middle piece


piece

 [pēs] a part or portion.end piece the terminal portion of the tail of the spermatozoon. See illustration at spermatozoon.middle piece an anterior portion of the tail of the spermatozoon, between the neck and the anulus. See illustration at spermatozoon.principal piece the main portion of the tail of a spermatozoon, beginning at the anulus and gradually tapering toward the piece" >end piece. See illustration at spermatozoon.

mid·dle piece

a part of the spermatozoon characterized by an axoneme and by a sheath of mitochondria arranged in a tight helix.