The Reproductive System

Reproduction: Process by which organisms produce offspring. Ensures continuity of species.

Types: (1) Asexual reproduction - single parent, identical offspring, (2) Sexual reproduction - two parents, genetic variation.

Human Reproduction: Sexual reproduction. Involves formation of gametes (sperm and ovum).

Gonads: Primary reproductive organs. Testes in males, ovaries in females.

Puberty: Age when reproductive organs become functional. Marked by secondary sexual characteristics.

Diagram Importance: Overview diagrams of male and female reproductive systems are essential for ICSE.

Testes: Primary male organs. Located in scrotum outside body (temperature regulation).

Structure: (1) Seminiferous tubules - sperm production, (2) Interstitial cells - testosterone production.

Sperm Production: Spermatogenesis in seminiferous tubules. Sperms stored in epididymis.

Duct System: (1) Vas deferens - carries sperm from epididymis, (2) Urethra - common passage for sperm and urine.

Accessory Glands: (1) Seminal vesicles - provide nutrients, (2) Prostate gland - activates sperm, (3) Cowper's glands - lubricates urethra.

Semen: Mixture of sperm and secretions from glands. Provides nutrition and motility to sperm.

External Genitals: Penis and scrotum.

Hormones: Testosterone - secondary sexual characteristics, sperm production.

Diagram Importance: Labeled diagram of male reproductive system showing all parts is crucial.

Ovaries: Primary female organs. Located in pelvic cavity. Produce ova and hormones.

Structure: (1) Ovarian follicles - contain ova, (2) Corpus luteum - after ovulation.

Fallopian Tubes: Carry ova from ovaries to uterus. Site of fertilization.

Uterus: Pear-shaped organ. Site of embryo development. Inner lining (endometrium) thickens during menstrual cycle.

Cervix: Lower part of uterus. Opens into vagina.

Vagina: Birth canal. Receives penis during copulation.

External Genitals: Vulva (labia, clitoris).

Mammary Glands: Produce milk after childbirth.

Hormones: Estrogen - female secondary characteristics, Progesterone - pregnancy maintenance.

Diagram Importance: Labeled diagram of female reproductive system is frequently asked.

Spermatogenesis: Sperm production in testes. Diploid spermatogonium → haploid sperm.

Oogenesis: Ovum production in ovaries. Diploid oogonium → haploid ovum.

Sperm Structure: Head (acrosome, nucleus), neck, middle piece (mitochondria), tail (movement).

Ovum Structure: Large cell with nucleus, cytoplasm, zona pellucida, corona radiata.

Difference: Sperm small and motile; Ovum large and non-motile.

Diagram Importance: Comparative diagrams of sperm and ovum are important.

Menstrual Cycle: Monthly cycle in females. Prepares uterus for pregnancy. Duration: 28 days.

Phases: (1) Menstrual phase (1-5 days) - shedding of endometrium, (2) Follicular phase (6-13 days) - follicle development, estrogen secretion, (3) Ovulatory phase (14th day) - ovulation, (4) Luteal phase (15-28 days) - corpus luteum, progesterone secretion.

Hormones: FSH (follicle development), LH (ovulation), Estrogen (endometrium thickening), Progesterone (endometrium maintenance).

Menstruation: If no pregnancy, corpus luteum degenerates, progesterone decreases, endometrium sheds.

Menopause: Cessation of menstrual cycle around 45-50 years.

Diagram Importance: Diagram of menstrual cycle showing hormone levels and phases is crucial.

Fertilization: Fusion of sperm and ovum in fallopian tube. Forms zygote (2n).

Implantation: Zygote divides → morula → blastocyst → implants in uterus wall.

Embryonic Development: Zygote → Embryo (8 weeks) → Fetus (9 months).

Placenta: Connection between mother and fetus. Provides nutrients, oxygen, removes waste.

Amniotic Fluid: Protects fetus, allows movement.

Gestation Period: 280 days (40 weeks) in humans.

Parturition: Process of childbirth. Induced by oxytocin.

Diagram Importance: Diagrams of fertilization, implantation, and placenta are important.

Sexually Transmitted Diseases (STDs): HIV/AIDS, Gonorrhea, Syphilis, Herpes. Prevention: Safe sex, vaccination (HPV).

Contraception: Methods to prevent pregnancy. Natural (rhythm), Barrier (condoms), Hormonal (pills), Surgical (vasectomy, tubectomy).

Infertility: Inability to conceive. Causes: hormonal imbalance, infections, lifestyle.

Assisted Reproductive Technologies: IVF, IUI, surrogacy.

Importance: Education, hygiene, regular checkups.

Population Explosion: Rapid increase in population. Causes problems like poverty, pollution, resource depletion.

Control Measures: Family planning, education, women's empowerment, government policies.

Methods: Contraception, delayed marriage, small family norm.

Government Programs: National Population Policy, awareness campaigns.