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sperm, male reproductive cell, produced by most animals. With the exception of nematode worms, decapods (e.g., crayfish), diplopods (e.g., millipedes), and mites, sperm are flagellated; that is, they have a whiplike tail. In higher vertebrates, especially mammals, sperm are produced in the testes. The sperm unites with ( fertilizes) an ovum ...
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Key Points. Spermatogenesis begins with a diploid spermatogonium in the seminiferous tubules, which divides mitotically to produce two diploid primary …
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Spermatogenesis is the production of sperm from the primordial germ cells within the male reproductive organs, the testes. The process of spermatogenesis occurs in the epithelium of the seminiferous tubules, with the spermatogonia and the spermatozoa at the lumen of the border of the tubule. Within the walls, there are cells called the Sertoli ...
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The buffer was also used to successfully freeze human spermatozoa [108, 109]. In early attempts to achieve fertilization in vitro in hamster, Bavister examined the use Tris-Citrate buffer (25 mM). Though an excellent pH buffer, and despite the fact that it stimulated sperm motility, no fertilization was obtained from 207 oocytes inseminated
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Human spermatozoa (2 C, 20 F) T. Transgender (Eiaculatio) (3 F) Media in category "Human semen" The following 58 files are in this category, out of 58 total. 0030Sperm under a microscope.webm 21 s, 544 × 960; 3.14 . 01 MySperma.jpg 2,736 × 3,648; 1.25 . 01 Sperma.jpg 1,800 × 1,203; 497 KB.
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Abstract. A spermatozoon is a male germ cell capable of fertilizing an oocyte and carries genetic information for determining the of the offspring. It comprises autosomes and an X (X spermatozoa) or a Y chromosome (Y spermatozoa). The origin and maturation of both X and Y spermatozoa are the same, however, certain …
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The habit of closing the opening of the urethra at the end of masturbation, which prevents full ejaculation. Defects of the seminiferous ducts of congenital origin. The condition is aggravated by depression, psycho-emotional disorders, sperm stagnation, denial of sexual life, and impotence. spermatozoa in urine.
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The number of spermatozoa detected was analyzed at three dif-ferent time intervals since intercourse (Fig. 4). We observed that: (i) no spermatozoa were detected after 72 h with any stain; (ii) dur-ing the first 72 h, there was no significant difference between the two most efficient tests: 15.1 spermatozoa per microscopic field for
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Because grinding often occurs fully dressed, and in underwear, chances are low that the ejaculate and sperm enter the vagina. Getting pregnant while grinding …
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A woman can't get pregnant this way. Pregnancy is possible whenever sperm get in a woman's vagina. This may happen during vaginal intercourse, but it may …
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Spermatozoa are the mature male gametes in many sexually reproducing organisms. Spermatogenesis is the male version of gametogenesis and results in the formation of spermatocytes possessing half the normal complement of genetic material. In mammals, it occurs in the male testes and epididymis in a stepwise fashion that takes …
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Spermatozoon definition: The male germ cell, found in semen, which penetrates the ovum, or egg, of the to fertilize it: typically it consists of a head containing a large nucleus, a small midsection, and a whiplike tail used for locomotion.
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2 ). According to the most recent World Health Organisation (WHO) guidelines, even in normal, fertile men, up to 96% of the spermatozoa will be abnormally formed, up to 68% will be immotile and up to 42% will be dead [ 6 ]. The only other primate to exhibit such poor quality semen is our close relative the gorilla, suggesting that the …
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spermatozoon: [noun] a motile male gamete of an animal usually with rounded or elongate head and a long posterior flagellum.
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The spermatozoa have to go through several temporal maturation steps in a series of different locations in order to be capable of penetrating into the oocyte. While the oocyte's maturation steps involve the storing of yolk and the process of meiosis, functional maturation steps are required with the spermatozoa, which mainly involve their motile …
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The construction of a database to hold information obtained from the laboratory analysis of items in cases of sexual assault is described. Examples of the usefulness of the database are described. For vaginal, anal and oral swabs, the persistence of spermatozoa in relation to time since intercourse is presented and discussed.
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The term spermatozoa (singular: spermatozoon), also known as sperm, refers to the male cells or gametes. They are formed through the process of spermatogenesis, which begins at puberty with the proliferation progenitor (stem) cells …
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Key Terms. anisogamy: The form of sexual reproduction that involves the union or fusion of two gametes that differ in size and/or form.; spermatozoa: A motile sperm cell or moving form of the haploid cell that is the male gamete.; acrosome: A caplike structure over the anterior half of the sperm's head.; ATP: An acronym for adenosine …
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Roles of Small Ubiquitin-Related Modifiers in Male Reproductive Function. Margarita Vigodner, in International Review of Cell and Molecular Biology, 2011. 3.3 SUMO during spermiogenesis. Meiosis results in the production of round haploid spermatids, which undergo further differentiation to become mature spermatozoa.The process is called …
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53) Contraction of the cremaster muscles. A) tenses the scrotal sac. B) pulls the testes closer to the body cavity. C) propels sperm through the urethra. D) moves sperm through the ductus deferens. E) tenses the scrotal sac and pulls the testes closer to the body cavity. E) tenses the scrotal sac and pulls the testes closer to the body cavity.
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The spermatozoa or sperm has an expanded head, narrow neck, and a long principal tail. Again, you will see three pieces in the tail – middle, principal, and end under the electron microscope. So, if you want to identify and learn the detailed histology of sperm under a microscope, let's continue this article till the end. Don't forget to ...
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Sorted spermatozoa were more prone to undergo acrosome reaction (P<0.05), at the beginning and after 1.5h and 3h of incubation, and also had higher tyrosine phosphorylation of the tail (P<0.001), only at the beginning of the incubation period. Apparently sorted stallion spermatozoa are in a more advanced status of membrane destabilization ...
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Spermatogenesis at a glance. Spermatogenesis is the process by which male gametes develop from germ cells in the testes. In other words, it's how sperm is made. This process involves multiple steps of cell division and differentiation, which are summarized in …
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The effects of semen extender components on the ability of stallion sperm to bind to the zona pellucida (ZP) and the suitability of using bovine ZP for a ZP-binding assay for stallion sperm were investigated in a series of experiments. In Experiment I, binding of stallion sperm to both bovine and eq …
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Introduction. The glands involved in the ejaculation. The seminal plasma. The spermatozoa. Processes in the male genital tract. The supplying of the spermatozoa …
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The spermatozoa. Looking at a spermatozoon one distinguishes: The head contains the condensed nucleus, which is covered on the top by an acrosome, a cap-like vesicle. Hydrolyzing enzymes that play an important role in the penetration of the protective coverings of the oocyte (corona radiata and pellucid zone) are stored in the vesicle. The ...
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The meaning of SPERMATOZOON is a motile male gamete of an animal usually with rounded or elongate head and a long posterior flagellum.
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Single human spermatozoa [1] This page introduces spermatogenesis the development of spermatozoa, the male haploid gamete cell. In humans at puberty, spermatozoa are produced by spermatogonia meiosis in the seminiferous tubules of the testis (male gonad). A second process of spermiogenesis leads to change in cellular …
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2.1 Anatomy of the Epididymis and Sperm Transport. Together with secretions from the Sertoli cells, spermatozoa are flushed from the seminiferous tubules through the recti tubuli into the cavities of the rete testis and enter the 12–18 efferent ducts by absorption pressure. Each efferent duct is 0.2–0.5 m long, and together they form the …
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Antonie van Leeuwenhoek, detail of a portrait by Jan Verkolje; in the Rijksmuseum, Amsterdam. Antonie van Leeuwenhoek, (born Oct. 24, 1632, Delft, Neth.—died Aug. 26, 1723, Delft), Dutch microscopist. In his youth he was apprenticed to a draper; a later civil position allowed him to devote time to his hobby: grinding lenses and using them to ...
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Introduction. Mammalian spermatozoa change their flagellar movement during hyperactivation. Hyperactivated motility is essential for mammalian spermatozoa to reach and fertilize the egg 1) and is characterized by large bends at the proximal midpiece and low beat frequency. 2–5) Detailed analyses of hyperactivated flagellar movement …
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General Principles. There are numerous protocols employed for selection of spermatozoa from a given semen sample. Since final harvest of spermatozoa is low from many such protocols, we have described only three simple sperm preparation protocols for sperm selection, viz., simple sperm washing, direct swim-up, and density-gradient …
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Most of the sperm dry preservation research conducted to date has been centered on mouse spermatozoa, with only a small number of studies in nonrodent mammalian species, as summarized in Table 1. Bhowmick et al. reported fetal mouse production using forced convective drying of mouse spermatozoa to an end moisture …
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Binding efficiency ranged from 6.3% (Nakanishi and Iritani, 1993) to 25% (Castro et al., 1991) of spermatozoa incubated with exogenous DNA, with most sperm cells showing DNA molecules bound to the whole head or to its posterior region. The internalization of exogenous DNA was suggested by the persistence of label. after.
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