1. Anterior abdominal wall

2. Layers of Anterior Abdominal Wall
In human anatomy, the layers of the abdominal wall are (from superficial to deep):
Skin
Fascia
Camper's fascia - fatty superficial layer.
Scarpa's fascia - deep fibrous layer.
Muscle
-Rectus abdominis
-External oblique muscle
-Internal oblique muscle
-Transverse abdominal muscle
Pyramidalis muscle
Cremasteric
Fascia transversalis
Parital Peritoneum

3. Fascia of Ant. Abdominal Wall
1- there is no deep fascia
2-the superficial fascia is formed of a single layer above the ambilicus , but below the ambilicus it differentiated into 2 layers:
a- superficial fatty layer (Camper’s fascia)
- contains variable amount of fat .
b- deep membranes layer (Scarpa’s fascia)
-continuous with the superficil perineal fascia (colle’s fascia)

4. Linea Alba
An extensive aponeurosis which extend from the xiphoid process to the symphsis pubis .
Linea Semilunaris
the lateral margin of rectus abdominis is marked by a line on the anterior abdominal wall called linea semilunaris

5. Muscles of the anterior abdominal wall
Classified into 2 groups:
1- paramedian muscles
-Rectus abdominis muscle
- Pyramidalis muscle
2- anterolateral flat muscles
-external abdominal oblique m.
-internal abdominal oblique m.
-transversus abdominis m.

6. Abdominal external oblique muscle
the largest and the most superficial of the three flat muscles of the lateral anterior abdomen.

7. Direction of the fibers :
Origin :
lower 8 ribs (outer surface)
Direction of the fibers :
downwards , forwards & medialy
Insertion :
-iliac crest ( anterior half of the outer lip)
-anterior superior iliac spine
-pubic tubercle
-pubic crest
-linea alba
………………………….

8. Inguinal ligament
-It is the infolded lower border of the external oblique m.
-The inguinal ligament runs from the anterior superior iliac spine to the pubic tubercle.

9. Abdominal internal oblique muscle
Origin :
1- iliac crest (ant. 2/3 of its intermediate line)
2- inguinal ligament
( lateral 2/3 of its inner surface).
3- lumbar fascia .
Direction of the fibers :
upwards , forwards and medialy
Insertion :
1- linea alba
2- lower 4 or 5 ribs
3- the lower fibers forms an arched fibers called the conjoint tendon.

10. Conjoint tendon
-Formed by the lower arched fibers of both internal oblique and transversus abdominis muscles where the fiberous pass directly from origin to insertion
-Function :
The contraction of the conjoint tenden leads to closure of the inguinal canal
(shutter mechanism )
-So , it prevent passage of intestine through the canal (Indirect inguinal hernia) .

11. Transversus abdominis muscle
Origin :
-the lateral third of the inner surface of inguinal ligament
-anterior 2/3 of the medial lip of the iliac crest
-the inner surfaces of the cartilages of the lower 8 ribs
-the thoracolumbarl fascia.
Direction of the fibers :
-horizontaly .
Insertion:
a- linea alba
b-the lower fibers form an arched fibers together with the lower fibers of internal oblique muscle (conjoint tendon)

13. Rectus abdominus m. Site :
it lies in the middle part of the abdominal muscle layer inside the tendinous sheath called rectus sheath.
Origin :
symphysis pupis and pubic crest.
Insetion:
5th, 6th & 7th costal cartilages-
-The muscle is divided by 3 tendinous intersections as follows:
-These tendentious intersections are present on the anterior surface of the muscle and indicate that the muscle arises from different myotomes .

14. Action :
-flexion of the trunk .
Surface anatomy :
the lateral margin of rectus abdominis is marked by aline on the anterior abdominal wall called linea semilunaris .

15. Pyramidalis muscle : pubic crest and symphysis pubis Insertion :
Origin :
pubic crest and symphysis pubis
Insertion :
into the lower part of the linea alba
Nerve supply :
subcostal nerve
Action :
it stretches the linea alba

16. Rectus Sheath
Definition: is a long fibrous sheath that encloses the rectus abdominis muscle and pyramidalis muscle (if present).
Contents of rectus sheath:
Anterior rami of the lower six thoracic nerves
Superior and inferior epigastric vessels
Lymph vessels.
Rectus abdominis and pyramidalis ms.
It is formed mainly by:
The aponeuroses of the three lateral abdominal muscles

17. Pattern of the Rectus Sheath Formation
The rectus sheath surrounding the upper ¾ of the rectus abdominis muscle:
The anterior wall consists of : the aponeurosis of the external oblique and anterior layer of the aponeurosis of the internal Oblique.
The posterior wall of the rectus sheath consists of: the aponeurosis of the internal oblique and the aponeurosis of the transversus abdominis.

18. The rectus sheath surrounding the lower ¼ of the rectus abdominis muscle(midway between the umbilicus and the pubic symphysis):
The anterior wall of the sheath consists of: the aponeuroses of the external oblique, the internal oblique, and the transversus abdominis muscles
The posterior wall of the rectus sheath consists of: transversalis fascia (the arcuate line).

19. Cremastric muscle: action: Cremastric reflex:
It is formed by loops of muscle fibres from the lower part of the internal oblique
it extends down through the spermatic cord & return behind it to be attached to the pubic tubercle
its n. supply is the genital branch of the genitofemoral n.
action:
elevation of testis upwards in the cold weather.
Cremastric reflex:
Scratching of the upper & medial parts of the thigh (L1) leads to elevation of the testis.

20. Action of the anterior abdominal wall muscles
1-support the viscera and keep them in their position
2-contract to increase the intra-abdominal pressure during urination and defection (mainly the trunsversus abdominis).
3-expiratory action :
-the abdominal muscles contract during expiration and relax during inspiraion .
4-movement of the trunk :
a-contraction of rectus abdominis muscle ……..forward flexion.
b-contraction of one side of the oblique muscles ……….lateral flexion .
c. combined action of external oblique with the oppisite internal oblique ……rotation of the trunk .
5- elevation of the testis ………..by the cremastric m .

21. Inguinal canal Definition: Openings:
It is an oblique inter-muscular canal (4cm) above the medial part of the inguinal ligament.
Openings:
-it starts at the deep inguinal ring and ends at the superfascial inguinal ring.

22. a-Superfascial Inguinal Ring
Site:
it is a triangular or inverted V shaped opening in the external oblique aponeurosis.
its margins give the external spermatic fascia to cover the spermatic cord.
Surface anatomy:
It lies just above the pupic tubercle.
Structures passing through it:
-illio-inguinal nerve.
-Spermatic cord ( in male) or round ligament ( in female)

23. B -Deep Inguinal Ring Site: Surface anatomy:
It is a small opening in the lower part of fascia transversalis.
Its margins give the internal spermatic fascia to cover the spermatic cord.
Surface anatomy:
- It lies ½ an inch above the mid-point of the inguinal ligament.
Structures passing through it:
-Spermatic cord (in male) or round ligament ( in female).

24. Arteries of the Anterior Abdominal wall A- Above the umbilicus
1-superior epigastric artery
2-musculo-phrenic artery
3-lower two posterior intercostal and subcostal arteries

25. B- Below the umbilicus 1-Inferior epigastric artery
2-Deep circumflex iliac artery
3-Superficial branches of femoral artery

26. Veins of Anterior Abdominal Wall
The anterior abdominal wall is drained by veins corresponding to the arteries

27. Nerves of the Anterior Abdominal Wall
1-Lower five intercostal and subcostal nerves
2-Illio-hypogastric and illio-inguinal nerves
…………………..

29. Lymphatics of Anterior Abdominal Wall
A-Above the umbilicus into pectoral lymph nodes
B- Below the umbilicus into superficial inguinal lymph nodes
……………

30. Thank You