Question | Answer |
external anal sphincter | attached anteriorly to central tendon, posteriorly to coccyx; loops around and attaches to anal canal |
external urethral sphincter | loops around urethra and vagina in female; loops around membranous urethra in male |
transverse perineus | central tendon, vagina, urethral sphincter |
diaphragm | central tendon |
levator ani | coccyx, levator ani of other side, and structures that penetrate it |
quadratus lumborum | transverse processes of lower lumbar vertebrae and rib 12 |
transverse abdominis | linea alba via rectus sheath |
internal oblique | linea alba via rectus sheath, lower 3 ribs |
external oblique | linea alba via rectus sheath, iliac crest |
rectus abdominis | sternum, costal cartilage of ribs 5-7 |
transversus thoracis | internal surface of costal cartilages of ribs 2-6 |
internal intercostal muscles | 11 pairs of muscles filling the space between ribs, with fibers running in the same direction as the internal obliques |
external intercostal muscles | 11 pairs of muscles filling the space between ribs, with fibers running in the same direction as the external obliques |
multifidus | spinous processes of the vertebrae 2-3 segments superior to the orgin |
semispinalis | spinous processes of the vertebrae 6-7 segments superior to the orgin, and posterior skull, near midline |
spinalis | spinous processes of cervical and thoracic vertebrae |
longissimus | transverse processes of the cervical and thoracic vertebrae, and the mastoid process of skull |
iliocostalis | transvere processes of C4-C6 and the angles of the ribs |
splenius | transverse process of C1-C4, mastoid process, and posterior skull |