The seminal plasma provides a nutritive and protective medium for the spermatozoa during their journey through the female reproductive tract. Seminal plasma of humans contains a complex range of organic and inorganic constituents. The accessory genital ducts, the seminal vesicle, prostate glands, and the bulbourethral glands, produce most of the seminal fluid. Once the semen enters the ductus epididymis the principal cells, which contain pinocytotic vessels indicating fluid reabsorption, secrete glycerophosphocholine which most likely inhibits premature capacitation. The ductuli efferentes possess cuboidal cells with microvilli and lysosomal granules that modify the ductal fluid by reabsorbing some fluid. Sertoli cells, which nurture and support developing spermatocytes, secrete a fluid into seminiferous tubules that helps transport sperm to the genital ducts.
The bulbourethral glands secrete a clear secretion into the lumen of the urethra to lubricate it. The prostatic secretion, influenced by dihydrotestosterone, is a whitish (sometimes clear), thin fluid containing proteolytic enzymes, citric acid, acid phosphatase and lipids. The seminal vesicles produce a yellowish viscous fluid rich in fructose and other substances that makes up about 70% of human semen. Human Compositionĭuring the process of ejaculation, sperm passes through the ejaculatory ducts and mixes with fluids from the seminal vesicles, the prostate, and the bulbourethral glands to form the semen. In marsupial and placental mammals, copulation occurs through the vagina. In most vertebrates, including amphibians, reptiles, birds and monotreme mammals, copulation is achieved through the physical mating of the cloaca of the male and female. Internal fertilization takes place after insemination of a female by a male through copulation. Female fish, for example, spawn ova into their aquatic environment, where they are fertilized by the semen of the male fish.ĭuring internal fertilization, however, fertilization occurs inside the female's sexual organs. In external fertilization, the spermatozoa fertilize the ova directly, outside of the female's sexual organs. Cryoconservation of animal genetic resources is a practice that calls for the collection of genetic material in efforts for conservation of a particular breed.ĭepending on the species, spermatozoa can fertilize ova externally or internally. In animals, semen has been collected for cryoconservation. Semen is also a form of genetic material.
The fluid is designed to be discharged deep into the vagina, so the spermatozoa can pass into the uterus and form a zygote with an egg. In humans, seminal fluid contains several components besides spermatozoa: proteolytic and other enzymes as well as fructose are elements of seminal fluid which promote the survival of spermatozoa, and provide a medium through which they can move or "swim". The process that results in the discharge of semen from the urethral orifice is called ejaculation.
Semen is produced and originates from the seminal vesicle, which is located in the pelvis. It is secreted by the gonads (sexual glands) and other sexual organs of male or hermaphroditic animals and can fertilize the female ovum. Semen, also known as seminal fluid, is an organic bodily fluid created to contain spermatozoa. Spermatozoa, in this case human, are a primary component in normal semen, and the agents of fertilization of female ova.