Spermatozoon (frequently shortened to 'sperm') are the male germ cells. In the lowest forms of life the spermatozoon and the female cell, or egg, are very similar, but in the higher forms the spermatozoon becomes a highly specialised active locomotor cell, and the female egg, or ovum, becomes a larger, more passive cell. The spermatozoon is provided with a head, body and tail, the head containing a nucleus of chromatin, the body the centrosome, and the tail is a cytoplasmic thread. The tail provides the cell with the power required for movement. Research Spermatozoon
The acrosome is a thin cap of protoplasm encasing the head of a sperm. The acrosome is believed to contain an enzyme, hyaluronidase, that dissolves the coronaradiata, the protective outer coat of the ovum, making sperm penetration easier. The enzyme of the acrosome of one sperm is insufficient to break down the ovummembrane. Therefore, contrary to popular opinion, it takes more than one spermatozoon to produce a baby. Only one sperm, however, will actually penetrate the egg. Research Acrosome
The female reproductive system is responsible for generating the ovum, or egg, for storing the fertilized ovum, and nourishing the gestating embryo and fetus. The chief organs include the ovaries, the uterus, vagina, and the fallopian tubes. External (vulvar) organs include the labia majora, the labia minora, the mons pubis, the clitoris, the vestibule, and the greater vestibular cleft. The ovum, or egg, contains the female's contribution to the genetic make-up of the new child, and is generated in the ovaries. The newly generated ovum is passed through the fimbriated extremity of a fallopian tube, into the fallopian tube and there is fertilized by a spermatozoon (a sperm cell). During sexual arousal, a fluid created by the male's seminal vesicles and the prostate gland combines with the sperm cells to create semen, which is carried through the urethra and out of the opening, or meatus, in the end of the erect penis.
When the semen is deposited in the female vagina, the spermatozoa swims through the uterus to the fallopian tube, where it fertilizes the ovum, or egg. The fertilized egg travels down the fallopian tube within the next three days and becomes attached to the wall of the uterus (womb). There, during pregnancy, the fertilized egg will be nourished and will develop into the embryo and, later, the fetus. Once fully developed (after about 9 months), muscular contractions (labor) will push the fetus out of the womb. Research Female Reproductive System
The fimbriated extremity is the fringe-like structure at the end of each fallopian tube. The newly generated ovum, or egg, enters this extremity to travel down the fallopian tube, where it will be fertilized by a spermatozoon. Research Fimbriated Extremity
Gametes are cells taking part in sexual reproduction. The female gamete is the ovum (egg-cell) and the male gamete of animals is the spermatozoon or sperm, and the male gamete of plants the spermatozoid. Research Gamete
The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
Abbreviations
Research Spermatozoon
