The document discusses the anatomy of the anterolateral abdominal wall. It describes the five muscles that make up the anterolateral wall - the external oblique, internal oblique, transversus abdominis, rectus abdominis, and pyramidalis. It details the structure, function and innervation of these muscles. The document also discusses the blood supply, lymphatic drainage and applied clinical considerations like different types of hernias related to weaknesses in the abdominal wall.

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.