External Oblique Muscle Origin Fleshy digitations from the lower 8 ribs
External Oblique Muscle The muscle is inserted by fleshy fibers as well as aponeurosis, as follows: A- Fleshy fibers: Outer lip of the iliac crest B- Aponeurosis: 1.Medial part → linea alba from xiphoid process to symphysis pubis 2.Lateral part → folded upwards & backwards upon itself to form the inguinal ligament (ASIS → pubic tubercle) Insertion Xiphoid Process Symphysis Pubis
External Oblique Muscle Direction of fibers Downward Forwards Medially
External Oblique Muscle Nerve Supply I II Intercostal nerves (T7 -T11) & Subcostal nerve (T12)
Internal Oblique Muscle Origin Insertion 1.Anterior 2/3 of the intermediate line of the iliac crest 2.The lateral 2/3 of the inguinal ligament 3.Lumbar fascia 1.Lower 6 costal cartilages 2.Xiphoid process 3.Linea Alba 4.Pubic crest
Internal Oblique Muscle Direction of fibers Upwards Forwards Medially Nerve Supply T7-T12 Iliohypogastric n. Ilioinguinal n.
Transversus Abdominis Muscle Origin 1- Lower 6 intercostal cartilages 2- Lumbar Fascia 3- Ant. 2/3 of inner lip of iliac crest 4- Lat. 1/3 of inguinal ligament
Insertion 1- Xiphoid Process 2- Pubic Crest 3- Linea Alba
Direction of fibers Horizontally
Nerve Supply T7-T12 Iliohypogastric n. Ilioinguinal n.
Rectus Abdominis Muscle Origin From the pubic crest Insertion 7th, 6th, 5th costal cartilages Xiphoid process
Rectus Abdominis Muscle The muscle is divided into segments by tendinous intersections, Which indicate that the muscle arises from a number of myotomes, fused together 1- Segmental nerve supply. 2- Hematoma of rectus m. is localized 2- In paramedian incision displace m. laterally (n. supply comes from lateral) Surgical Importance
Pyramidalis Muscle It is a landmark of linea alba intraoperative
Actions of Anterior Abdominal Wall Muscles They assist in raising the intra-bdominal pressure (so, they help in vomiting, cough, delivery, etc….) Keep the abdominal viscera in position. Rectus abdominis flexes the trunk, while the 2 oblique muscles bend the trunk laterally. Act as accessory expiratory muscles. Lower midline & paramedian incisions.
Medially Laterally Rectus Sheath Linea Alba Linea Semilunaris Arcuate Line
Falciform Ligament External Oblique Internal Oblique Transversus Abdominis Ant. Layer of Rectus Sheath Post. Layer of Rectus Sheath Rectus Abdominis Above Arcuate Line SKIN Peritoneum Transverslais Fascia
External Oblique Internal Oblique Transversus Abdominis Ant. Layer of Rectus Sheath Rectus Abdominis Below Arcuate Line Urachus in Median Umbilical Fold Medial Umbilical Ligament Transverslais Fascia SKIN Peritoneum
Superior epigastric a. Subcostal a. Inferior epigastric a. Deep circumflex iliac a. - I - Internal Mammary a. - III - External Iliac a. - II - Descending Aorta 10th, 11th intercostal a.