Superficial & deep fascia

1. Yapa Wijeratne
Faculty of Medicine
University of Peradeniya

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

3.  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 content
3. 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.

4.  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

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

8.  Well differentiated in
1. limbs
2. perineum
 Thin
1. Dorsal aspects of the hands and feet,
2. the sides of the neck and face,
3. around the anus
4. over the penis and scrotum
 Almost absent
 external ears.

9.  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.

10.  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

11.  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.

12.  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.