Posterior triangle of the neck which divides the space into two triangles: A) Nerves and plexuses: B) Vessels: C) Lymph nodes: D) Muscles: The accessory nerve (CN XI) is particularly vulnerable to damage during lymph node biopsy. Damage results in an inability to shrug the shoulders or raise the arm above the head, particularly due to compromised trapezius muscle innervation. The Internal jugular vein's superficial location within the posterior triangle also makes it vulnerable to injury. Posterior triangle of the neck The posterior triangle (or lateral cervical region) is a region of the neck. It has the following boundaries: Apex: Union of the sternocleidomastoid and
Fascial spaces of the head and neck In the head and neck, potential spaces are primarily defined by the complex attachment of muscles, especially mylohyoid, buccinator, masseter, medial pterygoid, superior constrictor and orbicularis oris. Infections involving fascial spaces of the head and neck may give varying signs and symptoms depending upon the spaces involved. Trismus (difficulty opening the mouth) is a sign that the muscles of mastication (the muscles that move the jaw) are involved. Dysphagia (difficulty swallowing) and dyspnoea (difficulty breathing) may be a sign that the airway is being compressed by the swelling. Different classifications are used. One method distinguishes four anatomic groups: Since the