Cervical fascia and posterior triangles of neck

Applied Anatomy

..... Nerve point of the neck: is the region around the midpoint of the posterior border of the sternocleidomastoid muscle. Several nerves lie superficially here, deep to the platysma. This point is important because:-


    • Slash wounds of the neck may severe these relatively superficial nerves , resulting in loss of cutaneous sensation in the neck, and posterior part of the scalp.


    • Anaesthetic agent can be injected here.

    Brachial plexus block . Local anaesthetic solution is injected around the brachial plexus, superior to the midpoint of the clavicle. Be careful to locate the subclavian artery by palpation so it is not damaged.

    Subclavian artery, can be pressed in the suprascapular fossa, to control bleeding in the upper limb.

    Block dessection, is sometimes done in this region for the removal of lymph nodes. The accessory and Phrenic nerves, together with the other structures should be saved.

     

    Safe/ danger sides. The accessory nerve may be used to divide the posterior triangle into a carefree area superiorly and a danger area inferiorly, which has major nerves and blood vessels

    Investing Fascia: Forms a tight sheath for the glands especially the parotid, restricting swelling. Iinflammation of this glands causes pain due to high pressure.

     

    Pretracheal Fascia:

  • The thyroid is completely enclosed in pretracheal fascia. The attachments to the larynx and trachea result in movement of the thyroid gland with larynx during swallowing. When a neck swelling moves in this way, it is almost certain to be associated with the thyroid gland.

  • The Spaces around the pretracheal fascia provides for spread of infection. Thus infections from the head and neck can spread infront of the trachea or behind the esaophagus and reach the superior mediastinum .

    Prevertebral Fascia:

    The retropharyngeal space between pharynx and pre-vertebral fascia is clinically important because it frequently becomes infected secondary to upper respiratory tract infrections in childhood. The swelling appears on one side of the posterior pharyngeal wall and may obstruct the airway. In adults such infections are usually secondary to tuberculosis of the cervical vertebral column.

     

     

    External Jugular Vein is relatively superficial therefore:

  • It can be easily lacerated

  • Can be used to draw blood, infuse drugs or catheterize the heart

  • is visible when distended in heart failure

........ It pierces investing fascia therefore, when lacerated

  • Can bleed profusely

  • Predispose to air embolism