Muscle groups of the neck

  • Post-vertebral muscles
  • Anterior vertebral muscles
  • Lateral vertebral muscles
  • Anterior neck muscles
  • Superficial neck muscles

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*Refer medical museum models

Anterior vertebral muscles

  • Muscles
    • Rectus capitis anterior
    • Longus capitis
    • Longus colli
  • Attachment
    • base of the skull & bodies
    • transverse processes of cervical
    • upper 4 thoracic vertebrae
  • Nerve supply
    • C1 – C6
  • Action
    • flex head & neck

Lateral vertebral muscles

  • Muscles
    • Rectus capitis lateralis
    • Levator scapulae
    • Anterior scalene
    • Middle scalene
    • Posterior scalene
  • Attachments
    • vary
  • Nerve supply
    • C1 – C8
  • Actions
    • vary

Anterior neck muscles

  • Above hyoid bone (suprahyoid)
    1. Mylohyoid
      • Origin
        • mylohyoid line of mandible
      • Nerve supply
        • Mandibular division of 5th CN
      • Action
        • Elevates floor of mouth (Swallowing)
    2. Digastric (ant & post bellies)
      • Origin
        • digastic fossa (anterior belly)
        • mastoid process (posterior belly)
      • Insertion
        • intermediate tendon to greater horn & body
      • Nerve supply
        • Anterior belly: mandibular division of 5th CN
        • Posterior belly: facial nerve
      • Actions
        • depresses the mandible (open mouth)
        • elevates the hyoid bone on swallowing
  • Below hyoid bone (infrahyoid)
    • Strap muscles
      1. Sternohyoid
        • Origin
          • manubrium
        • Insertion
          • body of hyoid
        • Nerve supply
          • ansa cervicalis (C1-C3)
        • Action
          • depresses the hyoid after elevation during swallowing
      2. Omohyoid
        • Origin
          • Superior border of scapula
        • Insertion
          • body of hyoid
        • Nerve supply
          • Ansa cervicalis (C1-C3)
        • Action
          • same as above
      3. Sternothyroid
        • Origin
          • manubrium
        • Insertion
          • obliqueline of thyroid cartilage
        • Nerve supply
          • Ansa cervicalis (C2-C3)
        • Action
          • same as above
      4. Thyrohyoid
        • Origin
          • oblique line of thyroid cartilage
        • Insertion
          • body of hyoid
        • Nerve supply
          • Ansa cervicalis (C1 – via hypoglossal nerve)
        • Action
          • same as above
          • elevates the larynx*

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Superficial neck muscles

  1. Sternocleidomastoid muscle
    • Key muscle of the neck
    • Anterior to it
      • anterior triangle
    • Posterior to it
      • posterior triangle
    • Origins of 2 heads
      • sternal head
        • manubrium sterni
      • clavicular head
        • superior surface of medial end of clavicle
    • Insertion
      • mastoid process
      • lateral half of superior nuchal line
    • Nerve supply
      • spinal accessory nerve (11th CN)
    • Actions
      • Unilateral contraction
        • tilts the head to the same side & rotate
          • face turned upwards to opposite side
      • Bilateral contraction
        • extends neck at atlanto-occipital joint
        • flexes the cervical spine anteriorly
          • looking at the strs
  2. Trapezius
    • Large flat triangular muscle
    • Extends covering the cervical region & thorax
    • Origin
      • Medial 3rd of superior nuchal line
      • External occipital protuberance
      • Nuchal ligament
      • Spines of C7 downwards
    • Insertion
      • spine of the scapula
      • Acromion
      • Lateral 3rd of clavicle
    • Nerve supply
      • spinal accessory nerve (same as SCM)
    • Actions
      • Elevates scapula (superior fibres)
      • Retracts scapula (middle fibres)
      • Depresses scapula (inferior fibres)
      • Rotates scapula (superior & inferior fibres)
        • butterfly style of swimming

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Muscular triangles of the neck

  • Vertebral triangle
    • Gap between anterior scalene & longus colli
    • Bounderies
      • apex: C6 anterior tubercle
      • base: subclavian artery
  • Posterior triangle
    • Occipital & Subclavian triangle
    • Contents*
      • Occipital artery
      • Accessory nerve
      • External jugular vein
      • Subclavian artery
  • Anterior triangle
    1. Submental triangle
      • Borders: digastric (anterior), hyoid bone, mandible
    2. Digastric triangle
      • Borders: digastric (anterior), mandible
    3. Carotid triangle
      • Borders: digastric (posterior), superior belly of omohyoid
      • Contents*
        • common carotid artery
        • external carotid artery
        • internal jugular vein
        • vagus nerve
    4. Muscular triangle
      • Borders: Hyoid, Sternohyoid (2)
      • Contents*
        • larynx
        • t
          rachea
        • thyroid gland

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