Neck Triangles (A13) Flashcards
All neck triangles are on both sides therefore there are two of each, which is the exception
sub mental
division of neck triangles
- posterior
- anterior
4 types anterior neck triangles
- submandibular
- submental
- muscular
- carotid
posterior neck triangle: 1-borders 2-apex 3-roof 4-floor 5-contents
1-posterior border of SCM , middle third of clavicle, anterior border of trapezius
2-point between anterior border of trapezius and posterior border of SCM SUPERIORLY at the base of the skull on superior nuchal line
3-investing layer of deep fascia
4-deep cervical fascia covering muscles (prevertebral fascia)
5-(spinal) accessory nerve (CNXI)
origin of spinal accessory nerves (CNXI)
-mostly arise from spinal cord rather than the base of the brain
borders of posterior neck triangle
posterior border of SCM , middle third of clavicle, anterior border of trapezius
apex of posterior neck triangle
point between anterior border of trapezius and posterior border of SCM SUPERIORLY at the base of the skull
roof of posterior neck triangle
investing layer of deep fascia
floor of posterior neck triangle
deep cervical fascia covering muscles (prevertebral fascia)
contents of posterior neck triangle
(spinal) accessory nerve (CNXI)
route of (spinal) accessory nerves from spinal cord to muscles
- branches from C1-4 (can be C5/6 too) anterior spinal nerve roots pass up and over foramen magnum to enter cranial cavity and join with vagus
- traverses the posterior cranial fossa to reach the jugular foramen, briefly meets the cranial portion of the accessory nerve, before exiting the skull (along with the glossopharyngeal and vagus nerves) through jugular foramen and splits to supply 2 muscles
- outside the cranium, the spinal part descends along the internal carotid artery to reach the sternocleidomastoid muscle, which it innervates. It then moves across the posterior triangle of the neck to supply motor fibres to the trapezius.
which 2 muscles are supplied by the (spinal) accessory nerve and which type of innervation is this
- SCM and trapezius (SOMATIC MOTOR innervation only)
- enters the deep surface of both muscles
clinical testing of (spinal) accessory nerves
test the movements that the muscles they innervate carry out:
-movement of head to side and look up (SCM)
-shrug shoulders (trapezius)
(if patients can do the above movements, the nerve is working)
which type of innervation do you get from dorsal spinal roots
sensory
which type of innervation do you get from anterior spinal roots
motor innervation
anterior neck triangle (as a whole): 1-borders 2-apex 3-roof 4-floor 5-contents
1-inferior border of mandible, anterior border of SCM muscles, clavicle (and midline divides further)
2-jugular notch
3-subcutaneous tissue with platysma
4-pharynx, larynx and thyroid gland
5-discussed more within each individual anterior neck triangle division (submandibular, submental, muscular and carotid triangles)
what divides the anterior neck triangle in two (left and right)
anterior midline of the neck
what does the hyoid bone divide anterior triangles into
- suprahyoid triangles (above)
- infrahyoid triangles (below)
suprahyoid triangles
- submental triangle
- submandibular triangles
which bone in the body doesn’t attach to any other bone (floating bone)
hyoid bone