Anatomy - Cesarean section

The skin consists of two main layers:

1. Epidermis: The outermost layer, composed of keratinized squamous epithelium. It provides protection against physical and chemical influences.
2. Dermis: Located beneath the epidermis and contains blood vessels, nerves, sebaceous and sweat glands, as well as hair follicles. This layer is responsible for the elasticity and strength of the skin.

Subcutaneous fat tissue: This layer beneath the dermis serves as a buffer zone and energy reserve. It contains:

1. Adipocytes: Fat cells that dominate the subcutaneous layer.
2. Blood vessels and nerves: They run through this layer and can vary individually. Superficial veins and smaller arteries are located here.

Rectus Sheath:

The rectus sheath is a firm, tendinous structure that envelops the anterior and posterior abdominal muscles. It is formed from the aponeuroses of the abdominal musculature:

External oblique muscle: The aponeurosis of this muscle forms a significant part of the anterior rectus sheath.

Internal oblique muscle: This aponeurosis splits above the arcuate line into an anterior and posterior portion, forming both the anterior and posterior layers of the rectus sheath.

Transversus abdominis muscle: Its aponeurosis reinforces the posterior layer of the rectus sheath above the arcuate line. Below this line, all aponeuroses contribute to the anterior layer.

The rectus sheath is connected at the linea alba, a vertical tendinous structure extending from the xiphoid process of the sternum to the pubic symphysis.

Important anatomical structures run within the rectus sheath, such as the superior epigastric artery and vein (above the arcuate line) and the inferior epigastric artery and vein (below the arcuate line). These blood vessels supply the abdominal wall and must be preserved during surgical procedures.

The rectus sheath provides stability and protection for the underlying rectus abdominis muscle as well as the intra-abdominal contents and is essential for the integrity of the abdominal wall.

Along the linea alba, a tendinous connection between the rectus sheaths, a surgical approach can be created. This region is relatively avascular, minimizing bleeding.

M. rectus abdominis:

Origin: The muscle originates from the pubic symphysis and the pubic crest.

Insertion: Inserts at the costal cartilage of the 5th to 7th ribs and the xiphoid process.

Function: Primarily responsible for trunk flexion; increases intra-abdominal pressure during abdominal press and stabilizes the upper body.

Special feature: The muscle is segmented by the tendinous intersections, creating its characteristic appearance. During surgical procedures, it is typically not incised but carefully retracted.

M. pyramidalis:

Origin: Originates at the anterior part of the pubic bone and the pubic symphysis.

Insertion: Inserts into the linea alba, which it tenses.

Function: Stabilizes the central abdominal wall structure and provides tension in the linea alba.

Variability: The muscle may be absent, which does not cause functional limitations.

Parietal Peritoneum:

This layer lines the inside of the abdominal wall and forms the outer boundary of the abdominal cavity.

It is a smooth, serous membrane that provides mechanical protection and facilitates the movement of the underlying organs.

During a cesarean section, the parietal peritoneum is incised to gain access to the abdominal cavity.

Visceral Peritoneum:

It covers the organs in the abdominal cavity, including the uterus (Corpus uteri).

In the area of the lower uterine segment, it lies particularly close as it envelops the anterior uterine wall.

Before a hysterotomy, this peritoneum is carefully incised and mobilized.

The bladder is located immediately in front of the lower uterine segment, separated by the vesicouterine peritoneum. This must be carefully detached from the uterus and mobilized downward during the operation to avoid injury.