armpit, arms
胳 centers on the area where the arm meets the body: the armpit, and by extension the arms themselves.
胳 combines the flesh radical ⺼ with 各, which likely contributes the sound. The character originally referred to the armpit or the upper arm area.
The flesh radical ⺼ on the left suggests a body part, and 各 on the right looks like a person with arms akimbo, highlighting the armpit area.
For カク, imagine a person raising their arm to reveal the armpit, and a friend says 'Cock-a-doodle-doo!' to make them laugh: 'cock' cues カク.