Cervical Fascia

• Superficial cervical fascia:
  • Primarily includes the:
    • Platysma and
    • Subcutaneous fat and vessels:
      • However:
        • As with other fascia in the body:
          • The use of the terminology of the superficial cervical fascia has declined in favor of:
            • Subcutaneous tissue:
              • Thus, an unspecified reference to cervical fascia:
                • Mainly refers to the deep cervical fascia
• The deep cervical fascia:
  • Consists of three separate but related fascial layers:
    • That encircle structures in the neck and
    • Allow anatomic compartmentalisation into:
      • The deep spaces of the head and neck
    • Each layer contributes:
      • To the carotid sheath
  • Layers of the deep cervical fascia:
    • Superficial layer of the deep cervical fascia
    • Middle layer of the deep cervical fascia
    • Deep layer of the deep cervical fascia
• The superficial layer of the deep cervical fascia:
  • Also known as:
    • The investing layer / fascia
  • 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
• The middle layer of the deep cervical fascia:
  • Is the one of the three layers of the deep cervical fascia:
    • It most closely surrounds:
      • The visceral organs
  • This layer consists:
    • Anteriorly of the:
      • Strap muscle fascia:
        • Comprised of the:
          • Sterno-omohyoid layer and
          • Sternothyroid layer
          • Thyrohyoid layer
    • Posteriorly:
      • Visceral fascia:
        • Also commonly known as the:
          • Pharyngobasilar and
          • Buccopharyngeal fascia
            • Particularly in the suprahyoid neck, or, less commonly:
              • Pharyngomucosal fascia
        • The alternative term:
          • Pretracheal fascia:
            • May refer to either:
              • The visceral fascia or
              • The sternothyroid-thyrohyoid layer of strap muscle fascia:
                • Which lies anterior to the trachea
  • Gross Anatomy – attachments:
    • Superiorly:
      • Skull base
    • Anteriorly:
      • Hyoid bone
      • Thyroid cartilage
      • Manubrium
    • Inferiorly:
      • Fibrous pericardium
      • Adventitia of the aortic arch
  • Contents:
    • Infrahyoid (strap) muscles:
      • Sternohyoid
      • Omohyoid
      • Sternothyroid
      • Thyrohyoid
    • Visceral space and pharyngeal mucosal space:
      • Buccinator muscle
      • Pharynx and pharyngeal constrictor muscles:
        • Superior pharyngeal constrictor muscle
        • Middle pharyngeal constrictor muscle, and
        • Inferior pharyngeal constrictor muscle
      • Cervical esophagus
      • Thyroid gland* and parathyroid glands
      • Trachea*
      • Larynx*
      • Visceral lymph nodes
      • Recurrent laryngeal nerve
        • *Some sources consider these structures to have their own fascia not derived from the middle layer of the deep cervical fascia:
          • But they are nevertheless considered part of the visceral space
  • In addition:
    • All layers of the deep cervical fascia:
      • Contribute to the carotid sheath:
        • However:
          • In the suprahyoid neck:
            • Above the carotid bifurcation:
              • The contribution of the middle layer is inconsistent
• The deep layer of the deep cervical fascia:
  • Is one of the three layers of the deep cervical fascia:
    • It encases the:
      • Paravertebral muscles and
      • Forms the perivertebral space
    • It consists of the:
      • Perivertebral fascia:
        • The anterior part of which is called:
          • The prevertebral fascia and
          • The alar fascia
  • Gross Anatomy – attachments:
  • Medially:
    • Ligamentum nuchae
    • Cervical vertebral spinous processes and transverse processes
  • Laterally:
    • Carotid sheath
    • First rib:
      • From a portion of the layer called:
        • Sibson fascia
    • Axillary sheath
  • Superiorly
    • The skull base
  • Inferiorly
    • Coccyx:
      • For the prevertebral fascia)
    • Endothoracic fascia:
      • For the alar fascia
  • On each side:
    • A flap attaches to the transverse processes of the cervical vertebrae and:
      • Divides the peri-vertebral spaces into:
        • A pre-vertebral compartment:
          • Anteriorly and
        • A para-spinal compartment:
          • Posteriorly
  • Anteromedial to the scalene muscles:
    • The deep layer splits into two leaves:
      • The ventral leaf being:
        • The alar fascia, and
      • The dorsal leaf being:
        • The prevertebral fascia:
          • With the prevertebral space:
            • Space between the prevertebral fascia and the spine
        • The space between the alar fascia and the prevertebral fascia:
          • Is the danger space
        • The space between the alar fascia and the posterior aspect of the middle layer of the deep cervical fascia:
          • Is the retropharyngeal space
  • Contents:
    • Danger space:
      • Space between prevertebral and alar fascia
    • Prevertebral space:
      • Space between the prevertebral fascia and the spine:
        • Anterior component:
          • Of the perivertebral space
    • Longus colli and capitis muscles
    • Rectus capitis anterior and lateralis muscles
    • Scalenus anterior, medius, and posterior muscles
    • Sheath for subclavian artery and vein, brachial plexus
    • Vertebral column
    • Spinal cord and associated thecal sac, nerve roots, and vessels
    • Vertebrae and associated discs and ligaments
    • Paraspinal / paravertebral space:
      • Posterior component:
        • Of the perivertebral space
    • Levator scapulae
    • Deep cervical back muscles
    • Pierced by the four cutaneous branches of the cervical plexus:
      • Greater auricular nerve
      • Lesser occipital nerve
      • Transverse cervical nerve
      • Supraclavicular nerve
  • In addition:
    • All layers of the deep cervical fascia:
      • Contribute to the carotid sheath

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