The Abdominal Wall - Muscles of the Trunk

1. The Abdominal WallThe Abdominal Wall
Muscles of the Trunk Muscles of the Trunk
Raymond G Buick FRCS

2. Muscles of the Trunk
•large cavity
•bounded by
–posterior abdominal wall
–diaphragm
–anterior abdominal wall
–pelvic floor

3. Layers of Abdominal Wall
•antero-lateral wall of abdomen
•several layers
–skin
–s/c tissue – a superficial fat and fascial layer
–muscles
–transversalis fascia
–extraperitoneal fat
–parietal peritoneum

4. Layers of Abdominal Wall
–s/c tissue – a superficial fat and fascial layer
•2 layers
Camper’s fascia – thick, fatty layer
Scarpa’s Fascia - deeper fascial layer

5. Layers of Abdominal Wall
–s/c tissue – a superficial fat and fascial layer
thick
fatty layer
continuous with
superficial. fascia of thigh
Camper’s FasciaCamper’s Fascia
dartos muscle
no fatty tissue
involuntary muscle fibres
pale reddish in colour

6. Layers of Abdominal Wall
–s/c tissue – a superficial fat and fascial layer
deeper
thinner layer
membranous
large amount of yellow elastic fibres
blends with fascia lata
of thigh
Scarpa’s FasciaScarpa’s Fascia
helps form
dartos muscle

7. Muscles of the Trunk
–muscles
•4 paired muscles

8. Muscles of the Trunk
•3 paired flat muscles + strap muscles
–external oblique
–internal oblique
–transversus abdominis

9. Muscles of the Trunk
•3 paired flat muscles + strap muscles
–external oblique - rectus abdominis
–internal oblique
–transversus abdominis

10. Muscles of the Trunk
3 paired muscles
rectus abdominis

11. Layers of Abdominal Wall
•antero-lateral wall of abdomen
•several layers
–skin
–s/c tissue – a superficial fat and fascial layer
–muscles
–transversalis fascia
–extraperitoneal fat
–parietal peritoneum

12. Layers of Abdominal Wall
transversalis fascia (or transverse fascia)
•is a thin aponeurotic membrane
•thick and dense in structure inferiorly and
thins out as it ascends to the diaphram
•deep to transversus abdominis muscle
•superficial to extraperitoneal fat and parietal
peritoneum

13. Layers of Abdominal Wall
extraperitoneal fat
variable with age and location
•most apparent in the falciform ligament
below the upper part of the linea alba

14. Muscles of the Trunk
3 paired muscles
–external oblique
–internal oblique
–transversus abdominis

15. Muscles of the Trunk
3 paired muscles
–laterally
lower ribs
lumbodorsal fascia
iliac crest
inguinal ligament

16. Muscles of the Trunk
3 paired muscles
–medially
aponeurosis

17. Muscles of the Trunk
3 paired muscles
–medially
linea alba

18. Aponeurosis
•A sheetlike fibrous membrane resembling a flattened tendon
that serves as a fascia to bind muscles together (or to connect
muscle to bone).
•shiny, whitish-silvery colour,
•histologically similar to tendons
•few blood vessels and nerves
•pleural: aponeuroses

19. external oblique
external obliqueexternal oblique

20. external oblique
external obliqueexternal oblique

21. external oblique
external obliqueexternal oblique

22. external oblique
external obliqueexternal oblique

23. external oblique
external obliqueexternal oblique
aponeurosisaponeurosis

24. external oblique
•inguinal ligament
–ant. sup. iliac spine
–pubic tubercle

25. internal oblique
internal obliqueinternal oblique

26. transversus abdominis
transversus transversus
abdominisabdominis

27. transversus abdominis
transversus transversus
abdominisabdominis

28. external obliqueexternal oblique
3 flat muscles

29. external obliqueexternal oblique
internal obliqueinternal oblique
3 flat muscles

30. external obliqueexternal oblique
internal obliqueinternal oblique
transverse abdoministransverse abdominis
3 flat muscles

31. rectus abdominis
rectus rectus
abdominisabdominis

32. rectus abdominis
tendinous intersectionstendinous intersections

33. an additional muscle
PyramidalisPyramidalis

34. Muscles of the Trunk
PyramidalisPyramidalis

35. Rectus Sheath

36. Rectus Sheath
level of
arcuate line
linea semicircularis

37. Rectus Sheath – upper
3
/
4
transversus transversus
abdominisabdominis
internal obliqueinternal oblique
external obliqueexternal oblique
transversalis fasciatransversalis fascia
peritoneuperitoneu
mm
linea albalinea alba
extraperitoneal extraperitoneal
fatfat
skinskin
s/c s/c
tissuetissue

38. Muscles of the Trunk
transversus transversus
abdominisabdominis
internal obliqueinternal oblique
external external
obliqueoblique
transversalis fasciatransversalis fascia
peritoneumperitoneum
upper three quarters lower quarter

39. arcuate line
linea semicircularis
or Douglas' line

40. SpigelianSpigelian
HerniaHernia

41. The EndThe End
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