Abdominal Wall Anatomy

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Questions and Answers

What is the clinical importance of the inguinal region?

It serves as a region of potential weakness in the abdominal wall, and thus a common site of herniation.

Where are the inguinal canals located?

In the inguinal region, which extends from the lower abdomen into the medial part of the proximal thighs on each side.

How long is the inguinal canal in an adult?

3-5 cm

Where is the deep inguinal ring located?

At the midpoint of the inguinal ligament, and 1.25 cm above the mid-inguinal point. Signup and view all the answers

What borders the superficial inguinal ring?

The inferolateral border of rectus abdominis, inferior epigastric vessels, and medial third of the inguinal ligament. Signup and view all the answers

What is the deep inguinal ring?

An oval opening in the transversalis fascia. Signup and view all the answers

What is the superficial inguinal ring?

A V-shaped opening in the external oblique aponeurosis. Signup and view all the answers

Why is the inguinal canal more developed in males?

To accommodate the passage of the testes into the scrotal sac. Signup and view all the answers

How is the anterolateral abdominal wall divided to describe the location of abdominal organs and the pain associated with them?

Into four quadrants and nine segments Signup and view all the answers

What are the names of the four quadrants of the abdominal wall?

Right upper, left upper, right lower, and left lower quadrants Signup and view all the answers

How are the nine abdominopelvic regions/segments divided horizontally?

By the superior subcostal plane and the inferior intertubercular plane Signup and view all the answers

What are the names of the two regions superiorly in the abdominal wall?

Hypochondriac (right, left) and epigastric regions Signup and view all the answers

What is the most superficial layer of the anterior abdominal wall?

The skin Signup and view all the answers

What are the two layers of the superficial fascia inferior to the umbilicus?

Camper's fascia and Scarpa's fascia Signup and view all the answers

What is Camper's fascia?

A thicker fatty layer of the superficial fascia Signup and view all the answers

What is the purpose of dividing the abdominal wall into quadrants and segments?

To describe the location of abdominal organs and the pain associated with them Signup and view all the answers

What is a hernia defined as?

the protrusion of an organ or fascia through the wall of a cavity that normally contains it Signup and view all the answers

What forms the side walls of the superficial ring?

Aponeurotic crura of the external oblique Signup and view all the answers

What is the difference between indirect and direct inguinal hernias?

Indirect inguinal hernia: peritoneal sac enters through the deep inguinal ring; Direct inguinal hernia: peritoneal sac enters through the posterior wall of the inguinal canal Signup and view all the answers

What reinforces the lateral crus of the external oblique?

The inguinal ligament Signup and view all the answers

Why do indirect inguinal hernias occur?

failure of the processus vaginalis to regress Signup and view all the answers

What is a pantaloon hernia?

a hernia that occurs through both the deep and superficial rings at the same time Signup and view all the answers

What is the roof of the inguinal canal composed of?

Transversalis fascia, internal oblique, and transversus abdominis Signup and view all the answers

What is the purpose of the muscles of the anterior and posterior walls contracting during periods of increased intra-abdominal pressure?

To prevent herniation of the viscera into the canal Signup and view all the answers

What is an incarcerated hernia?

a hernia that is no longer reducible Signup and view all the answers

What are the contents of the inguinal canal in males?

Spermatic cord and ilioinguinal nerve Signup and view all the answers

What is a strangulated hernia?

a hernia that contains a non-viable bowel that can become necrotic, possibly infected, and may perforate if not treated Signup and view all the answers

What are the symptoms of a strangulated hernia?

severe pain and signs of septic shock Signup and view all the answers

How does the ilioinguinal nerve enter the scrotum?

Through the superficial ring Signup and view all the answers

What are the three types of fascia that make up the spermatic cord?

External spermatic, cremasteric, and internal spermatic Signup and view all the answers

What can happen if a hernia is left untreated?

it can become incarcerated and eventually strangulated Signup and view all the answers

What nerve is responsible for providing sympathetic fibers to the spermatic cord?

Genital branch of the genitofemoral nerve Signup and view all the answers

What is the superior recess of the lesser sac bordered by?

The diaphragm and the coronary ligament of the liver Signup and view all the answers

What is the epiploic foramen of Winslow located?

Posterior to the free edge of the lesser omentum Signup and view all the answers

What are the boundaries of the epiploic foramen?

Anterior - hepatoduodenal ligament, Posterior - inferior vena cava and the right crus of the diaphragm, Superior - caudate lobe of the liver, Inferior - superior part of the duodenum Signup and view all the answers

What are the two compartments of the greater sac?

Supracolic compartment and infracolic compartment Signup and view all the answers

What is the supracolic compartment located in relation to the transverse mesocolon?

Anterior and superior Signup and view all the answers

What is the infracolic compartment divided into?

Right and left infracolic spaces Signup and view all the answers

What is the function of the mesentery?

To hold organs in place from the back wall of the abdomen Signup and view all the answers

What are omenta?

Two layers of peritoneum that have fused Signup and view all the answers

Study Notes

Abdominal Wall

The anterolateral abdominal wall is divided into four quadrants and nine segments to describe the location of abdominal organs and associated pain.
The four quadrants are divided by the horizontal transumbilical and vertical median planes.
The nine abdominopelvic regions/segments are divided by the superior subcostal plane, inferior intertubercular plane, and two midclavicular planes.
The regions include: hypochondriac, epigastric, flanks, umbilical, inguinal, and hypogastric regions.

Skin and Superficial Fascia

The skin is the most superficial layer of the anterior abdominal wall.
The superficial fascia is located just below the skin and consists of connective tissue.
Inferior to the umbilicus, the superficial fascia is divided into two layers: Camper's fascia (fatty superficial layer) and Scarpa's fascia (deep layer).
Camper's fascia is a thicker fatty layer that can have a variable degree of thickness and serves as a region of potential weakness in the abdominal wall.

Inguinal Canal

The inguinal canal is located in the inguinal region, which extends from the lower abdomen into the medial part of the proximal thighs on each side.
The canal ranges from 3-5 cm long in an adult and originates superolaterally at the deep inguinal ring.
The deep inguinal ring is located 1.25 cm above the mid-inguinal point and is an oval opening in the transversalis fascia.
The superficial inguinal ring is bordered medially by the inferolateral border of rectus abdominis, laterally by the inferior epigastric vessels, and inferiorly by the medial third of the inguinal ligament.
The inguinal canal contains the spermatic cord and ilioinguinal nerve in males, and the round ligament of the uterus and ilioinguinal nerve in females.

Boundaries and Contents of Inguinal Canal

The boundaries of the inguinal canal include the roof (transversalis fascia, internal oblique, and transversus abdominis), floor (inguinal ligament, lacunar ligament), anteriorly (aponeurosis of the external oblique muscle), and posteriorly (transversalis fascia).
The contents of the spermatic cord include arteries (testicular, cremasteric, and ductus deferens), fascia (external spermatic, cremasteric, and internal spermatic), and nerves (genital branch of the genitofemoral nerve, sympathetic fibers, and ilioinguinal nerve).

Clinical Relations of Inguinal Canal

Inguinal hernias can be divided into two main categories: indirect inguinal hernia (peritoneal sac enters the inguinal canal through the deep inguinal ring) and direct inguinal hernia (peritoneal sac enters the inguinal canal through the posterior wall).
Both types of hernias can present as lumps in the scrotum or labia majora, and large herniations can occur through both the deep and superficial rings at the same time (Pantaloon hernias).
Incarcerated hernias can become strangulated hernias, which contain non-viable bowel and can become necrotic, infected, and perforate if not treated.

Peritoneum

The peritoneum is a double layer of peritoneal tissue that lines the abdominal cavity and covers the abdominal organs.
The lesser sac communicates with the greater sac via the epiploic foramen of Winslow, located posterior to the free edge of the lesser omentum.
The greater sac is divided into the supracolic and infracolic compartments by the transverse mesocolon.
The supracolic compartment contains the liver, stomach, and spleen, while the infracolic compartment is divided by the root of the mesentery of the small intestine into the right and left infracolic spaces.
The mesentery is a fold in the peritoneum that holds the organs in place from the back wall of the abdomen, and the omenta are two layers of peritoneum that have fused and extend from the stomach and proximal duodenum to neighboring organs.

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Description

Learn about the anterolateral abdominal wall, its topographical areas, and the four quadrants used to describe the location of abdominal organs and associated pain.