THE HUMAN REPRODUCTIVE SYSTEM
Grade 8 Science
Sources: Khan Academy, Britannica Kids, NIH
By: Maria Johanna B. Testa
OVERVIEW OF HUMAN REPRODUCTION
- Reproduction is the biological process by which new individual organisms are produced.
- Humans reproduce sexually, involving the fusion of male and female gametes.
- Two main systems: Male and Female Reproductive Systems.
MALE REPRODUCTIVE SYSTEM
Primary role: to produce and deliver sperm.
Main organs:
- Penis: Delivers sperm to the female reproductive tract.
- Testes: Produce sperm and testosterone.
- Scrotum: Protects and regulates temperature of testes.
- Vas deferens and urethra: Transport sperm.
FEMALE REPRODUCTIVE SYSTEM
Primary role: to produce eggs, provide site for fertilization and support fetal development.
Main organs:
- Ovaries: Produce eggs and female hormones.
- Fallopian tubes: Transport eggs; site of fertilization.
- Uterus: Supports development of the fetus.
- Vagina: Birth canal and receives sperm.
PUBERTY AND HORMONES
Puberty triggers the development of reproductive capabilities.
Controlled by hormones:
- Testosterone (males): Develops secondary sexual characteristics.
- Estrogen & Progesterone (females): Regulate menstrual cycle and reproductive functions.
Changes include voice deepening, breast development, and hair growth.
FERTILIZATION AND DEVELOPMENT
Fertilization: Union of sperm and egg in the fallopian tube.
Zygote forms, divides, and implants in uterus.
Stages: Zygote → Embryo → Fetus.
Pregnancy lasts around 9 months.
THE MENSTRUAL CYCLE
Occurs in females, typically every 28 days.
Prepares the body for possible pregnancy.
Phases:
- Menstrual phase: Shedding of uterine lining.
- Follicular phase: Egg development.
- Ovulation: Release of egg.
- Luteal phase: Prepares for implantation.
SUMMARY
- The reproductive system ensures the continuation of life.
- It involves complex organs and hormones working together.
- Understanding the system helps promote health and responsible choices.
REFERENCES
Khan Academy: www.khanacademy.org
Britannica Kids: kids.britannica.com
National Institutes of Health (NIH): www.nih.gov
Wikimedia Commons for public domain images