Middle layer of the deep cervical fascia

The middle layer of the deep cervical fascia is the one of the three layers of the deep cervical fascia that most closely surrounds the visceral organs. This layer consists anteriorly of the strap muscle fascia (comprised of the sterno-omohyoid and sternothyroid-thyrohyoid layers) and posteriorly of the 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, middle, and inferior)
  • 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 .