acrosomal cap

(redirected from acrosomal head cap)


A caplike organelle or saccule derived from Golgi elements that surround the anterior two thirds of the nucleus of a sperm. Enzymes contained within this structure probably facilitate the sperm's penetration of the zona pellucida of the oocyte.
Synonym(s): acrosomal cap, head cap
[acro- + G. soma, body]

acrosomal cap, acrosomal head cap

See acrosome.

ac·ro·so·mal cap

(ak'rō-sō'măl kap)
A collapsed caplike membranous vesicle that covers the anterior part of the nucleus of a spermatid, derived from the acrosomal granule.