1. Abdominal Wall

2. Landmarks: bony & soft costal arch: formed by #7-10 costal cartilages
a. infrasternal angle - sharp upward angle at midline, xiphoid process at the apex
b. epigastric fossa - depression just inferior to xiphoid

4. Coxal bones Three bones fused together
ilium: anterior superior iliac spine; iliac crest
ischium
pubis: pubic symphysis,
inguinal ligament (below): indicated at surface by depression separating leg from abdomen

9. Abdominal wall
Linea alba: midline from xiphoid to pubic bone, umbilicus - at level of L4
Linea semilunaris: parallels linea alba on each side; marks lateral border of rectus abdominis
Tendinous intersections: 3 horizontal divisions of rectus abdominis between linea semilunaris

11. Regions

12. Superficial vessels
thoracoepigastric veins: drain laterally from umbilical level up
anterior perforating veins: closer to midline
umbilical venous plexus (caput medusae may seen in portal hypertension)
superficial epigastric artery, vein
superficial circumflex iliac artery vein

15. Nerves
Thoracoabdominal nerve: continuations of intercostals 7-11 & subcostal from thorax to abdomen, between internal oblique & transverse abdominis
Anterior, lateral cutaneous nerve: terminal branches of thoracoabdominal nerve to the surface
T7-9 to skin superior to umbilicus
T10 to skin surrounding umbilicus
T11-12, L1 to skin inferior to umbilicus
Iliohypogastric nerve: to skin over inguinal region
Ilioinguinal nerve: just inferior to iliohypogastric to skin of superior, medial thigh

18. Muscles External oblique muscle Internal oblique muscle
Transversus abdominis
Rectus abdominis

19. EXTERNAL ABDOMINAL OBLIQUE
Origin
Anterior fibers: external surfaces of ribs five through eight interdigitating with serratus anterior
lateral fibers: external surface of ninth rib, interdigitating with serratus anterior; and external surfaces of 10th, 11 th ans 12th ribs, interdigitating with latissnus dorsi
Insertion
Anterior fibers: into a board, flat aponeurosis, terminating in the linea alba, which is a tendinous rephe which extends from the xiphoid
Lateral fibers: as the inguinal ligament, into anterior superior spine and public tubercle, and into the external lip of anterior one half of iliac crest.

20. EXTERNAL ABDOMINAL OBLIQUE
Action
Anterior fibers: acting bilaterally, the anterior fibers flex the vertebral column approximating the thorax and pelvis anteriorly, support and compress the abdominal viscera, depress the thorax, and assist in respiration. Acting unilaterally with the anterior fibers of the Internal Oblique on the opposite site, the anterior fibers of External Oblique rotate the vertebral column, bring the thorax forward (when the pelvis is fixed), or the pelvis backward (when the thorax is fixed). For example, with the pelvis fixed, the right external oblique rotates the thorax counterclockwise, and the left external oblique rotates the thorax clockwise.

21. EXTERNAL ABDOMINAL OBLIQUE
Action
Lateral fibers: acting bilaterally, the lateral fibers of the external oblique flex the vertebral column, with major influence on the lumbar spine, titling the pelvis posteriorly. Acting unilaterally with the lateral fibers of the internal oblique on the same side, these fibers of the external oblique laterally flex the vertebral column, approximating the thorax and iliac crest. These external oblique fibers also act with the internal oblique on the opposite side to rotate the vertebral column. The external oblique, in its action on the thorax, is comparable to the sternocleidomastoid in its action on the head.

22. EXTERNAL ABDOMINAL OBLIQUE
Nerve
Anterior fibers: T5, 6, T7-T12
Lateral fibers: T5, 6, T7-T12
Direction of the fibers:
Anterior fibers: the fibers extend obliquely downward and medialward with the uppermost fibers from the xiphoid
Lateral fibers: fibers extend obliquely downward and medialward, more downward than the anterior fibers

23. INTERNAL ABDOMINAL OBLIQUE
Origin
Lower anterior fibers: middle one third of intermediate line of iliac crest, and thoracolumbar fascia
Upper anterior fibers: anterior one third of intermediate line of iliac crest
Lateral fibers: middle one third of intermediate line of iliac crest, and thoracolumbar fascia
Insertion
Lower anterior fibers: inferior borders of 10th, 11th, and 12th ribs and linea alba by means of aponeurosis
Upper anterior fibers: linea alba by means of aponeurosis
Lateral fibers: inferior borders of 10th, 11th, and 12th ribs and linea alba by means of aponeurosis

24. INTERNAL ABDOMINAL OBLIQUE
Action
Lower anterior fibers: acting bilaterally, the lateral fibers flex the veterbral column, approximating the thorax and pelvis anteriorly, and depress the thorax. Acting unilaterally with the lateral fibers of the external oblique on the same side, these fibers of the internal oblique laterally flex the vertebral column, approximating the thorax and pelvis. These fibers also act with the external oblique on the opposite side to rotate the vertebral column.

25. INTERNAL ABDOMINAL OBLIQUE
Action
Upper anterior fibers: acting bilaterally, the upper anterior fibers flex the vertebral column, approximating the thorax and pelvis anteriorly, support and compress the abdominal viscera, depress the thorax, and assist in respiration. Acting unilaterally, in conjuction with the anterior fibers of the external oblique on te oppisite side, the ipper anterior fibers of the internal oblique rotate the vertebral column, bringing the thorax backward (when the pelvis is fixed), or the pelvis forward (when the thorax is fixed). For example, the right internal oblique rotates the thorax clockwise and the left internal oblique rotates the thorax couinterclockwise on a fixed pelvis.

26. INTERNAL ABDOMINAL OBLIQUE
Action
Lateral fibers: acting bilaterally, the lateral fibers flex the veterbral column, approximating the thorax and pelvis anteriorly, and depress the thorax. Acting unilaterally with the lateral fibers of the external oblique on the same side, these fibers of the internal oblique laterally flex the vertebral column, approximating the thorax and pelvis. These fibers also act with the external oblique on the opposite side to rotate the vertebral column.

27. INTERNAL ABDOMINAL OBLIQUE
Nerve
Lower anterior fibers: T7-11, T12, iliohypogastric and ilioinguinal, ventral rami
Upper anterior fibers: T7-11, T12, iliohypogastric and ilioinguinal, ventral
Lateral fibers: T7-11, T12, iliohypogastric and ilioinguinal, ventral rami
Direction of fibers:
Lower anterior fibers: fibers extend obliquely upward and medialward, more upward than the anterior fibers
Upper anterior fibers: fibers extend obliquely medialward and upward
Lateral fibers: fibers extend obliquely upward and medialward, more upward than the anterior fibers

28. TRANSVERSUS ABDOMINIS
Origin
inner surfaces of cartilages of lower six ribs, interdigitating with the diaphragm; thoracolumbar fascia; anterior three fourths of internal lip of iliac crest; and lateral one third of inguinal ligament
Action
Acts likes a girdle to flatten the abdominal wall and compress the abdominal viscera; upper portion helps to decrease the infrasternal angle of the ribs as in expiration. This muscle has no action in lateral trunk flexion except that it acts to compress the viscera and stabilize the linea alba, thereby permiting better action by anteriolateral trunk muscles
Insertion
linea alba by means of a board aponeurosis, pubic crest and pectin publis
Nerve
T7-T12, iliohypogastric, ilioinguinal, ventral divisions Direction of fibers: transverse (horizontal)

29. RECTUS ABDOMINIS Origin Action Insertion Nerve
pubic crest and symphysis
Action
flexes the vertebral column by approximating the thorax and pelvis anteriorly. With the pelvis fixed, the thorax will move toward the pelvis; with the thorax fixed, the pelvis will move toward the thorax.
Insertion
costal cartilages of fifth, sixth, and seventh ribs, and xiphiod process of sternum
Nerve
T5-T12, ventral rami

35. Inguinal triangle bounded by
lateral border of rectus abdominis muscle medially
inguinal ligament inferiorly
inferior epigastric artery laterally

37. Inguinal canal roof: posterior wall: Floor: Anterior wall:
internal oblique & transversus abdominis muscle
posterior wall:
transveralis fascia, reinforced medially by conjoint tendon (internal oblique & transversus abdomilis muscle)
Floor:
Superior surface of inguinal ligament
Anterior wall:
aponeurosis of the external oblique muscle
Superficial & deep ring

51. Graham “Mr Europe" Black had his hernia repaired at the Centre on Friday and on Monday he was ‘working-out' at the gym!  (not always recommended for the rest of us!)