1.Neck

• Cervical fascia


  Layers of fascia in the neck
• Superficial layer of deep cervical fascia

  • Investing/enveloping layer that encircles the deeper parts of the neck
  • Splits to enclose the Trapezius and Sternocleidomastoid muscles
  • Encloses the Submandibular and Parotid glands
• Suprasternal space of Burns

  Space between the anterior and posterior parts of the superficial layer of deep cervical fascia that attach to the borders of the suprasternal notch
• Pretracheal layer


  • Thin layer attached superiorly to the thyroid and cricoid cartilages and inferiorly to the pericardium
  • Surrounds the Larynx and Trachea, encloses the Thyroid and Parathyroid glands
  • Forms a false capsule of the Thyroid gland
• Prevertebral layer


  • Thick layer that passes like a septum across the neck behind the Pharynx and Esophagus and in front of the Prevertebral muscles and the vertebral column
  • Forms the fascial floor of the posterior triangle
  • Extends laterally over the First rib into the Axilla to form the Axillary Sheath
• Carotid sheath


  • Local condensation of the Prevertebral, Pretracheal and Investing layers of the deep cervical fascia
  • Contains the Internal Jugular Vein laterally, the Common and Internal Carotid artery medially, and the Vagus nerve posteriorly
• Organisms originating in the mouth, teeth, pharynx and esophagus


  Can spread among the fascial planes and spaces in the neck
• Retropharyngeal space


  Potential space bounded by deep cervical fascia, lies between vertebral and visceral compartments and contains loose connective tissue
• Most cases of Ludwig's angina are derived from dental infections, especially the 2nd and 3rd molars
• Platysma


  Broad, thin sheet of muscle in the subcutaneous tissue of the neck, muscle of facial expression innervated by the cervical branch of the facial nerve
• Torticollis/Wryneck


  Contraction or shortening of the Sternocleidomastoid muscle, leading to twisting of the neck with the chin pointing upward and to the opposite side
• Hyoid bone


  1. shaped bone that does not articulate with another bone, serves as a moveable base for the tongue, located at the level of C3
• Suprahyoid muscles


  • Digastric (anterior and posterior)
  • Mylohyoid
  • Stylohyoid
  • Geniohyoid
• Infrahyoid muscles


  • Omohyoid (superior and inferior)
  • Sternohyoid
  • Sternothyroid
  • Thyrohyoid
• Suprahyoid muscles


  • Elevate the hyoid bone
• Infrahyoid muscles


  • Depress the hyoid bone and larynx
• Hyoid


  Serves as a moveable base for the tongue, located at the level of C3
• Suprahyoid muscles


  • Digastric (anterior and posterior)
  • Mylohyoid
  • Stylohyoid
  • Geniohyoid
• Infrahyoid muscles


  • Omohyoid (superior and inferior)
  • Sternohyoid
  • Sternothyroid
  • Thyrohyoid
• Suprahyoid muscles


  Elevate the hyoid bone
• Infrahyoid muscles


  Depress the hyoid bone, except sternothyroid which depresses the larynx
• The triangle of the neck bounded by the posterior belly of Digastric muscle, the superior belly of Omohyoid muscle and the anterior border of the Sternocleidomastoid muscle is the Carotid triangle
• Mylohyoid muscle


  Separates the submandibular and sublingual space
• The contents of the upper portion of the carotid sheath are crossed obliquely and anteriorly by the anterior belly of digastric
• The triangle involved when an 18 year old male was stabbed in the neck in front of the right sternocleidomastoid and superior omohyoid muscles and below the hyoid bone is the Carotid triangle
• Boundaries of the Occipital triangle

  • Apex contains portion of occipital bone
  • Occipital artery is found in superior part
  • Accessory nerve crosses the triangle
• Accessory nerve lesions


  Weakness of the Trapezius muscle, difficulty in elevating the scapula/shrugging the shoulder, difficulty in laterally rotating the scapula during abduction of the arm
• Contents of the Supraclavicular triangle

  • External jugular vein
  • Subclavian artery
• Contents of the Posterior triangle

  • Nerves: Brachial plexus trunks, Cervical plexus cutaneous branches, Spinal accessory nerve
  • Arteries: Subclavian, Suprascapular, Transverse cervical, Occipital
  • Veins: Subclavian, External jugular
  • Muscle: Inferior belly of omohyoid
• Thyroid gland


  Right and left lobes connected by a narrow isthmus, pear-shaped, surrounded by pretracheal layer of deep fascia, 20 grams, often has a pyramidal lobe projecting upward from the isthmus, frequently connected to the hyoid bone by a fibrous or muscular band (levator glandulae thyroidea)
• The likely cause of significant bleeding below the isthmus of the thyroid gland during thyroid surgery is the Thyroidea Ima artery
• When performing a low tracheotomy below the isthmus of the thyroid, the Inferior thyroid artery may be encountered
• The key vertebral levels are: C3 - hyoid bone, C4-C5 - thyroid cartilage, C6 - cricoid cartilage
• The thyroid gland develops from a median endodermal thickening in the floor of the primordial pharynx, forming a thyroid diverticulum that descends in the neck, connected to the tongue by a thyroglossal duct
• Thyroglossal duct cyst


  Painless, progressively enlarging movable mass, asymptomatic unless becomes infected, moves up with swallowing or tongue protrusion
• Cancer cells in thyroid malignancy will first metastasize to the cervical lymph node level VI (anterior compartment)
• Cervical lymph node levels

  • I - Submental and Submandibular
  • II - Upper Jugular
  • III - Middle Jugular
  • IV - Lower Jugular
  • V - Posterior triangle
  • VI - Anterior compartment
  • VII - Paratracheal
• Anterior Triangle


  Region of the neck bounded by the sternocleidomastoid muscle, the superior belly of the omohyoid muscle, and the midline of the neck
• Structures that drain into the Deep Cervical Nodes

  • Submental
  • Submandibular
  • Occipital
  • Anterior Cervical
  • Superficial cervical
• Superior Deep Cervical Lymph Nodes

  Lie along the Internal Jugular Vein in the Carotid Triangle of the neck