Inguinal canal

Inguinal canal

1. INGUINAL CANAL AND HERNIA

2. Inguinal Canal Position: oblique passage, 4cm long, located 1.5cm above medial half of inguinal ligament

3. . ASIS PUBIC TUBERCLE INGUINAL LIGAMENT

4. INGUINAL CANAL This is an oblique intermuscular passage in the lower part of the anterior abdominal wall , situated just above the medial half of the inguinal ligament . Length and direction : It is about 4 cm long , and is directed downwards, forwards and medially . The inguinal canal extends from:- The deep inguinal ring to the superficial inguinal ring .

5. . The deep inguinal ring is an oval opening in the fascia transversalis , situated 1.2 cm above the midinguinal point. The superficial inguinal ring is a triangular gap in the external oblique aponeurosis. The base is formed by the pubic crest. Lateral/ lower margin, medial/ upper margin of the triangle. It is 2.5 cm long and 1.2 cm broad at the base. These margins are referred to as crura .

6. (a) Superficial and deep inguinal rings, (b) formation of the roof of inguinal canal, and (c) anterior and posterior walls of inguinal canal

7. Boundaries of Inguinal Canal Anterior wall External oblique aponeurosis Internal oblique aponeurosis Posterior wall Transversalis fascia Conjoint tendon (falx inguinalis)

8. Boundaries of Inguinal Canal Roof Internal oblique abdominis Transversus abdominis Floor Inguinal ligament Lacunar ligament

9. (a) Superficial and deep inguinal rings, (b) formation of the roof of inguinal canal, and (c) anterior and posterior walls of inguinal canal

10. Structures passing through the inguinal canal In males Spermatic cord Ilioinguinal nerve In females Round ligament of uterus Ilioinguinal nerve Sex Difference The inguinal canal is larger in males than in females

11. Constituents of the Spermatic Cord The ductus deferens. The testicular and cremasteric arteries , and the artery of the ductus deferens. The pampiniform plexus of veins . Lymph vessels from the testis The genital branch of the genitofemoral nerve , and the plexus of sympathetic nerves around the artery to the ductus deferens and visceral afferent nerve fibres. Remains of the processus vaginalis.

12. Transverse section through the spermatic cord

13. Coverings of Spermatic Cord 1. The external spermatic fascia derived from the external oblique 2.The cremasteric fascia and muscles :- derived from the internal oblique & transversus abdominis 3. The internal spermatic fascia :- derived from the fascia transversalis Covers the cord in its whole length

14. Covering of spermatic cord

15. MECHANISM OF INGUINAL CANAL The presence of the inguinal canal is a cause of weakness in the lower part of the anterior abdominal wall. This weakness is compensated by :- Obliquity of the inguinal canal: the two rings do not lie opposite to each other . When the intra abdominal pressure rises the anterior & posterior walls of the canal are approximated, thus obliterating the passage . Known as FLAP VALVE mechanism

16. . 2. The superficial inguinal ring is guarded from behind by the conjoint tendon 3. The deep inguinal ring is guarded from the front by the fleshy fibres of the internal oblique Shutter mechanism of the internal oblique: This muscle has a triple relation to the inguinal canal. It forms the:- anterior wall, the roof, and the posterior wall of the canal . When it contracts the roof is approximated to the floor, like a shutter.

17. 5. Contraction of the cremaster helps the spermatic cord to plug the superficial inguinal ring ( ball valve mechanism ). Contraction of the external oblique and its intercrural fibres results in approximation of the two crura of the superficial inguinal ring ( slit valve mechanism ). When there is rise in intra abdominal pressure as in coughing, sneezing, lifting heavy weights all these mechanisms come into play, so that the inguinal canal is obliterated, its openings are closed and herniation of abdominal viscera is prevented .

18. CLINICAL ANATOMY Hernia is a protrusion of any of the abdominal contents through any of its walls . This is called external hernia . At times the intestine or omentum protrudes into the “no entry” zone within the abdominal cavity itself . The condition is called as internal hernia .

19. Hernia consists of sac, contents and coverings. Sac is the protrusion of the peritoneum neck, the narrowed part; body, bigger part. 2 . Contents are mostly long mobile, keen to move out, coils of small intestine or any other viscera 3. Coverings: layers of abdominal wall which are covering the hernial sac.

20. Complications Irreducibility :- the loop of the intestine herniates out but comes back to the abdomen. Sometime, the loop goes out but does not return , leading to irreducible hernia. Obstruction :- the loop may get narrow , so that contents of the loop cannot move, leading to obstruction. Strangulation :- when the arterial supply is blocked , the loop gets necrosed.

21. Types of abdominal hernia Internal hernia Internal hernia mostly occurs in epiploic foramen External hernia • Umbilical • Paraumbilical • Femoral • Inguinal • Epigastric • Divarication of recti • Incisional • Lumbar

22. Umbilical hernia (congenital umbilical hernia) Due to non- return of midgut loop back to the abdominal cavity

23. Acquired infantile umbilical hernia Due to weakness of umbilical scar, a part of gut may be seen protruding out.

24. Para umbilical hernia Loop of intestine protrude through the linea alba around the region of umbilicus

25. Femoral hernia it occurs more in female, due to larger pelvis, smaller blood vessels & larger femoral canal

26. Inguinal hernia : protrusion of the loop of intestine through the inguinal wall or inguinal canal . Indirect/ oblique inguinal hernia when the protrusion occurs through the deep inguinal ring, inguinal canal, superficial inguinal ring into the scrotum. Occurs in male infants, children & has narrow neck of the hernial sac Direct inguinal hernia when the protrusion occurs through the weak posterior wall of the inguinal canal/ triangle of Hesselbach Occurs in much older men Has wider neck of hernial sac Divided into medial & lateral parts by the passage of obliterated umbilical artery

27. . Epigastric hernia: It occurs through the upper part of wide linea alba Divartication of recti : Occurs in multiparous (given birth more than once) female, with weak anterolateral abdominal muscles

28. Thank you