, the corpus luteum remains active until the placenta develops.

• Fertilization: Fusion of male and female gametes (sperm and egg) in the oviduct, forming a zygote 💞✨.
• Embryo Development: The zygote divides and travels to the uterus, where it implants about 11 to 12 days after fertilization 🗓️.
• Fetus Formation: After 6 to 8 weeks, the embryo becomes a fetus as vital organs develop 🏥.

The Placenta 🥰🌼

The placenta performs functions similar to the intestines, kidneys, and lungs:

• Attaches the fetus to the uterus 🤱❤️
• Protects the fetus from the mother’s immune system and pathogens 🦠🛡️
• Exchanges materials (nutrients, gases) via diffusion through villi 🌬️💨
• Secretes hormones (progesterone and HCG) to support pregnancy 🤰💖.

Risks: Harmful substances (e.g., carbon monoxide, alcohol, and certain viruses) can cross the placenta, potentially harming the fetus.

Umbilical Cord 🧵💖

The umbilical cord contains blood vessels that transport waste from the fetus to the placenta and nutrients from the placenta to the fetus 🚼.

Amnion and Amniotic Fluid

The amnion surrounds the fetus in amniotic fluid, which protects against shocks, prevents drying, and maintains a stable temperature.

Note: The mucus plug prevents foreign substances from entering the uterus during pregnancy.

The gestation period is the time from fertilization to birth, lasting about nine months for boys and eight months for girls ⏳.

Stages of Birth 🚼🎉

• Dilation: The cervix widens in preparation for delivery, initiated by labor pains caused by oxytocin 💪.
• Delivery: Expulsion of the baby from the uterus, typically with the head emerging first 👶.
• Afterbirth: Expulsion of the placenta from the uterus 🌸.

Birth control involves limiting the number of children and spacing births for several benefits:

• Allows maternal recovery after childbirth.
• Ensures adequate resources (nutrition, education) for each child.

Methods of Birth Control 🚫👶

Natural Methods 🌱🌼

• Withdrawal Method: Removal of the penis before ejaculation; unreliable due to pre-ejaculate sperm 🚫.
• Rhythm Method: Intercourse during the safe period of the menstrual cycle; unreliable due to cycle variations 📅.

Artificial Methods 💉🔧

• Barrier Methods: Include condoms and diaphragms to prevent sperm entry; condoms also protect against STIs 🛡️.
• Intrauterine Device (IUD): A device that prevents implantation; must be fitted by a professional 🩺.
• Chemical Methods: Spermicides kill sperm; hormones (pills/injections) prevent ovulation and implantation 💊.
• Surgical Methods:
  • Vasectomy: Ties sperm ducts; reliable but potentially irreversible 🔒.
  • Tubal Ligation: Ties oviducts; also reliable and usually irreversible 🔒.