Anterior Abdominal wall and facial lining of abdomen.

2. Structure of Anterior
Abdominal wall
Group Members : Ahsan Javed, Sarmad Rasool,
Hassan Ali, Abdur Rehman, Tuaseen Hafeez,
Shoaib Akhtar

3. Structure of Anterior Abdominal wall
 The anterior abdominal wall is made up of :
Skin
Superficial fascia
Deep fascia
Muscles
Extraperitoneal fascia
Parietal Peritoneum

4. Skin
The skin is loosely attached to underlying structures except at the
umbilicus.
The umbilicus is a scar representing the site of the attachment of the
umbilical cord in the fetus; it is situated in the linea alba.

6. Nerve Supply to Skin
 The cutaneous nerve supply to anterior abdominal wall is derived
from the anterior rami of lower six thoracic and first lumber nerves.
 The dermatomes of T7 is located over the xiphoid process.
 The dermatomes of T10 includes the umbilicus.
 L1 lies just above the inguinal ligament and symphysis pubis.

8. Blood Supply of Skin
 The skin near the midline is supplied by the branches of superior and
inferior epigastric arteries.
 The skin of Flank is supplied by the branches of
 Intercostal arteries
 Lumbar arteries
 Deep circumflex iliac arteries

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 Veins
 The venous drainage passes above mainly into axillary vein
via the lateral thoracic vein.
&
 Below into the femoral vein via the superficial epigastric
and the great saphenous vein.

10. Superficial Fascia
 The superficial fascia is divided into
 Superficial Fatty layer ( fascia of complex)
 Deep membranous layer ( scarpa’s fascia)
 The Fatty layer is continuous with the superficial fat over the rest of
the body and may be extremely thick [8cm] or more in obese patients.
The membranous layer is thin and fades out laterally and above, where
it becomes continuous with superficial fascia of back and thorax.

11. Deep Fascia
 It is a thin layer of connective tissue covering the muscles.
 It lies immediately deep to the membranous layer of superficial
fascia.

13. Muscles
 The muscles of abdominal wall consist of three broad thin sheets.
• From Exterior to Interior they are the
External Oblique
Internal Oblique
Transversus abdominis

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 On either side of the midline anteriorly is, in addition, a wide vertical
muscle is present known as Rectus Abdominis.
 As the aponeurosis of the three sheets pass forward, they encloses the
rectus abdominis to form the Rectus Sheath.

16. 1. External Oblique
 Origin : the outer surface of lower eight ribs(5-12).
 Insertion : the xiphoid process, linear alba, pubic crest, pubic
tubercle and the anterior half of iliac crest.
 Nerve supply : lower six thoracic nerve (T7-T12), Iliohypogastric and
Ilioinguinal nerves (L1).
 Action : Supports abdominal contents, assist in flexing and rotating
of trunk, assist in forced expiration, defecation and vomiting.

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 There is a triangular shaped defect in external oblique aponeurosis
that lies immediately above and medial to the pubic tubercle known as
Superficial inguinal ring.
 The spermatic cord (or ligament of the uterus) passes through this
opening and carries the external spermatic fascia (or the external
covering of the round ligament of uterus) from the margin of the ring.

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 Between the anterior superior iliac spine and the pubic tubercle, the
ring lower border of the aponeurosis is folding backward on itself,
forming the inguinal ligament.

20. Diagram
showing location
of
Inguinal Ligament

21. 2. Internal Oblique
 Origin : lumbar fascia, the anterior two third of iliac crest and the
lateral two third of inguinal ligament.
 Insertion : the lower border of the lower three ribs and their costal
cartilages, the xiphoid process, the linea alba and symphysis pubis.
 Nerve supply : lower six thoracic nerves (T7-T12), Iliohypogastric and
Ilioinguinal nerves (L1).
 Action : Supports abdominal contents, assist in flexing and rotating
of trunk, assist in forced expiration, defecation and vomiting.

22. Diagram showing
location of
Internal Oblique

23. 3. Transversus Abdominis
Origin : the deep surface of lower six costal cartilages, the lumbar
fascia, the anterior two third of iliac crest and the lateral third of
inguinal ligament.
 Insertion : the xiphoid process, linea alba and the symphysis pubis.
 Nerve supply : lower six thoracic nerves (T7-T12), Iliohypogastric
and Ilioinguinal nerves (L1).
 Action : compresses abdominal contents.

24. Location of
Transversus Abdominis

25. 4. Rectus Abdominis
 The rectus abdominis muscle 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 linea alba.

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 Origin : symphysis pubis and pubic crest.
 Insertion : fifth, sixth and seventh costal cartilages and xiphoid
process.
 Nerve Supply : Lower sic thoracic nerves (T7-T12).
Action : compresses abdominal contents; flexes vertebral column;
accessory muscles of expiration

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 The Rectus abdominis muscles is divided into distinct segment by
three transverse tendinous intersections :
1. One at the level of xiphoid process
2. One at the level of umbilicus
3. One halfway between these two
 These intersections are strongly attached to anterior wall of rectus
sheath.

29. 5. Pyramidalis
 The Pyramidalis muscle is absent.
 Origin : anterior surface of the pubis
 Insertion : linea alba
 Nerve supply : twelfth thoracic nerve (T12)
 Action : tenses the linea alba
 It lies in the front of lower part of rectus abdominis.

31. Rectus Sheath
The rectus sheath is a long fibrous sheath that encloses the rectus
abdominis muscles and pyramidalis muscle (if present).
It is formed mainly by the aponeurosis of three lateral abdominal
muscles.

33. Transversalis fascia
 The fascia transversalis is a thin layer of fascia that lines the
transversus abdominis muscles.
 It is continuous with a similar layer lining the Pelvic muscles.
 For Example :
 Diaphragmatic fascia covers the diaphragm.
 Transversalis fascia lines the transversus abdominis.
 Iliac fascia covers the iliacus muscle.

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 The abdominal blood and lymph vessels lie within this fascial lining,
whereas the femoral sheath lie outside the fascia.
 Femoral sheath is a funnel shaped sheath, derived from transversalis
fascia anteriorly and iliac fascia posteriorly.
 It surround the femoral vessels and lymphatic and about 2.5cm below
the inguinal ligament.

36. Extraperitoneal Fascia
 Extraperitoneal Fascia is a thin layer of connective tissue that
contains a variable amount of fat.
 It lies between the transversalis fascia and the parietal peritoneum.

38. Parietal Peritoneum
 The walls of abdomen are lined with parietal peritoneum.
 This is a thin serous membrane and is continuous below with the
parietal peritoneum lining the pelvis.