Spermatozoon, male germ cell, male gamete
Sperm is the male reproductive cell, which is able to fertilize the counterpart female gamete, the oocyte, during conception to produce a single-celled individual known as a zygote. Sperm are smaller than the most cells in the body. A uniflagellar sperm cell that is motile is referred to as a spermatozoon, whereas a non-motile sperm cell is referred to as a spermatium. Mature sperm cells cannot divide and they have a limited life span, but after fusion with egg cells during fertilization, a new organism forms, beginning as a totipotent zygote. The human sperm cell is haploid, so that its 23 chromosomes can join the 23 chromosomes of the female egg to form a diploid cell.
During fertilization, the sperm provides three essential parts to the oocyte:¨
The sperm cells travel through the seminiferous tubules to the epididymis (located above the testicle). The epididymis is responsible for storing the sperm cells until they mature. The sperm cells then travel through the vas deferens where they pick up fluid from the seminal vesicles, prostate gland, and Cowper’s gland. This fluid and sperm cells are known as semen. The purpose of the fluid is to allow the sperm to move, give them nutrients and provide a comfortable environment to survive.
Sperm has a distinctive head, mid-piece, and tail region (Pic.1):
Spermatogenesis is the process in which spermatozoa are produced from male primordial germ cells by way of mitosis and meiosis (Pic. 3). The process begins at puberty, after which time sperm are produced constantly throughout a man’s life. Sperms develop in the testicles. One production cycle, from spermatogonia through formed sperm (Tab. 1), takes approximately 64 days. The initial cells in this pathway are called spermatogonia, which yield primary spermatocytes by mitosis. The primary spermatocyte divides meiotically (Meiosis I) into two secondary spermatocytes; each secondary spermatocyte divides into two spermatids by meiosis II. These develop into mature spermatozoa, also known as sperm cells. Thus, the primary spermatocyte gives rise to two cells, the secondary spermatocytes, and the two secondary spermatocytes by their subdivision produce four spermatozoa.
The inability (that lasts more than 6 months) to develop or maintain an erection of the penis during sexual activity.
The pathological inability to ejaculate in males, with (orgasmic) or without (anorgasmic) orgasm.
A medical term which describes a diminished functional activity of the gonads – the testes and ovaries.
An inflammation of the prostate gland.
Absence of sperm in the ejaculate despite normal spermatogenesis, caused by an obstruction of the genital tract.
An inflammation of the testes, involving swelling and heavy pains.
Emergency medical condition occurring when the spermatic cord twists and cuts off the testicle's blood supply.
Teratospermia is a condition characterized by the presence of sperm with abnormal morphology that affects fertility in males.
Male infertility diagnosis characterized by extremely low concentration of sperm in semen.
The inability of the testicles to produce sperm or testosterone.
A family of genetic disorders caused by missing gene(s) in the Y chromosome.
The absence of any developmental stage of sperm cell in the testes.
Male gonads which produce both sperm and androgens, such as testosterone, and are active throughout the reproductive lifespan of the male.
The fusion of an ovum with a sperm to initiate the development of a new individual organism.