Learning Objective
By the end of this article, learners will be able to describe the layers of cervical fascia, their attachments, anatomical relationships, and clinical relevance, including fascial spaces and the carotid sheath.
Fascial Layers of the Neck
Fascia is internal connective tissue forming bands or sheets that surround and support muscles, vessels, and nerves. In the neck, fascial layers not only provide support but also compartmentalise structures, influencing the spread of infection or disease.
There are two major types in the neck:
- Superficial cervical fascia
- Deep cervical fascia
Superficial Cervical Fascia
- Located between the dermis and deep cervical fascia.
- Contains:
- Neurovascular supply to the skin
- Superficial veins (e.g., external jugular vein)
- Superficial lymph nodes
- Fat
- Platysma muscle
Platysma
- Broad superficial muscle lying anteriorly.
- Two heads originating from the fascia of pectoralis major and deltoid; fibers cross the clavicle and fuse in midline with facial muscles.
- Superior insertion: inferior border of the mandible.
- Innervation: cervical branch of the facial nerve.
Activity
Deep Cervical Fascia
- Lies deep to the superficial fascia and platysma.
- Organized in layers, acting like a “shirt collar,” supporting neck structures.
Layers (superficial → deep):
Investing Layer
-
- Most superficial deep fascia.
- Surrounds all neck structures; splits around the trapezius and sternocleidomastoid.
- Attachments:
- Superior: external occipital protuberance, superior nuchal line
- Anterior: hyoid bone
- Inferior: scapular spine/acromion, clavicle, manubrium
- Posterior: nuchal ligament
Pretracheal Layer
- Located anteriorly; spans the hyoid → thorax (fusing with the pericardium).
- Encloses trachea, oesophagus, thyroid gland, and infrahyoid muscles.
- Subdivisions:
- Muscular part: infrahyoid muscles
- Visceral part: thyroid, trachea, oesophagus
- Posterior aspect: contribution from buccopharyngeal fascia
Prevertebral Layer
- Surrounds the vertebral column and associated muscles (scalene, prevertebral, deep back muscles).
- Attachments:
- Superior: base of skull
- Anterior: vertebral bodies & transverse processes
- Posterior: nuchal ligament
- Inferior: the endothoracic fascia of the ribcage
- Forms the floor of the posterior triangle; surrounds the brachial plexus and the subclavian artery → axillary sheath
Carotid Sheath
- Paired fascia enclosing the neurovascular bundle of the neck:
- Common carotid artery
- Internal jugular vein
- Vagus nerve
- Cervical lymph nodes
- Formed from investing, pretracheal, and prevertebral fascia
- Extends skull base → thoracic mediastinum
- Clinical importance: a pathway for infection spread
Clinical Relevance – Fascial Spaces
-
Fascia compartmentalises the neck; infection spread is guided by fascial planes:
Retropharyngeal space
- Between the buccopharyngeal fascia and the prevertebral fascia
- Base of skull → posterior mediastinum
Visceral space
- Enclosed by visceral pretracheal fascia
- Hyoid → superior mediastinum
- Superficial infections may be contained by fascia (e.g., skin abscess)
- Deep infections can track along these spaces to the mediastinum, leading to serious complications
