Radicals: がしら (gashira) endings?

Question

Does somebody know for what the [がしら]{gashira} ending stands in radicals like:

• eight (はちがしら{hachigashira})
• winter (ふゆがしら{fuyugashira}), or
• short thread (いとがしら{itogashira})?

Is it part of あし{ashi} (bottom radical position) or ashi variant (center radical position / top and bottom radical position)? I understand the other endings (kanmuri, gamae-kamae, hen-ben, nyō, tare, etc.).

I know some of them don't have those endings and could be phonetic (sound) parts of kanji and not semantic (meaning).

Answer 1

[かしら]{頭} (the 漢字 is also read あたま) means "head" and ふゆがしら etc. refer to the top part of the component.