Abdomen

The Abdomen Surface Anatomy, Muscles and Peritoneum

www.smso.net

Abdominopelvic Cavity Largest part of ventral body cavity Abdominal Stomach, liver, kidneys, etc

Pelvic Bladder, some reproductive organs, rectum

Two cavities are continuous pg 12

www.smso.net

Abdomen Umbilicus = navel

pg 742

Linea alba = white line Xiphoid process to pubic symphysis Tendinous line

Inferior Boundaries Iliac crest Ant. Sup. Iliac spine Inguinal ligament Pubic crest www.smso.net

Pg 187

Four Abdominal Quadrants

www.smso.net

Pg 16

Muscles of Abdominal Wall

pg 278

www.smso.net

No bony reinforcement 3 sheet-like layers Continuous with layers of intercostal muscles Fibers of layers run in different directions for strength Ends in aponeurosis which contains rectus abdominis muscle Function: hold in organs, move trunk,

Wall External Obliques O: lower 8 ribs I: aponeurosis to linea alba Function: Flex trunk, compress abd. wall (together) Rotate trunk (separate sides)

Internal Obliques O: Lumbar fascia, iliac crest, inguinal ligament I: Linea alba, pubic crest, last 3-4 ribs, costal margin Function: Same as External obliques

Transversus Abdominis O:same as Internals, plus last 6 ribs I: Xiphoid process, costal cart. 5-7 Function: Compress abdomen

Rectus Abdominis O: Pubic crest, pubic symphysis cart 5-7 www.smso.net

I: Xiphoid, cost

Muscles of the Anterior Abdomen Wall

All muscles of anterior abdomenwww.smso.net innervated by INTERCOSTAL nerves

Muscles of the Posterior Abdominal Wall Iliopsoas Psoas major O: Lumbar vertebrae + T12 I: Lesser trochanter of femur via iliopsoas tendon Function: Thigh flexion, trunk flexion, lateral flexion

Iliacus O: Iliac fossa, ala of sacrum I: Lesser trochanter of femur via iliopsoas tendon Function: Thigh flexion, trunk flexion

Quadratus lumborum O: iliac crest, lumbar fascia I: trans. proc of upper lumbar vertebrae Function: Flex vertebral column www.smso.net

Quadratus lumborum

Muscles of Posterior Abdominal Wall

Iliiopsoas Iliacus Psoas major

Pg 299 www.smso.net

Peritoneum Extension of serous membrane in the abdomino-pelvic cavity Mesentery: Double layer of peritoneum Hold organs in place Store fat Route for vessels + nerves

Retroperitoneal: some organs behind peritoneum (eg) duodenum, ascending + descending colon, rectum, pancreas Peritoneal: remain surrounded by peritoneal cavity (eg) liver, stomach, www.smso.net

Peritoneal vs Retroperitoneal

Pg 13, 614 www.smso.net