Cellular Division and Human Reproductive Systems

Cellular Division: Meiosis and Mitosis

Meiosis has two rounds of genetic separation and cellular division, while mitosis only has one of each.

Key Differences

• Meiosis: Homologous chromosomes separate, leading to daughter cells that are not genetically identical.
• Mitosis: The daughter cells are genetically identical to the parent cell, as well as to each other.

Male Reproductive System

Primary Sex Organs

A pair of testes (singular: testis) lying outside the abdominal cavity, enclosed in a sac called the scrotum.

Secondary Sex Organs and Accessory Structures

Seminiferous Tubules

These tubules unite to form a long, coiled structure called the epididymis. They are involved in sperm production.

Epididymis

A long, coiled structure that acts as the main storage site for sperm. It leads into the muscular tube called the vas deferens.

Sperm Duct (Vas Deferens)

A muscular tube that opens on top of the urethra.

Seminal Vesicles

Branches from each sperm duct just above its opening into the urethra. They contribute fluid to semen.

Prostate Gland & Bulbourethral Gland (Cowper's Gland)

These are accessory glands connected to the urethra. They secrete alkaline fluid which helps neutralize the acidic environment and prevents sperm from sticking to each other.

Female Reproductive System

Primary Sex Organs: Ovaries

The primary sex organs consist of a pair of ovaries, which are oval bodies lying at the back of the abdomen below the kidney. Each ovary consists of many ovarian follicles, and each follicle can produce an egg (ovum).

Secondary Sex Organs

Fallopian Tubes (Oviducts)

After ovulation, the ovum or egg enters the fallopian tube to be carried along the passage toward the uterus.

Uterus

A hollow, thick-walled muscular organ. The main function of the uterus is to receive the fertilized ovum and nourish it until it attains full development.

Vagina

The muscular tube leading from the external genitals to the cervix of the uterus in women and most female mammals.

Key Sex Hormones

Testosterone

Testosterone is the primary male sex hormone and an anabolic steroid. In human males, it plays a key role in the development of male reproductive tissues (such as the testes and prostate) and promotes secondary sexual characteristics, including increased muscle and bone mass and the growth of body hair.

Estrogens

Estrogens are hormones that are important for sexual and reproductive development, primarily in women.