The Human Reproductive System (CSEC HSB 2024/2025 Syllabus)

Introduction to Reproduction

Reproduction is the biological process by which organisms produce offspring. In humans, this involves specialized systems that differ between males and females. The reproductive system develops during puberty under hormonal control.

Male Reproductive System

Testes Epididymis Vas Deferens Prostate Penis

Figure 1: Male Reproductive System

Key Structures and Functions:

Female Reproductive System

Ovary Fallopian Tube Uterus Vagina

Figure 2: Female Reproductive System

Key Structures and Functions:

Gamete Production

Feature Spermatogenesis (Male) Oogenesis (Female)
Location Seminiferous tubules in testes Ovarian follicles
Duration Continuous after puberty (~74 days per cycle) Cyclical (28 days per menstrual cycle)
Result per meiosis 4 viable sperm 1 ovum + 3 polar bodies
Lifespan of gametes ~5 days in female tract 12-24 hours after ovulation

The Menstrual Cycle (28 Days)

Menstrual Phase (1-5) Follicular Phase (6-13) Ovulation (14) Luteal Phase (15-28) Estrogen Progesterone

Figure 3: Menstrual Cycle Phases and Hormones

Key Events:

Fertilization and Early Development

Fallopian Tube Sperm Ovum Zygote

Figure 4: Fertilization Process

Contraceptive Methods

Method Type Mechanism Effectiveness
Condom Barrier Blocks sperm entry 85-98%
Oral Contraceptive Hormonal Prevents ovulation 91-99%
IUD Intrauterine Prevents implantation 99%
Vasectomy Surgical Blocks vas deferens 99.9%

Glossary of Key Terms

Gamete
Reproductive cell (sperm or ovum) with haploid chromosome number (23)
Zygote
Fertilized egg with diploid chromosome number (46)
Menarche
First menstrual period in females (typically age 11-14)
Placenta
Organ that nourishes fetus and removes wastes during pregnancy
Puberty
Developmental stage when reproductive systems become functional
Testosterone
Primary male sex hormone responsible for secondary sexual characteristics
Estrogen
Primary female sex hormone that regulates menstrual cycle

Self-Assessment Questions

1. Name the male reproductive organ that produces both sperm and testosterone.

Testes

2. Where in the female reproductive system does fertilization typically occur?

Fallopian tube

3. What is the name of the process by which sperm are produced?

Spermatogenesis

4. Which hormone, produced by the corpus luteum, maintains the uterine lining during pregnancy?

Progesterone

5. What is the term for the release of a mature ovum from the ovary?

Ovulation

6. List two barriers to sperm entry used in contraception.

Condoms and diaphragms

7. What structure connects the fetus to the placenta during pregnancy?

Umbilical cord

8. During which phase of the menstrual cycle does menstruation occur?

Menstrual phase (days 1-5)

9. What is the function of the prostate gland in the male reproductive system?

Produces alkaline fluid that forms part of semen

10. How many chromosomes are present in a human gamete?

23 (haploid number)