4.2 Getting the spermatozoa ready

• Spermatozoa maturation steps
• Processes in the male genital tract
  • Processes in the testis
  • Processes in the epididymis
• The ejaculation and the ejaculate
  • The glands involved in the ejaculation
  • The seminal plasma
  • The spermatozoa

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 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.

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