Sperm Formation and Pregnancy

Sperm Formation

The production of male gametes or sperm takes place in the testes; this process is known as spermatogenesis.
Sperm development starts from spermatogonia, which are undifferentiated cells that undergo mitosis (cell division).
The spermatogonia first become primary spermatocytes, which then undergo meiosis to form secondary spermatocytes, and eventually, they mature into spermatids and finally spermatozoa or sperm.
Each sperm cell consists of a head, middle piece, and a tail. The head contains genetic material, the middle piece is packed with mitochondria for energy, and the tail helps propel the sperm towards the egg.
Hormones play a vital role in controlling this process: testosterone is responsible for the physical changes like growth of body hair, deepening of the voice, and muscle development, while luteinising hormone (LH) stimulates the testes to produce testosterone.

Pregnancy

Pregnancy occurs when a sperm cell fertilizes an ovum in the fallopian tube; this combined cell is called a zygote.
The zygote undergoes several rounds of cell division, forming a ball of cells termed a blastocyst.
The blastocyst moves down the fallopian tube towards the uterus, where it implants in the uterine wall, marking the beginning of pregnancy.
Over the course of pregnancy, the blastocyst matures into an embryo, which ultimately develops into a fetus.
Various hormones including human chorionic gonadotropin (hCG), progesterone, and oestrogen play vital roles in maintaining a healthy pregnancy.
hCG signals to the corpus luteum (a structure in the ovary) to continue producing progesterone, which helps maintain the uterine lining for implantation.
Pregnancy is split into three trimesters, each with unique stages of fetal development.
By the end of the third trimester, the fetus is fully developed and ready for birth. Labor is initiated by hormonal signals, beginning the process of childbirth.