Sperm, or spermatozoa, are male reproductive cells that fertilize the female egg (ovum) to create an embryo, leading to the development of a fetus.
Structure of Sperm:
Sperm cells have a specialized structure consisting of three main parts:
1. Head:
Contains the nucleus with genetic material (DNA) passed to the offspring.
Covered by the acrosome, a cap-like structure with enzymes to help the sperm penetrate the egg.
2. Midpiece:
Connects the head to the tail and houses mitochondria, providing energy for sperm movement.
3. Tail (flagellum):
A whip-like structure that propels the sperm, allowing it to swim through the female reproductive tract.
Sperm Production:
Sperm are produced in the seminiferous tubules within the testes through spermatogenesis:
Spermatogonia (precursor cells) undergo mitosis and meiosis to form mature sperm with half the chromosomes of normal body cells, ensuring correct chromosomal count after fertilization.
Maturation and Storage
After spermatogenesis, sperm move to the epididymis, a coiled tube where they mature and are stored until ejaculation.
Ejaculation and Fertilization:
During ejaculation, sperm are mixed with fluids from the seminal vesicles, prostate gland, and bulbourethral glands to form semen.
The sperm travel through the female reproductive tract, and if they reach the fallopian tubes where an ovum is present, they use acrosomal enzymes to penetrate the egg.
One sperm fuses with the ovum, combining their genetic material in a process called fertilization, resulting in a zygote that can develop into an embryo.