Links for the previous four parts:
The mouth muscles can be tricky so I've broken them down into three sections (above the mouth, at the mouth and below the mouth). Here's what's above the mouth:
Quadratus labii superioris
L. quadratus—square-shaped [muscle] + labii—of lip
angular head (levator labii superioris alaeque nasi)
origin: inner margin of orbit
insertion: nasolabial furrow and ala (wing of the nose)
action: raises the ala and upper lip
infraorbital head (levator labii superioris)
origin: lower margin of orbit
insertion: nasolabial furrow
action: raises the ala and upper lip
zygomatic head (zygomaticus inferioris)
origin: zygomatic bone behind the suture
insertion: nasolabial furrow
action: raises the ala and upper lip
And all together now!
Next: the muscles around the mouth.