Class 12 Notes

Class 12 Biology Notes Chapter 4 (Reproductive health) – Biology Book

Philoid

Philoid

— 7 min read

Biology
Detailed Notes with MCQs of Chapter 4: Reproductive Health. This is a crucial chapter, not just for your exams but for life. Understanding reproductive health is vital for building a healthy society. Pay close attention as we break down the key concepts for your government exam preparation.

Chapter 4: Reproductive Health - Detailed Notes

1. Introduction to Reproductive Health

  • Definition (WHO): Reproductive health means total well-being in all aspects of reproduction, i.e., physical, emotional, behavioural, and social. It's not merely the absence of disease or infirmity related to the reproductive system.
  • Significance: A society with reproductively healthy individuals has fewer health problems, reduced maternal and infant mortality, better family planning, and overall improved quality of life.
  • India's Initiatives: India was among the first countries globally to initiate national-level action plans and programs ('Family Planning' in 1951) to attain total reproductive health as a social goal. These are periodically assessed and improved.

2. Reproductive Health - Problems and Strategies

  • Major Problems:
    • Lack of awareness about reproductive processes, hygiene, STIs, and contraception.
    • Myths and misconceptions surrounding reproductive health.
    • Inadequate medical facilities and support for reproductive health issues, especially in rural areas.
    • Rapid population growth leading to resource scarcity.
    • Social evils like sex abuse and sex-related crimes.
    • Increasing incidence of STIs.
  • Strategies & Programs:
    • Reproductive and Child Health (RCH) Programs: Launched to create awareness among people about various reproduction-related aspects and provide facilities and support for building up a reproductively healthy society.
    • Goals of RCH:
      • Creating awareness about hygiene, STIs, available contraceptive options, care for pregnant mothers, post-natal care, importance of breastfeeding, etc.
      • Providing medical facilities for pregnancy, delivery, STIs, abortion, contraception, menstrual problems, infertility, etc.
      • Building better infrastructure and professional expertise.
    • Role of Education: Introduction of sex education in schools to provide right information, discourage myths, and promote responsible sexual behaviour.
    • Role of Media & NGOs: Audio-visual and print media, along with governmental and non-governmental agencies (NGOs), play a significant role in creating awareness.
    • Statutory Ban: Amniocentesis (a foetal sex determination test based on chromosomal pattern in amniotic fluid) is banned for sex determination to prevent female foeticide, though it's valuable for detecting certain genetic disorders.

3. Population Explosion and Birth Control

  • Population Explosion: The rapid increase in population size over a relatively short period.
    • Reasons in India:
      • Rapid decline in death rate.
      • Decline in Maternal Mortality Rate (MMR).
      • Decline in Infant Mortality Rate (IMR).
      • Increase in the number of people in the reproducible age group.
      • Better healthcare facilities leading to increased longevity.
    • Consequences: Scarcity of basic requirements (food, shelter, clothing), strain on infrastructure and resources.
    • Control Measures: Motivating smaller families using contraceptive methods, raising marriageable age (females: 18 yrs, males: 21 yrs), providing incentives to couples with small families.
  • Contraceptive Methods: Methods used to prevent unwanted pregnancies.
    • Properties of an Ideal Contraceptive: User-friendly, easily available, effective, reversible (or permanent if desired), no or least side-effects, should not interfere with sexual drive/act.
    • Types of Contraceptive Methods:
      • a) Natural/Traditional Methods: Work on the principle of avoiding chances of ovum and sperm meeting.
        • Periodic Abstinence (Rhythm Method): Avoiding coitus from day 10 to 17 of the menstrual cycle (fertile period). High failure rate.
        • Coitus Interruptus (Withdrawal): Withdrawing the penis from the vagina just before ejaculation. High failure rate.
        • Lactational Amenorrhea (LAM): Absence of menstruation during intense lactation following parturition. Ovulation does not occur. Effective only up to a maximum of six months post-partum. High failure rate.
      • b) Barrier Methods: Prevent physical meeting of sperm and ovum.
        • Condoms: Barriers made of thin rubber/latex sheath used to cover the penis (male) or vagina/cervix (female) just before coitus. Prevent semen deposition into the female reproductive tract. Advantage: Protects against STIs and AIDS. Disposable.
        • Diaphragms, Cervical Caps, Vaults: Rubber barriers inserted into the female reproductive tract to cover the cervix during coitus. Reusable. Spermicidal creams/jellies enhance efficiency.
      • c) Intra Uterine Devices (IUDs): Devices inserted by doctors/expert nurses into the uterus through the vagina. Most widely accepted method in India.
        • Non-medicated IUDs: E.g., Lippes loop. Increase phagocytosis of sperms within the uterus.
        • Copper releasing IUDs: E.g., CuT, Cu7, Multiload 375. Release copper ions which suppress sperm motility and fertilizing capacity.
        • Hormone releasing IUDs: E.g., Progestasert, LNG-20. Make the uterus unsuitable for implantation and the cervix hostile to sperms.
      • d) Oral Contraceptives (Pills): Contain progestogens alone or in combination with estrogen.
        • Mechanism: Inhibit ovulation and implantation; alter the quality of cervical mucus to prevent sperm entry.
        • Usage: Taken daily for 21 days, starting within the first 5 days of the menstrual cycle, followed by a 7-day gap. Very effective, lesser side effects.
        • 'Saheli': Developed by CDRI, Lucknow. A non-steroidal preparation, taken once a week. High contraceptive value, very few side effects.
      • e) Injectables and Implants: Progestogens alone or with estrogen. Administered as injections or implants under the skin.
        • Mechanism: Similar to pills but effective for longer periods.
      • f) Emergency Contraceptives: Administration of progestogens or progestogen-estrogen combinations or IUDs within 72 hours of unprotected coitus. Used to avoid possible pregnancy due to rape or casual unprotected intercourse.
      • g) Surgical Methods (Sterilization): Terminal methods, block gamete transport. Highly effective but poor reversibility.
        • Vasectomy (Males): A small part of the vas deferens is removed or tied up through a small incision on the scrotum. Prevents sperm transport.
        • Tubectomy (Females): A small part of the fallopian tube is removed or tied up through an incision in the abdomen or through the vagina. Prevents ovum transport and fertilization.

4. Medical Termination of Pregnancy (MTP)

  • Definition: Intentional or voluntary termination of pregnancy before full term. Also called induced abortion.
  • Legal Status: Legalized in India by the Medical Termination of Pregnancy (MTP) Act, 1971, with strict conditions to avoid misuse (like female foeticide). Recent amendments (e.g., MTP Amendment Act 2021) have updated gestation limits and conditions.
  • Indications for Legal MTP:
    • To prevent pregnancy resulting from rape or contraceptive failure.
    • When continuation of pregnancy is harmful/fatal to the mother or the foetus.
  • Safety: Relatively safe during the first trimester (up to 12 weeks). Second trimester abortions are much riskier.
  • Misuse: Often misused for illegal female foeticide, which is detrimental to society. Effective counselling is needed to prevent misuse.

5. Sexually Transmitted Infections (STIs)

  • Definition: Infections or diseases transmitted through sexual intercourse. Also known as Venereal Diseases (VD) or Reproductive Tract Infections (RTI).
  • Common STIs & Causative Agents:
    • Gonorrhoea - Neisseria gonorrhoeae (Bacteria)
    • Syphilis - Treponema pallidum (Bacteria)
    • Genital Herpes - Herpes simplex virus (Virus)
    • Chlamydiasis - Chlamydia trachomatis (Bacteria)
    • Genital Warts - Human papillomavirus (Virus)
    • Trichomoniasis - Trichomonas vaginalis (Protozoan)
    • Hepatitis-B - Hepatitis B virus (HBV) (Virus)
    • AIDS - Human Immunodeficiency Virus (HIV) (Virus)
  • Mode of Transmission:
    • Sexual contact with infected person.
    • Sharing of injection needles, surgical instruments.
    • Transfusion of infected blood.
    • From infected mother to foetus (except for Genital Herpes, HIV, Hepatitis-B, others are generally curable if detected early).
  • Symptoms: Often minor or absent (asymptomatic) initially, especially in females. Early symptoms include itching, fluid discharge, slight pain, swelling in the genital region.
  • Complications if Untreated: Pelvic Inflammatory Diseases (PID), abortions, still births, ectopic pregnancies, infertility, cancer of the reproductive tract.
  • Prevention:
    • Avoid sex with unknown/multiple partners.
    • Always use condoms during coitus.
    • Consult a qualified doctor for early detection and complete treatment if symptoms appear.
  • Vulnerable Age Group: 15-24 years.

6. Infertility

  • Definition: Inability to conceive or produce children even after 2 years (or commonly defined as 1 year) of unprotected sexual cohabitation.
  • Causes: Can be due to problems in the male or female partner. Include physical, congenital, diseases, drugs, immunological, or even psychological factors.
  • Diagnosis & Treatment: Specialized health care units (infertility clinics) help in diagnosis and corrective treatment.
  • Assisted Reproductive Technologies (ART): Technologies used to achieve pregnancy when natural conception fails.
    • a) In Vitro Fertilization (IVF) - Embryo Transfer (ET): 'Test Tube Baby' program. Ova from wife/donor and sperm from husband/donor are collected and induced to fertilize in vitro (outside the body, in laboratory conditions). The resulting zygote or early embryo (up to 8 blastomeres) is transferred into the fallopian tube (ZIFT - Zygote Intrafallopian Transfer) or embryos with more than 8 blastomeres are transferred into the uterus (IUT - Intra Uterine Transfer).
    • b) Gamete Intrafallopian Transfer (GIFT): Transfer of an ovum collected from a donor into the fallopian tube of another female who cannot produce ova but can provide a suitable environment for fertilization and development. Fertilization occurs in vivo (inside the body).
    • c) Intracytoplasmic Sperm Injection (ICSI): A specialized IVF procedure where a single sperm is directly injected into the cytoplasm of an ovum in the laboratory. Used mainly for severe male infertility.
    • d) Artificial Insemination (AI): Semen collected from the husband or a healthy donor is artificially introduced into the vagina or uterus (IUI - Intra-Uterine Insemination) of the female. Used in cases where the male partner has low sperm count or inability to inseminate.
  • Limitations: ART procedures require highly specialized professionals, expensive instrumentation, and can be emotionally taxing.
  • Adoption: A legal and often fulfilling option for couples unable to conceive.

Multiple Choice Questions (MCQs)

  1. According to WHO, reproductive health encompasses well-being in which aspects?
    (a) Physical and Social only
    (b) Physical, Emotional, and Behavioural only
    (c) Physical, Emotional, Behavioural, and Social
    (d) Absence of reproductive diseases only

  2. Which of the following is NOT a goal of the Reproductive and Child Health (RCH) programs in India?
    (a) Creating awareness about contraception and STIs
    (b) Providing facilities for safe deliveries and post-natal care
    (c) Enforcing a strict two-child norm through legislation
    (d) Building better healthcare infrastructure for reproductive health

  3. Copper releasing IUDs, like CuT, primarily prevent pregnancy by:
    (a) Inhibiting ovulation
    (b) Making the uterus unsuitable for implantation
    (c) Suppressing sperm motility and fertilizing capacity
    (d) Blocking the cervix to prevent sperm entry

  4. 'Saheli', an oral contraceptive developed by CDRI, Lucknow, is unique because it is:
    (a) A combination of estrogen and progestogen
    (b) A once-a-week, non-steroidal pill
    (c) An emergency contraceptive pill
    (d) An injectable contraceptive

  5. The surgical sterilization method performed on males, involving cutting and tying the vas deferens, is called:
    (a) Tubectomy
    (b) Oophorectomy
    (c) Hysterectomy
    (d) Vasectomy

  6. Medical Termination of Pregnancy (MTP) is considered relatively safe during:
    (a) The first trimester (up to 12 weeks)
    (b) The second trimester (up to 24 weeks)
    (c) The third trimester
    (d) Any time before parturition

  7. Which of the following STIs is caused by a protozoan?
    (a) Syphilis
    (b) Genital Herpes
    (c) Trichomoniasis
    (d) Chlamydiasis

  8. Which practice offers significant protection against acquiring Sexually Transmitted Infections (STIs), including HIV/AIDS?
    (a) Periodic abstinence
    (b) Use of IUDs
    (c) Use of condoms during coitus
    (d) Lactational Amenorrhea

  9. Gamete Intrafallopian Transfer (GIFT) is recommended for females who:
    (a) Cannot produce ova but can provide a suitable environment for fertilization.
    (b) Can produce ova but cannot retain the foetus inside the uterus.
    (c) Have blocked fallopian tubes.
    (d) Suffer from severe uterine fibroids.

  10. The ART technique where a sperm is directly injected into the ovum in a laboratory setting is known as:
    (a) IVF (In Vitro Fertilization)
    (b) ZIFT (Zygote Intrafallopian Transfer)
    (c) AI (Artificial Insemination)
    (d) ICSI (Intracytoplasmic Sperm Injection)

Answer Key for MCQs:

  1. (c)
  2. (c)
  3. (c)
  4. (b)
  5. (d)
  6. (a)
  7. (c)
  8. (c)
  9. (a)
  10. (d)

Study these notes thoroughly. Remember the full forms, mechanisms of contraceptives, causative agents of STIs, and the basic principles of ARTs. These are frequently tested areas. Good luck with your preparation!

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