Abdominal Wall Muscles Flashcards
External Oblique
Origin: outer surfaces of lower 8 ribs
Insertion: most insert into linea alba via a broad aponeurosis; some into pubic crest, tubercle and iliac crest
Action: Compress abdominal wall
Internal Oblique
Deep to external oblique
Origin: Lumbar fascia, iliac crest, inguinal ligament
Insertion: linea alba, pubic crest, last 3 or 4 ribs
Action: Compress abdominal wall
Transversus Abdominis
Deepest muscle of abdominal wall
Origin: inguinal ligament, lumbar fascia, last 6 ribs, iliac crest
Insertion: Linea alba, pubic crest
Action: Compresses abdominal contents
Rectus Abdominis
Same depth as internal obliques
Origin: Pubic crest and symphysis
Insertion: xiphoid process and costal cartilage of ribs 5-7
Action: Flex and rotate lumbar region of vertebral column, used in sit-ups
Quadratus Lumborum
Posterior abdominal wall
Origin: Iliac crest and lumbar fascia
Insertion: Transverse processes of upper lumbar vertebrae and lower margin of 12th rib
Action: Flexes vertebral column laterally -maintains upright posture
What 2 muscles does the Urogenital Diaphragm consist of?
1) Deep transverse perineal muscle
2) External Urethral Sphincter
Deep Transverse Perineal Muscle
Location: inbetween inferior pubic ramus
Action: Supports pelvic organs
External Urerthral Sphincter
Location: encircling urethra
Action: Constricts urethra
What 2 muscles does the Pelvic Diaphragm consist of?
1) Levator Ani
2) Coccygeus
Levator Ani
Location: forms a muscular “sling” around prostate (or vagina), urethra and anorectal junction
Action: Supports and maintains position of pelvic organs; you feel it when you cough, lifts anal canal when you poop
Coccygeus
Location: posterior to levator ani
Action: Supports pelvic organs, pulls coccyx forward after pooping and childbirth
Ischiocavernosus
Location: Pelvis to base of penis or clitoris
Action: Retards drainage and maintains erection
Bulbospongiosus
Location: Around base of penis and deep to labia
Actions: Empties male urethra, assists in errection
