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
Anterior spinal veins infiltrate back into the ventral median spinal fissure previously mentioned by up to a few centimeters. They are also not only smaller in size but more numerous than the equivalent anterior spinal artery which they lie dorsal to. There are three anterior spinal veins in total. These, along with three posterior spinal veins, are allowed to communicate with one another as they run interconnected throughout the entire length of the spinal cord. This is seen through both sets of veins combining to form a network of anastomoses around the conus medullaris. Together, these two sets of veins also collect blood