The abdominal wall and inguinal region

1. The abdominal wall and inguinal region Dr. Nabil Khouri MD. Ph.D

2. Bony framework

3. The abdomen is the region of the body that is located between the diaphragm above and the pelvic inlet below.

4. Dermatomss Skin

5. Two transverse lines • The lower plain INTERTUBERCULAR plain extends between the Rt. And Lt. iliac tubercles • The upper subcostal plain extends between the lowest point of the costal edge. • Or TRANSPYLORIC plane that pass through L1 or the midway between the jugular notch and the pubic symphysis. • Abdominal regions. • The abdomen can be divided to 9 regions by four imaginary lines. • The Rt. And Lt. vertical lines extending from the midclavicular point superiorly to midinguinal point inferiorly.

6. And Deep fascia

7. Skin • Superficial fascia. • Superficial fatty layer (CAMPER’S FASCIA). It’s continuous with superficial fat over the rest of the body. In the scrotum is modified as a thin smooth muscular layer called DARTOS MUSCLE. • Deep membranous layer.(SCARPA’S FASCIA). Its thin and fades out superiorly andlaterally where it becomes continuous with the superficial fascia of the back and the thorax. Inferiorly passes on to the front of the thigh and fuses with the deep fascia of the thigh about 2.5 cm bellow the inguinal ligament. In the midline inferiorly. It form a tubular sheath for the penis (or clitoris) so it doesn’t attach to the pubis.

8. Bellow the perineum • Inters the wall of the scrotum. From here it passes to be attached on each side to the pubic arch and there its referred asCOLLESFASCIA. The Deep fascia. Is a thin layer of connective tissue covering the muscles, it lies immediately deep to the membranous layer of superficial fascia.

9. Muscles of the anterior abdominal wall. It connects the thoracic cage to the hip bones as a three large flat sheets and a wide vertical muscle. • External oblique. • Internal oblique. • Transversus abdominal. • Rectus abdominis.

11. External Oblique • The external oblique muscle is a broad, thin, muscular sheet that ARISES from the outer surfaces of the lower eight ribs and fans out to be INSERTED into • The xiphoid process. • The linea alba. • The pubic crest. • The pubic tubercle. • The anterior half of the iliac crest. • Forms the inguinal ligament by its folding

12. Internal Oblique • lies deep to the external oblique; most of its fibers run at right angles to those of the external oblique. It arises from • The lumbar fascia, • The anterior two thirds of the iliac crest, • The lateral two thirds of the inguinal ligament. • The muscle fibers radiate as they pass upward and forward. It inserts into • The lower borders of the lower three ribs and their costal cartilages. • The xiphoid process. • The linea alba. • The symphysis pubis.

13. The Transversus muscle • is a thin sheet of muscle that lies deep to the internal oblique, and its fibers run horizontally forward • It arises from the • Deep surface of the lower six costal cartilages and margins • The lumbar fascia (posterior aponeurosis) • The anterior two thirds of the iliac crest, • The lateral third of the inguinal ligament.

14. Rectus Abdominis • The rectus abdominis is a long strap muscle that extends along the whole length of the anterior abdominal wall. • It is broader above and lies close to the midline, being separated from its fellow by the linea alba. • It arises by two heads • from the front of the symphysis pubis. • from the pubic crest. • It inserts • into the fifth, sixth, and seventh costal cartilages and • the xiphoid process . • When it contracts, its lateral margin forms a curved ridge that can be palpated and often seen and is termed the LINEA SEMILUNARIS, this extends from the tip of the ninth costal cartilage to the pubic tubercle.

16. The rectus abdominis muscle is divided into distinct segments by three transverse tendinous intersections: at the level of the • xiphoid process. • umbilicus. • halfway between these two. These intersections are strongly attached to the anterior wall of the rectus sheath.

17. Pyramidalis • The pyramidalis muscle is often absent. • It arises by its base from the anterior surface of the pubis. • it inserts into the linea alba. It lies in front of the lower part of the rectus abdominis. NOT: The posterior border of the external oblique muscle is free, whereas the posterior borders of the internal oblique and transversus muscles are attached to the lumbar vertebrae by the lumbar fascia

18. Above the costal margin, the anterior wall is formed by the aponeurosis of the external oblique. The posterior wall is formed by the thoracic wall—that is, the fifth, sixth, and seventh costal cartilages and the intercostal spaces. • Between the costal margin and the level of the anterior superior iliac spine, the aponeurosis of the internal oblique splits to enclose the rectus muscle; the external oblique aponeurosis is directed in front of the muscle, and the transversus aponeurosis is directed behind the muscle. • Between the level of the anterosuperior iliac spine and the pubis, the aponeuroses of all three muscles form the anterior wall. The posterior wall is absent, and the rectus muscle lies in contact with the fascia transversalis.

19. At the site where the aponeuroses forming the posterior wall pass in front of the rectus at the level of the anterior superior iliac spine, the posterior wall has a free, curved lower border called the arcuate line • At this site, the inferior epigastric vessels enter the rectus sheath and pass upward to anastomose with the superior epigastric vessels.

21. The rectus abdominis is enclosed between the aponeuroses of the external oblique, internal oblique, and transversus muscles which form the rectus sheath

22. Rectus Sheath • The rectus sheath is a long fibrous sheath that encloses the rectus abdominis muscle and pyramidalis muscle (if present) • and contains • rectus abdominis muscle and pyramidalis muscle (if present) • the anterior rami of the lower six thoracic nerves and • the superior and inferior epigastric vessels • and lymph vessels.

23. Inguinal region

24. Between the anterior superior iliac spine and the pubic tubercle, the lower border of the external oblique muscle aponeurosis is folded backward on itself, forming the inguinal legament Inguinal ligament.

25. It extend from the ASIP to the symphesis pubis to from the medial end of the ligament, the lacunar ligament that extends backward and upward into the pectineal line on the superior ramus of the pubis • The inferior rounded border of the inguinal ligament is attached the deep fascia of the thigh, the FASCIA LATA • The lateral part of the posterior edge of the INGUINAL LIGAMENT gives origin to: • Part of the internal oblique • The transversusabdominis muscles. • Its sharp, free crescentic edge forms the medial margin of the FEMORAL RING

26. The internal oblique has a lower free border that arches over the spermatic cord (or round ligament of the uterus) and then descends behind it to be attached to the pubic crest and the pectineal line. • Near their insertion, the lowest tendinous fibers are joined by similar fibers from the transversus abdominis to form the conjoint tendon. • The conjoint tendon is attached medially to the linea alba.

27. Conjoint tendon

28. Superficial inguinal ring is a triangular-shaped defect in the external oblique aponeurosis lies immediately above and medial to the pubic tubercle. • Its margins are referred as crura. At and beyond the apex of the triangle 2 crura are united by intercrural fibers • The spermatic cord (or round ligament of the uterus) passes through this opening and carries the external spermatic fascia (or the external covering of the round ligament of the uterus) from the margins of the ring • As the spermatic cord (or round ligament of the uterus) passes under the lower border of the internal oblique, it carries with it some of the muscle fibers that are called the Cremaster muscle (fibers).

29. Roof Superficial inguinal ring Anterior wall Floor Here are the anterior wall (which has the SUPERFICIAL inguinal ring situated medially), and the roof.

30. Deep inguinal ring An oval opening in the fascia transversalis situated 1.2 cm above the midinguinal point, and immediately lateral to the stem of the inferior epigastric artery Deep inguinal ring Floor

31. Inguinal Canal Location Inferior part of the anterolateral abdominal wall It is about 4cm(1.5 inches) long, and is directed downwards, forwards and medially The inguinal canal extends from the deep inguinal ring to the superficial inguinal ring Roof Posterior wall Anterior wall Floor

32. THE ANTERIOR WALL 1.In its whole extent a. Skin b. Superficial fascia c. External oblique aponeurosis 2.In its lateral one-third The fleshy fibres of the internal obliquemuscle. The ROOF : It is formed by the arched fibres of the internal oblique and transverse abdominis muscles. The posterior wallis formed by transversalis fascia (orange) throughout and the conjoint tendon mdially. The wall is particularly weak over the deep inguinal ring 1.In its whole extent a. The fascia transversalis b. The extra peritoneal tissue c. The parietal peritoneum. 2.In its medial two-thirdsa. The conjoint tendonb. At its medial end by the reflected part of the inguinal ligament.

33. Posterior wall Conjoint tendon medially Deep inguinal ring

35. Coverings of the spermatic cord

36. Content

37. Nerve Supply of Anterior Abdominal Wall Muscles • The oblique and transversusabdominis muscles are supplied by the lower six thoracic nerves and the iliohypogastric and ilioinguinal nerves (L1). • The rectus muscle is supplied by the lower six thoracic nerves. • The pyramidalis is supplied by the 12th thoracic nerve. • The nerves of the anterior abdominal wall are the anterior rami of the lower six thoracic and the first lumbar nerves. • The thoracic nerves are the lower five intercostal nerves and the subcostal nerves and the first lumbar nerve is represented by the iliohypogastric and ilioinguinal nerves, branches of the lumbar plexus. They supply the skin of the anterior abdominal wall, the muscles, and the parietal peritoneum. • The lower six thoracic nerves pierce the posterior wall of the rectus sheath to supply the rectus muscle and the pyramidalis (T12 only). • They terminate by piercing the anterior wall of the sheath and supplying the skin.

39. The first lumbar nerve has a similar course, but it does not enter the rectus sheath. • It is represented by the iliohypogastric nerve, which pierces the external oblique aponeurosis above the superficial inguinal ring, • and by the ilioinguinal nerve, which emerges through the ring. • They end by supplying the skin just above the inguinal ligament and symphysis pubis.