SUPERFICIAL & DEEP FASCIA

Yapa WijeratneFaculty of Medicine

University of Peradeniya

Fascia: masses of connective tissue large enough to be visible to the unaided eye.

Superficial fascia The skin is connected to the underlying bones or deep

fascia by a layer of loose areolar connective tissue. This layer, usually referred to as superficial fascia, is of

variable 1. Thickness 2. Fat content3. Flat sheets of muscles- in some regions.

The quantity and distribution of subcutaneous fat differs o in the sexes-more in females. o with climate (rather than race)-more in colder geographical

regions.

Flat sheets of muscles are also present in some regions. These include

Skeletal muscles Platysma Palmaris brevis

Smooth muscles Subareolar muscle of the nipple Dartos Corrugator cutis ani

The superficial fascia is most distinct on the lower abdominal wall where it differentiates into two layers.

Superficial fascia is Well differentiated in

1. limbs 2. perineum

Thin1. Dorsal aspects of the hands and feet, 2. the sides of the neck and face, 3. around the anus4. over the penis and scrotum

Almost absent external ears.

Strong connective tissue bands traverse the superficial fascia binding the skin to the underlying aponeurosis of the scalp, palm and sole.

Typical superficial fascia is lacking in the palms and soles, where numerous strong connective tissue collagenous bands tether the dermis of the skin to underlying structures.

Also atypical is the skin of the scalp, where dense dermal connective tissue and the epicranial aponeurosis are bound together as a layer that ‘rides’ on loose connective tissue overlying the periosteum of the skull.

Deep fascia The limbs and body wall are wrapped in a membrane

of fibrous tissue, the deep fascia. It varies widely in thickness. Very well developed:

iliotibial tract of the fascia lata So thin/Scarcely demonstrable (usually considered to

be absent): Over the rectus sheath External oblique aponeurosis of the abdominal wall

Entirely absent: Face, Ischioanal fossa

Where deep fascia passes directly over bone it is always anchored firmly to the periosteum.

In the neck, as well as the investing layer of deep fascia, there are other deeper fascial layers enclosing neurovascular structures, glands and muscles.

Intermuscular septa are laminae of deep fascia which extend between muscle groups and frequently become continuous with the periosteum of bones.

Transverse thickenings of deep fascia over tendons, attached at their margins to bones, form retinaculae at the wrists and ankles and fibrous sheaths on the fingers and toes.

Deep fascia is very sensitive. Its nerve supply, and that of subcutaneous

periosteum, is that of the overlying skin. The nerves to muscles supply the

intermuscular septa and deep periosteum.