Spermatogenesis – Embryology

Nuclear condensation The nucleus becomes smaller, denser and takes on a characteristic, flattened form. Seen from above, the nucleus is oval and, from the narrow side, is pear-shaped. The acrosome lies over the tip. Nucleus and acrosome form the sperm cell's head that is bound to the mid-piece by a short neck.

Acrosome formation The Golgi complex engender the vesicles, which then merge into a larger formation that settles close to the cell nucleus and finally inverts itself like a cap over the largest part of the nucleus. The acrosome corresponds functionally to a lysosome and thus contains lysosomal enzymes (hyaluronidase among others).

Development of the flagellum The future axonemal structure grows out of one centriole (distal). This consists of a bundle of nine peripheral double microtubules and two single ones in the center. During its development, through the rotation of the nucleus and acrosomal vesicle, the flagellum primordium comes to lie on the opposite side of the acrosome.

Four parts of the finished flagellum can be distinguished:

The mature sperm cell is approximately 60 mm long and completely enveloped by the plasma membrane.

Read the original post:
Spermatogenesis - Embryology