Posterior Triangle Flashcards
Investing layer (superficial) fascia
A sleeve binding all the structures in the neck; attached to ligamentum nuchae and spinous process of C7 vertebrae; splits to enclose the trapezius and sternocleidomastoid
Infrahyoid fascia
Covering the supra and infrahyoid muscles; helps reposition the hypopharyngeal complex (larynx, hyoid bone, jaw)
Pretracheal fascia
Viscera surrounded with a layer of fascia including the thyroid and parathyroid glands, trachea, and esophagus
Carotid sheath
Carotid artery, internal jugular vein, and vagus nerve
Prevertebral fascia
Deep cervical fascia covering vertebral musculature
Why are the fascial layers of the neck so important?
The fascia serves to hold things together. It also allows the muscles to slide against and around one another and isolate them, allowing them to move without interference
What is the posterior triangle made up of?
The sternocleidomastoid, the trapezius, and the clavicle
What are the sub-triangles of the posterior triangle?
The occipital triangle and the omoclavicular triangle
Action of the sternocleidomastoid
Unilaterally acts to tilt the head to the same side and rotate the head to the opposite side. Bilaterally acts to extend the head and aid in respiration when the head is fixed.
What is Erb’s point?
An area halfway along the posterior border of the sternocleidomastoid muscle that the cutaneous branches of the cervical plexus emerge; the accessory nerve is also just deep to the investing fascia at this point.
What are the cutaneous branches of the cervical plexus?
The transverse cervical nerve, the great auricular nerve, the lesser occipital nerve, and the supraclavicular nerve
Transverse cervical nerve
From ventral rami of C2-3; cutaneous nerve to throat
Great auricular nerve
From ventral rami of C2-3; cutaneous to area around ear
Lesser occipital nerve
From ventral rami of C2 (and sometimes C3); cutaneous to skin near the mastoid process
Supraclavicular nerve
From ventral rami of C3-4; splits into three branches - anterior, middle, and posterior; cutaneous to area over clavicle