Thoracic and Abdominal Walls: Vessels and Nerves 215

Thoracic and abdominal walls with vessels and nerves (anterior aspect). Right side: superficial layers; left side: deeper layers. Pectoralis

major and minor muscles, the external and internal intercostal muscles on the left side have been removed to display the intercostal nerves.

The anterior layer of rectus sheath, the left rectus abdominis muscle, and the external and internal abdominal oblique muscles have been

removed to show the thoraco-abdominal nerves within the abdominal wall.

216 Thoracic and Abdominal Walls: Vessels and Nerves

Abdominal wall with vessels and nerves. The left rectus abdominis muscle has been

divided and reflected to display the inferior epigastric vessels. The left internal abdominal

oblique muscle has been removed to show the thoraco-abdominal nerves.

1 Rectus abdominis muscle

2 Tendinous intersection

3 Internal abdominal oblique muscle

4 External abdominal oblique muscle

(reflected)

5 Anterior superior iliac spine

6 Ilio-inguinal nerve

7 Spermatic cord

8 Costal margin

9 Superior epigastric artery

10 Thoraco-abdominal (intercostal)

nerves

11 Posterior layer of rectus sheath

12 Transversus abdominis muscle

13 Semilunar line

14 Arcuate line

15 Inferior epigastric artery

16 Inguinal ligament

1 Internal thoracic artery

2 Intercostal artery

3 Superior epigastric artery

4 Musculophrenic artery

5 Gallbladder

6 Rectus abdominis muscle

7 External abdominal oblique muscle

8 Deep circumflex iliac artery

9 Superficial epigastric artery

10 Inferior epigastric artery

11 Superficial circumflex iliac artery

12 Femoral artery

13 Intercostal nerve

14 Thoraco-abdominal nerve (T10)

15 Transversus abdominis muscle

16 Posterior layer of the rectus sheath

17 Iliohypogastric nerve (L1)

18 Ilio-inguinal nerve (L1)

19 Spermatic cord

20 Genitofemoral nerve (L1, L2)

a Femoral branch

b Genital branch

Arteries and nerves that supply the thoracic and abdominal walls.

Note their segmental arrangement (schematic drawing).

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Inguinal Region in the Male

1 Aponeurosis of external abdominal oblique muscle

2 Superficial circumflex iliac vein

3 Inguinal ligament

4 Lateral crus of inguinal ring

5 Superficial epigastric vein

6 Saphenous opening

7 Femoral artery and vein

8 Great saphenous vein

9 Anterior cutaneous branches of femoral nerve

10 Anterior layer of rectus sheath

11 Intercrural fibers

12 Superficial inguinal ring

13 Spermatic cord and genital branch

of genitofemoral nerve

14 Penis with dorsal nerves and deep dorsal vein

of penis

15 Aponeurosis of external abdominal oblique

muscle (divided and reflected)

16 Internal abdominal oblique muscle

17 Ilio-inguinal nerve

18 Anterior cutaneous branches of iliohypogastric

nerve

19 Superficial external pudendal veins

Inguinal canal in the male, right side (superficial layer, anterior aspect).

There is a small inguinal hernia (arrow).

Inguinal canal in the male, right side (anterior aspect). The external

abdominal oblique muscle has been divided to display the inguinal canal.

Regions and reference lines

for delineating surface projections.

1 Median line

2 Lateral sternal line

3 Parasternal line

4 Midclavicular line

5 Axillary line

6 Transpyloric plane

7 Transtubercular plane

8 Hypochondriac region

9 Epigastric region

10 Lumbar region

11 Umbilical region

12 Iliac region

13 Hypogastric region

218 Inguinal Region in the Male

1 Internal abdominal oblique muscle (reflected)

2 Transversus abdominis muscle

3 Inguinal ligament

4 Spermatic cord with the exception of the ductus

deferens (divided and reflected)

5 Ductus deferens and interfoveolar ligament

6 Superficial circumflex iliac artery

7 Femoral artery and vein

8 Superficial inguinal lymph nodes and inguinal

lymph vessel

9 Inferior epigastric artery and vein

10 Falx inguinalis or conjoint tendon (cut)

11 Pubic branch of inferior epigastric artery

12 Superficial inguinal ring

13 Penis

14 External abdominal oblique muscle

15 Anterior superior iliac spine

16 Intercrural fibers

17 Fascia lata and sartorius muscle

18 Saphenous opening and great saphenous vein

19 Deep inguinal ring

20 Skin of scrotum and dartos muscle

21 Cremaster muscle

22 Internal spermatic fascia

23 Ductus deferens

24 Epididymis

25 Peritoneum (blue)

26 Remnant of processus vaginalis

27 Tunica vaginalis testis

28 Rectus abdominis muscle

29 Spermatic cord with ductus deferens covered

by external spermatic fascia

30 Anterior layer of rectus sheath

31 Suspensory ligament of penis

32 Testis and epididymis

33 Ductus deferens

34 Pampiniform venous plexus and testicular

artery

35 Inferior epigastric artery

36 Lateral femoral cutaneous nerve

37 Ilio-inguinal nerve

38 Femoral nerve

39 Sartorius muscle

40 Deep dorsal vein of penis

Inguinal canal in the male, right side (deep layer, anterior aspect).

Spermatic cord with exception of ductus deferens (probe) has been divided

and reflected.

General characteristics of lower part of anterior

abdominal wall and inguinal canal (schematic drawing).

Inguinal hernias may either pass through

the inguinal canal lateral to the inferior

epigastric artery (indirect or lateral inguinal

hernias, A and C) or directly penetrate the

abdominal wall through the inguinal triangle

located medial to the inferior epigastric

artery (direct or medial inguinal hernias, B).

The lateral hernias can be congenital if the

vaginal process remains open (C) or acquired

(A) if the hernia develops independently of a

patent processus vaginalis.

Femoral hernias generally protrude

through the femoral ring below the inguinal

ligament. Proper assessment of the site of

herniation requires the identification of

both the inguinal ligament and the epigastric

artery.

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