1.1 Fascia & Fascial Spaces of the neck Flashcards
The platysma is a broad thin sheet of muscle lying in the anterolateral aspect of the neck:
• Originates from the fascial coverings of the pectoral and deltoid regions, and ascends anteromedially to the lower border of mandible (blends with muscles of the lower lip)
• _________________ are deep to the platysma
• Helps in depression of the mandible against resistance (muscle of facial expression → conveys tension or stress) and tenses the skin of the inferior face and neck (produces vertical skin ridges and releases pressure on the superficial veins)
• Innervation: ____________________
EJV and the main cervical cutaneous nerves;
cervical branch of the facial nerve (CN VII)
The investing layer of the deep cervical fascia is the most superficial deep fascial layer, and surrounds the entire neck circumferentially:
• Originates from the ligamentum nuchae and spinous processes of the cervical vertebrae
• Attached to the chin, hyoid bone, and manubrium of sternum
• Splits into superficial and deep layers at the “four corners” of the neck to invest the trapezius and SCM (innervated by CN XI)
Attachments
- Superior: _______________ of occipital bone, ______________ of temporal bones, zygomatic arches, angle and entire base of mandible
- Inferior: Manubrium of sternum, clavicles, acromion processes, scapular spines
- Anterior: ______________
- Posterior: Ligamentum nuchae, spinous processes of the cervical vertebrae
- Rule of 2s: encloses 2 glands, 2 spaces, 2 muscles, forms 2 thickenings, roofs 2 triangles
Superior nuchal lines;
mastoid processes;
Hyoid bone
[Investing layer of fascia]
- Trapezius and SCM: Splits into the superficial and deep layers to invest the muscles
• Roofs the anterior and posterior triangles between muscles
- Parotid and submandibular glands: Splits just inferior to its mandibular attachment to enclose the submandibular gland; splits posterior to the mandible to form the fibrous capsule of the parotid gland
• _______________ thickened modification of the posterior capsule of the parotid gland
• _________________: formed by superficial layer (anterior capsule of the parotid gland) → swellings are very painful - Supraclavicular and suprasternal space of Burns: Remains split inferiorly between the ___________________ and just superior to the manubrium, and attaches to the anterior and posterior surfaces of the manubrium:
• Supraclavicular space: EJVs, supraclavicular nerves
• Suprasternal space: inter-clavicular ligament, SCM, jugular venous arch, loose areolar tissue
Stylomandibular ligament:;
Parotidomasseteric fascia;
sternal heads of the SCM
The thin pretracheal layer of the deep cervical fascia is limited to the anterior part of the neck, extending from the hyoid into the thorax (blends with fibrous pericardium):
• Thickens superior to the __________ to form a pulley/trochlea through which the intermediate tendon of the digastric muscle passes to suspend the hyoid
• Wraps around the lateral border of the intermediate tendon of the omohyoid to tether the omohyoid muscle
Layer:
- Muscular: _________________
- Visceral: Thyroid gland (forms false capsule → very thin posteriorly → thyroid swellings grow posteriorly and cause dysphagia), trachea, oesophagus:
• Continuous ____________________ as the buccopharyngeal fascia
• Blends laterally with _____________
• Thickens as the __________________ which attaches the thyroid to the cricoid cartilage (thus thyroid moves with swallowing)
hyoid bone;
Infrahyoid (strap) muscles;
posteriorly and superiorly;
carotid sheaths ;
ligament of Berry
The prevertebral layer of the deep cervical fascia forms a tubular sheath for the vertebral column and its associated muscles, and contains the cervical sympathetic trunks:
• Associated muscles: __________________anteriorly, ___________ laterally (forms floor of the posterior triangle), and the deep cervical muscles posteriorly
Attachments
- Superior: Cranial base
- Inferior
• Peripherally: blends with _______________
(continues into thorax)
• Centrally: fuses with _____________ (about the level of T3) - Anterior: Transverse processes and vertebral bodies of vertebral column
- Posterior: Ligamentum nuchae of vertebral column
- Lateral: Continuous as the axillary fascia/sheath
(contains axillary vessels and brachial plexus) → spinal TB may spread to axilla/posterior triangle
longus colli and longus capitis;
scalenes;
endothoracic fascia ;
anterior longitudinal ligament;
The alar fascia is a fascial layer extending from the cranial base to the level of the C7 vertebra:
• Lies posterior to the larynx, pharynx, and buccopharyngeal fascia
• Attached to the transverse processes of the cervical vertebrae
• Blends with the _______________________ (at the level of T6)
posterior fascia of the oesophagus
The carotid sheath is a tubular fascial sheath which envelopes the vessels of the neck, vagus nerve (CN X), sympathetic nerve fibres, deep cervical lymph nodes and the carotid sinus nerve:
• Formed by all 3 layers of the deep cervical fascia (anteriorly investing layer, posteriorly prevertebral layer, medially pretracheal layer) and extends from the base of the skull to the root of the neck
• Contains the ___________________
common carotid artery and internal carotid artery (medially), internal jugular vein (laterally), and vagus nerves (posteriorly)
The anterior (pretracheal) visceral space lies between the _________________________________
• Extends from the hyoid bone to the superior mediastinum
• Encloses the trachea, thyroid and parathyroid glands, larynx, oesophagus, recurrent laryngeal nerves (in the tracheooesophageal groove), sympathetic nerves
muscular layer of the pretracheal layer and the buccopharyngeal fascia
RETROPHARYNGEAL SPACE
The retropharyngeal space is the largest and most important intra-fascial space in the neck lying between the _______________________:
• Extends from the base of the skull (clivus) to the superior mediastinum
• Permits the movement of the pharynx and oesophagus, larynx and trachea during swallowing
buccopharyngeal fascia and alar fascia
PREVERTEBRAL SPACE
The prevertebral space is a fascial space which lies between the prevertebral fascia and the vertebral column:
• Extends from the skull to the coccyx, enclosing the prevertebral, paravertebral and posterior vertebral muscles
• Pathologies arising from the vertebral column, intervertebral discs, or spinal cord or penetrating injuries may affect the prevertebral space
• Infections may also spread into the ____________________
axilla (due to the continuation of the prevertebral layer as the axillary sheath)
DANGER SPACE
The danger space is a fascial space lying between the _____________________:
• Extends from the skull to posterior mediastinum (can be visualised _______________ → separated from retropharyngeal space), filled with loose connective tissue
• Serves as a potential route for rapid spread of infections towards the posterior mediastinum (offers little resistance to spread)
Retropharyngeal abscesses: pus in the prevertebral space may perforate the __________________ to enter the retropharyngeal space
- Produces a bulge behind the pharynx , which may cause difficulty in swallowing ( and speaking)
- Infection is directed inferiorly towards the superior mediastinum
alar fascia and the prevertebral fascia;
below level of T6;
prevertebral and alar fascia
