Superficial layer of the deep cervical fascia

The superficial layer of the deep cervical fascia, also known as the investing layer, is the one of three layers of the deep cervical fascia that surrounds all of the neck that is deep to the platysma. The layer includes the masticator fascia, submandibular fascia, and sternocleidomastoid-trapezius fascia . The fascia that superficially covers the parotid gland may also be derived from this layer, but this inclusion is controversial .

Gross anatomy

Attachments

• posteriorly
  • ligamentum nuchae 
  • cervical vertebral spinous processes
  • external occipital protuberance
• superiorly
  • mandible
    • the layer thickens to form the extrinsic ligaments of the mandible: sphenomandibular ligament and stylomandibular ligament
  • mastoid process and styloid process
  • central skull base 
  • zygomatic arch
  • superior temporal line or temporal ridge 
• inferiorly
  • manubrium
  • clavicle
  • acromion and spine of the scapula

Contents

The superficial layer of the deep cervical fascia encircles everything in the neck apart from the skin and superficial cervical fascia (subcutaneous tissue). In addition, it splits to enclose the following structures :

• two salivary glands
  • submandibular gland
  • parotid glands
• two spaces
  • masticator space
  • suprasternal space
• two muscles (other than those in the masticator space)
  • sternocleidomastoid muscle
  • trapezius muscle

In addition, all layers of the deep cervical fascia contribute to the carotid sheath.