How did the testis produce the sperm

How did the testis produce the sperm
If you have an opportunity to see the sperm under the microscope, you are sure to send out saying with feeling. Close and numerous sperm, the sample looks like tadpoles very much, the head is very small (6 microns long) ,But the tail is very long (60 microns) . It is this long tail that enables sperm to do all one can to swim forward and move, go to look for the ovum, and bind with it. However, the sperm activity stands up very fast. If you have an opportunity to see the sperm pierces into the scene of the ovum, several hundred sperms stick to the head the ovum (150 microns) much bigger than it in unison Have, the tail is swung desperately outwards, while doing all one can to bore inwards, you can be extremely surprised! Because of the sports of the sperm, embryonated egg and other sperms around turn rapidly, not stopping rotating, they seem to be dancing dance of the life.
You are sure to ask, why produced the sperm on earth to see these excellent scenes, why the volume of the testis is so small, could produce more than one hundred million sperms unexpectedly every day? If you want to answer this question, must talk about from dissection shape and institutional framework of the testis.
The testis is a male gonad, the place of producing sperms and secreting sex hormone. In view of appearance, each one about testis, it is ovate to take the form of the slightly flat one, lie in the scrotum. In foetus early period, they are in the abdominal cavity, before being born in, just drop to the scrotum. Adult's testis, about 4 centimetres long, about 3 centimetres wide, weight is about 20 grams. It expresses its size (15-20 ml) that the daily testis volume comes on clinic . The testis coming into being is comparatively relatively big, shrink to some extent in about 1-2 months after growing. Before the sexal maturity, the testis is basically in resting state, development is fast after entering adolescence. By about 50 years old, it shrinks back and diminishes gradually.
The color that the testis looks like fresh shelled shrimp, white touched with red, can also see the blood vessel of one of a silk above. Outer surface of testis cover into one slightly thick and the intersection of toughness and better pale membrane, play an important protection role in the testis essence. Cut white membrane, testis organization collapse from physical exhaustion, succeed one, can't maintain original shape of it. White membrane the intersection of sheath and membrane of testis, it whether the intersection of embryo and the intersection of period and testis bring peritoneum composition that get off drop. There is a small amount of liquid between white membrane and sheath membrane, keep lubricating, make the testis have certain activity. White membrane is extended inwards, it is mediastinal to form the radiatiform, divide each testis into about 200-300 intervals again from inside, we call them " The small leaf of testis " ,Wheel crooked very small pipeline in the every small leaf, name " song detailed to in charge of while being precise " . In adult, pipe diameter of it 150-250, different in size, more than among 30-70 centimetres, can up to 150 while being long most. Nearly have 300-1000 such a small tubes in each testis, if all join them, will probably 200-300 meters long. All thin precise tube in terminal and each other identical to gather first, make up the testis network. The divided into about ten and exports and manages small directlying of the network, cross the white membrane outside of testis in unison, converge into the epididymis finally. The sperm produces in the thin precise tube of song continually, the structure is so slight, complicated in the small testis, it is very large to make the testis produce the area which grows precise function, this is the reason why the testis can produce so many sperms every day.
Song have two kinds of cells in the thin precise upper skin of tube: One kind is at growing the meticulous afterbirth of different development stages, another kind supports cells. Grow the meticulous afterbirth to inlay in supporting the small irregular nest on the surface of cell, it is most inmature growing the meticulous afterbirth that is close to basilar membrane, and it is the ripe meticulous afterbirth to leave the central authorities and is in charge of one of a near ones. To develop with grow meticulous afterbirth, from basis to in charge of moving constantly they, a precise original cell is has silk splitting and miosis (meiosis) two times many times ,Can form 256 sperm cells that only have half the number chromosome, 50% among them include X chromosome, another 50% includes Y chromosome. Precise original cell and precise master cell appearance are round, without tail, the tail appears gradually until sperm's cell. Sperm's cells pass a series of change, ripe in the end, is formed like tadpole's sperm of kind, discharge into it in the thin precise tube of song. Support the function of cells to be numerous, can secrete many kinds of active substance, case regulate and help, grow meticulous afterbirth, split up, be ripe, discharge, engulf degradate, grow function such as the meticulous afterbirth by sperm. In adult's testis, are all producing sperms all the time, someone estimates, each gram testis tissue of adult can produce 300-600 sperms within every second, dual side testises can produce more than one hundred million sperms every day. One of this reasons that is a contraceptive device of the man controlling sperms to produce is more difficultly than to inhibits women's ovulating too.
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