Semantics

back of the head
Ї смотрљл на егћ крџглый затІлок и старђлся не отставђть. I watched the round back of his head and tried to keep up.
back of the neck
Ћн потёр свћй крђсный от смущљния затІлок, нћ ничегћ не сказђл. He rubbed the back of his neck, which had turned red from embarrassment, but he said nothing.
nape
Вћлосы у неё бІли сћбраны на затІлке в тугћй џзел, а на вискђх зђвиты в мљлкие кудрїшки. Her hair was gathered into a tight knot at the nape of her neck, and curled in small ringlets on her temples.
This entry is concerned with the word затІлок, denoting the back of the head and neck in humans. The corresponding term for animals is загрќвок.