Flexor
The flex
A flexor muscle.
The flexor is a muscle that bends part of your body.
neck
The cornea and the lens both bend light as it enters the eye, helping to focus it onto the retina at the back of the eye.
Spine. Bone, not muscle.
Delta is a body part and also a name for a landform where a river flows into an ocean or a larger body of water.
The knee is a body part that has "ee" in its name.
The Bends
eyes
The cornea is the part of the human eye that bends light rays the most when focused on a distant object.