Anatomy

1. PRESENTED BY : SUNTOO IRMA
ROLL NO : 102
DATE : 21/09/12
ANTEROLATERAL ABDOMINAL
WALL.

2. Table of Content
 Introduction to Abdomen
 Abdominal wall
 Anterolateral muscles
 Innervation
 Arterial supply &Venous drainage
 Lymphatic drainage
 Applied
 References

3. • The abdomen is the part of the trunk inferior
to the thorax.
• Its musculomembranous walls surround a
large cavity, which is bounded
superiorly by the diaphragm &
inferiorly by the pelvic inlet.

4. Abdominal wall
 Bounded superiorly by : xiphoid process &
costal margins.
 Posteriorly by : vertebral column.
 Inferiorly by : upper parts of pelvic bones.

5. Anterolateral Muscles
o There are 5 muscles in the anterolateral
group of abdominal wall muscles.
o 3 flat muscles whose fibres begin
posterolaterally, pass anteriorly, & are
replaced by an aponeurosis as the muscle
continues towards the midline.
1. External oblique
2. Internal oblique
3. Transversus abdominis

6. o 2 vertical muscles, near the mildline which
are enclosed within a tendinous sheath
formed by aponeuroses of flat muscles.
1. Rectus abdominis
2. Pyramidalis.

7. 1. External oblique muscle:
 Most superficial out of the three flat muscles.
 Immediately superficial to superficial
fascia.
 Its laterally placed muscle fibres pass in an
inferomedial direction,while its large
aponeurotic component covers the anterior part
to the midline.
 At the midline, aponeuroses are entwined
forming the linea alba, which extends from
xiphoid process to pubic symphysis.

8. 2. Internal oblique muscle
 Deep to external oblique muscle.
 2nd of the 3 flat muscles.
 Most of its muscle fibres pass in a
superolateral direction.
 Its lat muscular components end anteriorly as
an aponeurosis that blends into linea alba at
the midline.

9. 3. Transversus abdominis
 Deep to internal oblique.
 Ends in an anterior aponeurosis, which blends
with the linea alba at the midline.
Transversalis fascia
Each of the three flat muscles is covered on
the ant & post surfaces by a layer of deep
fascia. Only the layer deep to the
transversus abdominis is remarkable.

10. Vertical muscles
1. Rectus abdominis
 long, flat muscle and extends the length of the
anterior abd wall.
 It is a paired muscle, separated in the midline by
linea alba.
 It widens & thins as it ascends from the pubic
symphysis to costal margin.

11. 2. Pyramidalis muscle
 2nd vertical muscle.
 This small, triangular muscle which may be
absent, is anterior to the rectus abdominis,
has its base on the pubis, and apex is
attached superiorly & medially to the linea
alba.

12. Rectus Sheath
 Aponeurotic sheath covering the rectus
abdominis.
 Completely encloses the upper ¾ of rectus
abdominis & covers the anterior surface of
lower ¼ of the muscle
 The posterior surface of lower quarter of
rectus abdominis is in direct contact with the
transversalis fascia.

13. Innervation
 The skin, muscles and parietal peritoneum of
the anterolateral abdominal wall are supplied
byT7 toT12 and L1 spinal nerves.
 NervesT7 toT9 supply skin from xiphoid
process to just above umbilicus.
 T10 supplies skin around umbilicus.
 T11,T12 &L1 supply skin from just below the
umbilicus to, and including the pubic region.

14. Arterial supply & venous
drainage.
Superficially :
1) Musculophrenic artery
2) Superficial epigastric artery
& Superficial circumflex iliac.
At a deeper level :
1) Sup. Epigastric artery
2)10th & 11th intercostal
arteries & subcostal artery
3) Inf. Epigastric artery
Veins of similar names are reponsible for
venous drainage.

15. Lymphatic drainage
 Superficial lymphatics :
1) Axillary nodes
2) Superficial inguinal nodes
 Deep lymphatic drainage follows the deep
arteries back to parasternal nodes along with
internal thoracic artery.

16. Applied.
1) Umbilical hernia :
 Congenital.
Due to non-return of midgut loop back to
the abdominal cavity.

17. 2)Acquired infantile umbilical
hernia.
 Due to weakness of umbilical scar, a part of
the gut may be seen protruding out. It
disappears as the infant grows.

18. 3) Paraumbilical hernia
 Loop of intestine protrude through the linea
alba around the region of umbilicus.

19. 4) Femoral hernia
 Occurs more in females due to larger pelvis,
smaller blood vessels and larger femoral
canal.
 Surgery is essential for its treatment.

20. 5) Epigastric hernia
 Occurs through the upper part of wide linea
alba.

22. 6) Incisional hernia
 Occurs through the anterolateral abdominal
wall when incisions are made for the surgery,
involving cutting of spinal nerves.

23. •Internal Hernia
 Remnants of the vitellointestinal duct may
form a tumour at the umbilicus (raspberry red
tumour)
 Persistance of a patent vitellointestine duct
results in a faecal fistula at the umbilicus.

24. Ventral hernia
 Supraumbilical median incisions through
the linea alba have various advantages
as being
1) Bloodless
2) Safety to muscles & nerves
However, It tends to leave a
postoperative weakness through which
a ventral hernia may develop.

25. Infraumbilical Median Incision
 Safer, because the close approx. of recti
prevents formation of any ventral hernia.
 Paramedian incisions are more sound than
median incisions.
 The rectus muscle is retracted laterally to
protect the nerves supplying it from any
injury.

26. References:
 GRAY’S ANATOMY.
 Wikipedia.
 B D Chaurasia’s Human Anatomy.