Some body parts:
qaš head
c'æp shoulder
ŋær knee
pot' toe

These are zero-declension nouns.

            SG    PL
NOM  qaš  qaš-u
GEN    qaš-k' qaš-uk'
DAT    qaš-bi  qaš-ob
INST  qaš-wa qaš-ma

            SG    PL
NOM  c'æp  c'æp-u
GEN    c'æp-k'a c'æp-uk'
DAT    c'æp-pi  c'æp-ob
INST  c'æp-wa c'æp-ma

Note the labial stop assimilates to the stem's labial. Coda non-ejective stops are unreleased when they have the same point of articulation as the initial consonant of the following syllable: c'æp-ma [tʃʼæp̚.ma]. This could also be an opportunity for conditioning an environment for [ʋ] as an allophone of /w/? c'æpwa could be either [tʃʼæp̚.wa] or [[tʃʼæp.ʋa]. I like both.
A vowel is provided with the -k’ because of the preceding stop.

The reflexive pronoun is derived from the word for 'shoulder' c'æp combined with object markers (functioning as possessive suffixes): c'æpap ‘my shoulder’/’myself’. Formerly, the reflexive pronoun was derived from 'head' qaš combined with possessive affixes: qašap ‘my head’/’myself’. This has since been grammaticalized as an auxiliary verb for mediopassives.

Yukn-a sæp-e.
priestess-NOM bathe-3sfOBJ
A priestess bathes her.

Yukn-a qaš-e sæp.
priestess-NOM head-3sfOBJ bathe
A priestess bathes.

Yukn-a c’æp-e sæp-id.
priestess-NOM shoulder-3sfOBJ bathe-3sOBJ
A priestess bathes herself/washes her shoulder.

Yukn-a qaš-e sæp-id.
priestess-NOM head-3sfOBJ bathe-3sOBJ
A priestess washes her head.

P’at-a t’iɛ box-id.
stone-NOM ice break-3sOBJ
A stone breaks ice.

P’at-a qaš-id box.
Stone-NOM head-3sOBJ break
A stone breaks.

C’æp-e qaš-id box.
shoulder-3sfOBJ head-3sOBJ break
lit. Her shoulder is broken.



There. I contributed to lexicon, phonology, and morphosyntax all in one post