Atlas of Anatomy

11 Abdominal Wall

Muscles of the Abdominal Wall

image The oblique muscles of the abdominal wall consist of the external and internal obliques and the transversus abdominis. The posterior or deep abdominal wall muscles (notably the psoas major) are functionally hip muscles (see p. 138).

Fig. 11.1   Muscles of the abdominal wall
Right side, anterior view.

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Inguinal Region & Canal

image The inguinal region is the junction of the anterior abdominal wall and the anterior thigh. The inguinal canal is an important site for the passage of structures into and out of the abdominal cavity (e.g., components of the spermatic cord).

Fig. 11.2   Inguinal region
Right side, anterior view.

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Fig. 11.3   Dissection of the inguinal region
Right side, anterior view.

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Fig. 11.4   Opening of the inguinal canal
Right side, anterior view.

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Abdominal Wall & Inguinal Hernias

image The rectus sheath is created by fusion of the aponeuroses of the transversus abdominis and abdominal oblique muscles. The inferior edge of the posterior rectus sheath is called the arcuate line.

Fig. 11.5   Abdominal wall and rectus sheath

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Fig. 11.6   Abdominal wall: Internal surface anatomy
Coronal section, posterior view. The three fossae of the anterior abdominal wall (circled) are sites of potential herniation.

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Inguinal and femoral hernias

Indirect inguinal hernias occur in younger males and may be congenital or acquired; direct inguinal hernias are always acquired. Femoral hernias are acquired and more common in females.

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Perineal Region

Fig. 11.7   Perineum and pelvic floor: Female
Lithotomy position, caudal (inferior) view. See p. 192 for the external genitalia.

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image The bilateral boundaries of the perineum in both sexes are the pubic symphysis, ischiopubic ramus, ischial tuberosity, sacrotuberous ligament, and the coccyx. The green arrows indicate the anterior recess of the ischioanal fossa, superior to the urogenital muscles.

Fig. 11.8   Perineum and pelvic floor: Male
Lithotomy position, caudal (inferior) view. See p. 196 for the genitalia.

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Adominal Wall Muscle Facts

Fig. 11.9   Anterior muscles
Anterior view.

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Fig. 11.10   Anterolateral muscles
Anterior view.

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Fig. 11.11   Posterior muscles
Anterior view. The psoas major and iliacus are together known as the iliopsoas.

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Fig. 11.12   Anterior and posterior abdominal wall muscles
Anterior view.

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Pelvic Floor Muscle Facts

Fig. 11.13   Muscles of the pelvic floor
Superior view.

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Fig. 11.14   Sphincter and erector muscles of the pelvic floor
Inferior view. See pp. 194203.

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Fig. 11.15   Pelvic floor
Female pelvis.

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