Clinical aspect of anterior abdominal wall
Surface markings and anatomy
Regions of abdomen 1 hypochrondriac (r,l) 2 lumbar (flank-r, l) 3 paraumbilical 4 Iliac (iliac fossa, r, l)) 5 suprapubic (hypogastric) 6 epigastric 7 left lateral line or midclavicular line 8 transpyloric plane (L1) 9 subcostal plane 10 transtubercular plane (L5)
Surface markings of abdominal organs
Neck lies at the level of transpyloric plane
Anterior abdominal wall
This is the gateway to the abdominal cavity anteriorly. It exposes the true intraperitoneal structures such as the small intestine, stomach, distal duodenum, transverse colon and sigmoid colon
It is provided with the following layers
2. Superficial fascia
3. THERE IS NO DEEP FASCIA
4. Layer of muscles which are arranged in three strata
a. External oblique muscle of abdomen
b. Internal oblique muscle of abdomen
c. Transversus abdominis
The three layers correspond to the three layers of muscles in the intercostal spaces which are the external intercostal, internal intercostals and innermost intercostals muscles
5. Transversalis fascia
6. Parietal peritoneum
A hernia is an abnormal protrusion through a normal or abnormal space or opening. In the case of the inguinal hernia, it is an abnormal protrusion through the normal inguinal canal opening. It may be congenital and if so, it may extend through the embryological processus vaginalis into the scrotal sac forming the so called congenital inguino-scrotal hernia.
The inguinal canal is formed as an oblique opening through the muscles of the anterior abdominal wall. It extends from the superficial inguinal ring (external oblique aponeurosis) to the deep inguinal ring (transversalis fascia). It is about 4cm long. The hernia is usually a viscus, such as small or large intestine, urinary bladder, appendix, omentum etc. It passes through the deep inguinal ring acquiring the similar covering of internal spermatic fascia. It also acquires the covering of cremasteric fascia in the inguinal canal. In order to separate it therefore from the spermatic cord, the line of cleavage with the above fasciae must be sought for. It may extend from the deep inguinal ring to the superficial inguinal ring, in which case it is called the indirect or oblique hernia. If it enters through the posterior wall made up of conjoint tendon (medially) and transversalis fascia (laterally), it is called a direct hernia.
A hernia is repaired by removing the hernial sac after the reduction of the hernia and then reconstructing the inguinal canal using stitches that reduce its size.
Other types of hernia exist in the anterior abdominal wall. All anterior abdominal wall hernias are said to be external hernias as opposed to the internal hernias which occur in the peritoneal and other cavities of the body.
Other external hernia includes
Interstitial hernia (passes through the muscle fibers )
Epigastric hernias – through linea alba above the umbilicus
Lumbar hernia (found a the lumbar triangle)
.Blood supply to the anterior abdominal wall
Electronic School of Medicine
Creator: Oluwole Ogunranti