46. Abdomen. Anterior abdominal wall. Inguinal canal.

Boundaries:

Sup: Inf. margin of costal arches + xyphoid process.

Lateraly: Post. axillary lines

Inf: inguinal canal, iliac crests + pubic symphysis.

Surface Anatomy:

1. Skin and subcutaneous tissue
2. 1.1 Fatty layer (panniculus adiposus) – contains subcutaneous veins
3. 1.2 Fascia of Camper – composed of fine fibrous fibers within subcutaneous fat
4. Fascia of Scarpa (fascia subfascia abdominis)
5. a membranous layer of subcutaneous tissue (stratum membranosum telae subcutaneae) – separates the subcutaneous and deep fatty layer
6. Deep fatty layer – thinner than the superficial fatty layer
7. Superficial abdominal fascia – the fascia of the external oblique
8. External oblique
9. Internal oblique
10. Transversus abdominis
11. Transversalis fascia – part of the parietal abdominal fascia
12. Parietal peritoneum

Superficial fascia

* Campar's fascia— consist of fatts,

• thinner around the linea alba.
• absent around the umbilicus.
• Continues with the superficial fascia of the thigh.

* Scarp's fascia - membranous layer.

• fuses inferiorly with the fascia lata of the thigh.
• In males, it extends onto the dorsum of the penis, forming the funiform ligament.
• In females, it extends into the labia majora & connects to the Colle's fascia.

Blood vessels & Nerves:

• The space between the two components of superficial abdominal fascias contains adipose tissue, through which superficial blood vessels and nerves pass.
• In the lower abdomen, branches of the epigastric and circumflex iliac arteries are close to the midline.
• The branches of the pudendal arteries and veins are distributed around the superficial inguinal ring.
• In the upper abdominal wall, arterial branches are smaller and originate from the intercostal and lumbar arteries.

Venous Anastomoses:

• Subcutaneous veins in the umbilical region anastomose from three venous systems: superior vena cava, inferior vena cava, and portal vein.
• These anastomoses can form a characteristic pattern around the umbilicus called the “caput medusae”.
• The connections (cava-caval and porto-caval) occur between tributaries of major venous systems 1.

Clinical Significance:

1. Hernias:

• The anterolateral abdominal wall is a common site for hernias. These occur when abdominal contents (such as intestines) protrude through weakened areas in the muscle layers.
• Common types include inguinal hernias, femoral hernias, and ventral/incisional hernias.
• Surgical repair is often necessary to prevent complications.

1. Surgical Incisions:

• Surgeons choose specific incisions in this region for various procedures.
• For example, the McBurney incision (right lower quadrant) is commonly used for appendectomy.
• The paramedian incision provides access to the midline structures.