Spermatogenesis refers to the creation, or genesis, of sperm cells, which occurs in the male gonads or testes. Sperm cells develop initially from germ stem cells known as spermatogonia. As these differentiate they become spermatocytes, spermatids (after meiosis) and then finally the fully mature spermatozoa. The female counterpart to spermatogenesis is oogenesis. Schematic diagram of a sperm cell, showing the (1) acrosome, (2) cell membrane, (3) nucleus, (4) mitochondria, and (5) flagellum (tail) A sperm cell, or spermatozoon ( spermatozoa) (in Greek: sperm = semen and zoon = alive), is the haploid cell that is the male gamete. ... Male is the sex of an organism, or a part of an organism, which produces sperm. ... A sex organ, or primary sexual characteristic, narrowly defined, is any of those parts of the body (which are not always bodily organs according to the strict definition) which are involved in sexual reproduction and constitute the reproductive system in an complex organism; namely: Male: penis (notably the glans penis... Human male anatomy The testicles, known medically as testes (singular testis), are the male generative glands in animals. ... The introduction of this article does not provide enough context for readers unfamiliar with the subject. ... The term spermatid refers to the haploid male germ cell that results from secondary spermatocyte division. ... Overview of the major events in meiosis Meiosis (a Greek word meaning decrease) is a cellular process that forms the basis for sexual reproduction, together with syngamy. ... Female is the sex of an organism, or a part of an organism, which produces egg cells. ... Oogenesis refers to the process of formation, development, and maturation of a healthy oocyte (egg) in the ovary. ...

The process of spermatogenesis is highly regulated via hormonal messengers and also the cell-cell comunication between the developing germ cells (sperm cells) and the nurse-like Sertoli cells. The Sertoli cell is the nurse cell of the testes. ...

The Sertoli cell is essential for spermatogenesis as it provides support for the developing sperm cells - moving them towards the lumen of the semiferous tubule as they develop until maturity when they are released. The Sertoli cell also reduces motility and capacitation (initiation of the acrosome reaction) of the sperm cells so viability is maintained. The Sertoli cell is the nurse cell of the testes. ...

Spermatozoa are produced in seminiferous tubules in the testes. They start off as spermatogonia, undergoing mitosis becoming a type A spermatogonium or a type B spermatogonium. Type B spermatogonia become primary spermatocytes. Primary spermatocytes go through a meiotic division to become secondary spermatocytes, which undergo another meiotic division to become spermatids. Type A spermatogonia stay as spermatogonia, and do not change. They act as stem cells and will divide again producing more Type A and B cells. Human male anatomy The testicles, known medically as testes (singular testis), are the male generative glands in animals. ... The introduction of this article does not provide enough context for readers unfamiliar with the subject. ... Overview of the major events in mitosis In biology, mitosis is the process of chromosome segregation and nuclear division that follows replication of the genetic material in eukaryotic cells. ... Overview of the major events in meiosis Meiosis (a Greek word meaning decrease) is a cellular process that forms the basis for sexual reproduction, together with syngamy. ... The term spermatid refers to the haploid male germ cell that results from secondary spermatocyte division. ... Mouse embryonic stem cells. ...

The primary spermatocytes contain twice the DNA of a normal body cell (2 × 2N). Each primary spermatocyte divides into two secondary spermatocytes containing two sets of chromosomes (2 × 1N). The secondary spermatocytes then divide into two spermatids, each containing just one set of chromosomes (1N), half the DNA needed to make a human being. (The other half will come from the ovum at fertilisation). Space-filling model of a section of DNA molecule Deoxyribonucleic acid (DNA) or deoxyribose nucleic acid is a nucleic acid that contains the genetic instructions specifying the biological development of all cellular forms of life (and many viruses). ... Figure 1: Chromosome. ... A human ovum An ovum (also oocyte, ovocyte, or loosely, egg or egg cell) is a female sex cell or gamete. ...

The spermatids at this point are still round cells. During the process called spermiogenesis the sperm extrude tails, repackage DNA into a head, cap the head with a lysosome-like acrosome and construct an energy transducing neck region of tightly packed mitochondria to finally become mature testicular spermatozoa. They are then released into the lumen of the seminiferous tubule and travel with fluid from the testis into the epididymis for further maturation processes allowing them to swim forward and fertilize an ovum. In sperm cells of many higher animals, the acrosome develops over the anterior half of its head. ... In cell biology, a mitochondrion is an organelle found in the cells of most eukaryotes. ... Male Anatomy The epididymis is part of the human male reproductive system and is present in all mammals. ...