Anterolateral Abdominal Wall

Question 1

Boundaries and Layers

Answer 1

Boundaries:
* Superiorly: xiphoid process & costal margins
* inferiorly: upper parts of pelvic bone
* Posterior: thoracolumbar fascia/lumbar vertebrae

Layers
* skin
* superficial fascia: 1. camper’s fascia 2. scarpa’s fasica
* muscles & their associated fascias: 3. exernal oblique, 4. internal oblique, 5. transversus abdominis
* 6. transversalis & 7. extraperitoneal fascia
* 8. parietal peritonium

Question 2

Superficial fascia

Answer 2

Subcutaneous tissue in abdomen:
* is a layer of fatty CT
* similar to and continous with the superficial fascia of other regions of the body

However
* roughly at the level of the umbilicus it forms 2 layers
* superficial fatty layer: camper’s, contains fatty & varies in thickness
* deep membranous layer: scarpa’s
-thin & membranous
-contains little to no fat
-inferiorly it continues into the thigh. Below the inguinal lig, it fuses with the fascia lata
-in the middle it is attached to the linea alba & symphysis of pubis

In men:
* continues in the penis
* after losing its fat it fuses with the deeper layer (scarpa’s) of superficial fascia
* continues in the scrotum where it forms a specialized fascial layer containing smooth muscle fibers (dartos fascia)

In women:
* retains some fat and is a component of the labia majora

Question 3

Anterolateral muscles

Answer 3

5 muscles in the anterolateral group:
3 flat muscles:
* external oblique
* internal oblique
* transversus abdominus
* the fibers begin posterolaterally, pass anteriolrly & are replaced by an aponeurosis as the muscle continues towards the midline

2 vertical muscles:
* rectus abdominis
* pyramidalis
* near the midline and enclosed by the apeneuroses of the flat muscles

Question 4

Transveralis & extraperitoneal fascias

Answer 4

Transversalis fascia
* thin aponeurotic membrane
* between the inner surface of the transverse abdominis & the extraperitoneal fascia

Extraperitoneal fascia
* deep to the transversalis fascia
* seperated the transversalis fascia from the peritoneum

Question 5

Rectus Sheath

Answer 5

• encloses the rectus abdominis & pyramidalis
• formed by: aponeuroses of the external & internal oblique & transversus abdominis miscles

Question 6

Ligaments

Answer 6

Inguinal ligament
* formed by lower border of the oblique aponeurosis
* passes between the ASIS & pubic tubercle

Lacunar ligament
* crescent-shaped extension of fibers at the medial end of the inguinal lig
* attach to the pectin pubis on the superior ramus of the pubic bone

Pectineal ligament
* extension of the lacunar lig along pectin pubis line

Together make a V at the pubic tubercle

Question 7

Inguinal canal & contents

Answer 7

• slit like passage
• located just above & parallel to the inguinal ligament
• beings in the deep inguinal ring ends at the superficial inguinal ring

contents:
* spermatic cord in men–consists of structures passing between abdominopelvic cavities & testis:
-atery of ductus deferens
-testicular artery
-testicular veins
-sympathetic & afferent nerve fibers
-lymphatics
* round ligament of the uterus in woman
-cord like structure passes from the uterus to deep inguinal ring entering inguinal canal
-after exiting the superficial inguinal ring, it changes from a cord like structure to a few strands of tissue. Attached to a CT associated with the labia majora
-function: maintanence of the anteroflexion of the uterus. Fundus of the uterus is turned forward at the junction of cervix.
* these structures enter the inguinal canal through deep ring & exit thrrough superficial inguinal ring

Question 8

Inguinal hernias

Answer 8

is the protrusion or passage of the peritoneal sac through a weakened part of the abdominal wall in the groin

The peritoneal sac enyers the inguinal canal either
* directly: through posterior wall of the inguinal canal
* indirectly: through deep inguinal ring

Question 9

Vessels of anterolateral abdominal wall

Answer 9

Upper: branches from internal thoracic artery
* intercostal arteries
* musculophrenic artery
* superior epigastric artery

Lower:
* superficial circumflex liliac artery–branch from femoral artery
Branches from external iliac artery:
* inferior epigastric artery
* deep circumflex iliac artery