Search results
Results from the WOW.Com Content Network
Normal spermatogenesis, testis biopsy. High-power view of a seminiferous tubule with normal spermatogenesis. Spermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testicle. This process starts with the mitotic division of the stem cells located close to the basement membrane of ...
Spermiogenesis is the final stage of spermatogenesis, during which the spermatids develop into mature spermatozoa. At the beginning of the stage, the spermatid is a more or less circular cell containing a nucleus , Golgi apparatus , centriole and mitochondria ; by the end of the process, it has radically transformed into an elongated ...
The last step of spermatogenesis is spermiogenesis. During this process, the spermatids are transformed into spermatozoa, mature sperm. At this point, no other division occurs. The sperm is released from the Sertoli cells and transported to the epididymis through peristalsis. While in the epididymis, the sperm is stored and begins maturation.
The spermatogenesis process in mammals as a whole, involving cellular transformation, mitosis, and meiosis, has been well studied and documented from the 1950s to 1980s. However, during the 1990s and 2000s researchers have focused around increasing understanding of the regulation of spermatogenesis via genes, proteins, and signaling pathways ...
Sperm cells form during the process known as spermatogenesis, which in amniotes (reptiles and mammals) takes place in the seminiferous tubules of the testicles. [3] This process involves the production of several successive sperm cell precursors, starting with spermatogonia, which differentiate into spermatocytes.
Spermatogonial stem cells are the precursors to spermatozoa, which are produced through a series of differentiation steps. [4] This is the alternative SSC outcome to self-renewal. SSCs survive within microenvironments, termed niches, which provide extrinsic stimuli that drive stem cell differentiation or self-renewal. [24]
These cells do not directly participate in producing sperm, instead serving to maintain the supply of stem cells for spermatogenesis. Each type Ad spermatogonium divides to produce another type Ad spermatogonium, which can further carry on spermatogenesis, and one type Ap spermatogonium , which differentiates further.
The process of fertilization involves a sperm fusing with an ovum. The most common sequence begins with ejaculation during copulation , follows with ovulation , and finishes with fertilization. Various exceptions to this sequence are possible, including artificial insemination , in vitro fertilization , external ejaculation without copulation ...