any of the muscles that raise a body part. In humans these include the levator anguli oris, which raises the corner of the mouth; the levator ani, collective name for a thin sheet of muscle that stretches across the pelvic cavity and helps hold the pelvic viscera in position, forming a kind of sphincter around the vagina in the female and the anal canal in both sexes; the levatores costarum, which help raise the ribs during respiration; the levator labii superioris and levator labii superioris alaeque nasi, which raise the upper lip; the levator palpebrae superioris, which raises the upper eyelid; the levator prostatae, a part of the levator ani in the male that supports the prostate gland and is involved in control of urination; the levator scapulae, a straplike muscle of the shoulder that helps raise and rotate the shoulder blade; and the levator veli palatini, which raises the soft palate of the mouth.