C. Muscles of the Pelvic Region 1. Internal oblique- compresses abdomen, flattens lumbar curve of the spine a. Originates from the pelvis b. Inserts at ribs, pubic bone, and linea alba

2. Muscles of the pelvic floor a. Levator ani- split into two muscles 1. Pubococcygeus- supports and raises pelvic floor constricts and draws anus toward pelvis a. Originates from pelvis b. Inserts at coccyx, urethra, anal canal, and perineum

2. Iliococcygeus- same function as pubococcygeus a. Originates from ischial spine b. Inserts at coccyx

b. Coccygeus- same as the levator. ani plus pulls coccyx forward after b. Coccygeus- same as the levator ani plus pulls coccyx forward after defecation and childbirth 1. Originates from the ischial spine b. Inserts at lower sacrum and upper coccyx

3. The perineum- outlet of the pelvis, 3. The perineum- outlet of the pelvis, diamond shaped area at the lower end of the trunk between the thighs and buttocks a. Cut during an episiotomy b. Superficial transverse perineus- stabilizes central tendon of the perineum 1. Originates from the ischial tuberosity 2. Inserts at the central tendon of perineum

c. External anal sphincter- keep anal canal and orifice closed 1. Originates from anacoccygeal raphe 2. Inserts at central tendon of perineum