Sperm (cell): male gamete composed of a head and a flagellum.
Acrosome: organelle situated a the point of the head of a spermatozoid.
Neck: part of a spermatozoid between the head and the body.
Tail: end of a spermatozoid.
Middle piece: main part of a spermatozoid.
Head: important end of a spermatozoid.

Photo :

EN : Tongue lower surface
FR : Langue face inférieure
ES : Lengua cara inferior

          lower surface

Since the tongue contains no bony supports for the muscles, the tongue is an example of a muscular hydrostat, similar in concept to an octopus arm. Instead of bony attachments, the extrinsic muscles of the tongue anchor the tongue firmly to surrounding bones and prevent the mythical possibility of 'swallowing' the tongue.

Animation : Fertilization

Thanks to YouTube for allowing us to watch this video.