The Neck
Lecture Objectives
• Define the boundaries of the neck.• Describe the fasciae of the neck.• Summarize the main arteries, veins, nerves and lymph nodes of the neck.
• List the muscles of the neck.• Describe the neck triangles.• Describe the key muscles creating the triangles, mainly, sternomastoid, omohyoid and digastric.
• Study the boundaries and content of each triangle.
Boundaries of the Neck
• Superior margin• Inferior margin
• Root of the neck
Cervical Vertebral Muscles• Suboccipital and deep neck musclesMainly extends head and neck• Rectus capitis posterior major m.• Rectus capitis posterior minor m.• Oblique capitis inferior m.• Oblique capitis superior m.
Cervical Prevertebral Muscles
• Anterior vertebral musclesMainly flexes head and neck
• Longus coli m.• Longus capitis m.• Rectus capitis anterior m.• Anterior scalene m.
• Lateral vertebral musclesMainly laterally flex head and neck
• Rectus capitis lateralis m. • Splenius capitis m.• Levator scapulae m.• Middle scalene m.• Posterior scalene m.
Cervical fascia
• Superficial fascia• Deep fascia:
• Investing layer• Pretracheal layer• Prevertebral layer• Carotid sheath
Cervical Fascia• Superficial fascia
• platysma
• Deep fascia:• Investing layer
• Trapezius & SCM• Pretracheal layer
• Visceral part ‐ Thyroid & parathyroid• Buccopharyngeal fascia ‐
pharynx• Muscular part ‐ Infrahyoid mm.
Cervical Fascia
• Deep fascia (continue…)• Prevertebral layer
• Posterior to pharynx & esophagus
• Vertebral mm.• Continue as axillary sheath
• Carotid sheath• Thickening of the other layers• Common & internal carotid aa.
• Intrnal jugular v.• Vagus n.• Deep cervical lymph nodes
Cervical Fascia: Extensions
• Alar fascia• Division from prevertebral fascia• From skull to T2 (merge with buccopharyngeal fascia)
• Buccopharyngeal fascia• Superior & posterior continuation of the pretracheal fascia
Cervical Fascia: Spaces
• Retropharyngeal space• Between buccopharyngeal fascia and prevertebral fascia
• Spread of infections(Real) Retropharyngeal space
• Between the alar fascia and buccopharyngeal fascia
• Allow movement of pharynx, larynx, and trachea during swallowing
• Continuous with superior mediastinum to T2
Danger space• Between the alar fascia and the prevertebral fascia
• Continuous with mediastinum
Neck Triangles: Boundaries
• Anterior triangleAnterior to SCM• Carotid triangle• Digastric triangle• Submental triangle• Muscular triangle
• Posterior trianglePosterior to SCMAnterior to trapezius• Occipital triangle• Supraclavicular triangle
Neck Triangles: Content
Sensory Innervations of the Neck
Root of the Neck
Arteries of the Head and Neck
Veins of the Head and Neck
Principal groups of lymph nodesLymph drainage of Head and neck
• Regional lymph nodes• Occipital• Retroauricular• Parotid• Buccal• Submandibular• Submental• Anterior cervical• Laryngeal• Tracheal• Superficial cervical
• Deep cervical• Jugular trunk
Occipital Triangle
• Above the inferior belly of omohyoid m.
• Spinal accessory nerve (XI)• Junction of the superior & middle thirds of the posterior border of SCM → junction between middle & lower thirds of the anterior border of trapezius
• Injury
Anterior Triangle
• Carotid triangle• Carotid sheath
• Between sternocalvicular joint and the mid point between mastoid and angle of mandible
• Hypoglossal nerve• Cervical sympathetic trunk
• Submandibular (digastric) triangle • Submandibular gland• Submandibular lymph nodes
Surface Anatomy of the Neck
• Hyoid bone – C3• Posterior to the mandible
• Laryngeal prominence (Adma’s apple)‐ tip (C4)• Vocal cords – at the middle
• Cricoid cartilage – C6 • Cricothyroid ligament
• Cricothyrotomy
• First tracheal cartilage• Tracheostomy
• Thyroid gland • Isthmus – 2nd – 4th tracheal rings
Tracheostomy