Muscles of the Anterior Abdominal Wall

• Muscle
• Origin
• Insertion
• NerveAction

External oblique
External surface of lower eight ribs
Anterior half of iliac crest; anterior-superior iliac spine; pubic tubercle; linea alba
Intercostal; subcostal n.
Compresses abdomen; flexes trunk; active in forced expiration

Internal oblique
Lateral two thirds of inguinal ligament; iliac crest; thoracolumbar fascia
Lower four costal cartilages; linea alba; pubic crest; pectineal line
Intercostal n.; subcostal; iliohypogastric and ilioinguinal nn.
Compresses abdomen; flexes trunk; active in forced expiration

Transverse
Lateral one third of inguinal ligament; iliac crest; thoracolumbar fascia; lower six costal cartilages
Linea alba; pubic crest; pectineal line
Intercostal ; subcostal iliohypogastric and ilioinguinal nn.
Compresses abdomen; depresses ribs

Rectus abdominis
Pubic crest and pubic symphysis
Xiphoid process and costal cartilages
Intercostal ; subcostal n.
Depresses ribs; flexes trunk

Pyramidal
Pubic body
Linea alba
Subcostal

Tenses linea alba
Cremaster
Middle of inguinal ligament; lower margin of internal oblique muscle
Pubic tubercle and crest

Genitofemoral
Retracts testis