What Is Superficial Fascia?

The superficial fascia in the anterior and lateral regions of the chest is continuous with the superficial fascia in the neck, abdomen, and upper limbs, and contains fat, superficial blood vessels, lymphatic vessels, cutaneous nerves, and breasts. The thickness varies greatly from individual to individual, with the front of the sternum thinner and the rest thicker.

Superficial fascia

Superficial fascia

From an anatomical perspective, the superficial fascia is located between the dermis and deep fascia (in areas without deep fascia, such as the central part of the face, etc., the superficial fascia can also be located between the dermis and the periosteum) A layer of fatty membrane structure. -Generally it consists of fat and connective tissue fibers. Because its composition often contains more fat components. So sometimes superficial fascia is also called subcutaneous fat. The fat component is more distributed in the superficial fascia. In addition to forming a space between the fat components to fix fat and connect the dermis to the deep fascia, it often forms a layer in the deep layer of the superficial fascia. Thin and thick film structure. Therefore, the superficial fascia can be further divided into a shallow lipid layer and a deep film layer. But in some literatures, you can see "from the superficial and deep epidermis, dermis, fat, superficial fascia ..." and other descriptions. This description separates the fat component from the superficial fascia and changes the original concept of superficial fascia, which is obviously not familiar with the anatomy of superficial fascia.

The cutaneous nerves in the anterior and lateral regions of the cutaneous nerve come from the cervical plexus and the superior costal nerve branches. Three to four supraclavicular nerves are sent from the cervical plexus through the neck down to the front of the clavicle and are distributed in the upper part of the anterior chest and shoulder skin. Anterior and lateral cutaneous branches of intercostal nerves: Except for the supraclavicular nerve distribution area, the skin of the anterior and lateral regions of the intercostal nerve is distributed by the anterior and lateral cutaneous branches of the intercostal nerve. The intercostal nerves issue lateral cutaneous branches near the anterior axillary line, which are distributed on the skin outside the thoracic region and the lateral side of the anterior thoracic region. The intercostal nerve's cutaneous branch distribution is obviously segmental, arranged in nerve order from top to bottom, in the shape of a circular strip. The 2nd intercostal nerve is distributed on the skin of the sternal angle, and the lateral cutaneous branches are still distributed to the medial arm; the 4th intercostal nerve to the papillary plane; the 6th intercostal nerve to the sword-thoracic junction plane; the 8th intercostal nerve to the rib Bow plane. The distribution of the cutaneous nerve can be used to determine the level of anesthesia and to diagnose segments of spinal cord injury. The distribution of adjacent cutaneous nerves overlap each other and collectively manage the skin sensation in a banded zone. For example, the skin on the fourth intercostal plane receives the cutaneous branches from the third and fifth intercostal nerves in addition to the fourth intercostal nerve. Therefore, one intercostal nerve is damaged, and the sensory disturbance in the distribution area is not obvious. This loss of joint management of the zonal zone occurs when two adjacent costal nerves are damaged.

Superficial blood vessels are mainly supplied by branches such as the internal thoracic artery, posterior intercostal artery, and axillary artery. The veins flow into the thoracic and abdominal wall veins and the accompanying veins of the aforementioned arteries. Perforating branch of internal thoracic artery: It is small and penetrates about 1cm from the lateral edge of the sternum and is distributed to the medial part of the anterior thorax. Women's 2nd to 4th perforators are larger and branch to

Consists of fat and loose connective tissue. The superficial fascia assisted by the abdominal wall is divided into two layers: the superficial layer, which contains adipose tissue, also called the fat layer, and is continuous with the superficial fascia of the thigh; the deep layer, Scarpa fascia, is a membrane-like layer rich in elastic fibers , At the midline on the white line, down to about a transverse finger below the inguinal ligament, attached to the deep femoral fascia; but between the left and right pubic nodules across the pubic symphysis and continue down to the scrotum, and the shallow perineal tendon The membrane is connected. The superficial fascia contains superficial abdominal wall arteries, veins, superficial lymphatic vessels, and cutaneous nerves. The superficial artery in the upper part of the anterior abdominal wall is small and is a branch of the posterior intercostal artery. There are two large superficial arteries in the lower half of the anterior abdominal wall: the superficial abdominal wall arteries start from the femoral artery, cross the middle and inner 1/3 junction of the inguinal ligament, and go to the umbilicus with an outer diameter of about 1mm; outside the superficial abdominal artery There is still a superficial circumflex artery that runs from the femoral artery to the iliac crest, and its outer diameter is about 1.2 mm. Because the superficial artery of the anterior abdominal wall runs between the superficial and deep layers of the superficial fascia and accompanies the vein of the same name, it is often cut at the lower part of the abdomen to replace the pedicle or free flap. The superficial veins of the ventral anterior lateral wall are richer, and they kiss each other to form a net, especially in the umbilical region.