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The spermatozoa

Looking at a spermatozoon one distinguishes:

  • Head
  • Neck
  • Mid-piece
  • Principal piece
  • Endpiece

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 acrosome, in terms of volume, takes up around 40% of the head

Fig. 24 - The mature spermatozoon
media/module4/d2e_spermium.gif

1
Acrosome
2
Nucleus
3
Proximal centriole
A
Head
B
Neck
C
Mid piece
D
Principal piece
E
Endpiece

Legend
Fig. 24

The mature spermatozoon is slender; in the mid piece the mitochondria are arranged tightly and helically on the outer circular fibers. The DNA in the nucleus is maximally condensed.

More info

More information about the structures of a spermatozoon

In a normal ejaculate numerous malformed sperm cells are also present.
One encounters spermatozoa with the following abnormalities:

  • Deviant head forms
    • Too small
    • Too narrow
    • Piriform = pear-like head form
    • Two or three heads
  • Defects of the acrosomal cap
  • Two tails
Mroe info
More information about minimal amounts of sperm cells de spermatozoïdes.