Ps2017 - Cga - Lab 6 (Posterior Triangle Of The Neck)

Front 1

Transverse cervical artery (source, course)

Back 1

Source: Usually a branch of the thyrocervical trunk but may also arise directly from the subclavian artery

Course: Runs through the posterior triangle of the neck anterior to the anterior scalene muscle to reach the deep surface of the trapezius muscle; the transverse cervical artery is accompanied by the spinal accessory nerve and may give rise to the dorsal scapular artery

Front 2

Dorsal scapular artery (source, course)

Back 2

Source: Can be a branch of either the subclavian artery or the the transverse cervical artery

Course: Runs through the posterior triangle of the neck to first reach the deep surface of the levator scapulae; as the artery descends it then passes deep to the rhomboid major and minor muscles; the artery is accompanied by the dorsal scapular nerve; anastomoses with both the suprascapular and circumflex scapular arteries.

Front 3

Subclavian artery (source, course, branches - from Wikipedia, not from glossary, since there's no entry in the glossary)

Back 3

Source: Arises from the aortic arch (left side of the body), or from brachiocephalic artery (right side of the body) when it bifurcates into the right subclavian artery and the right common carotid artery.

Course: Travels laterally between the anterior and middle scalene muscles. As the subclavian artery reaches the lateral border of the first rib, it becomes the axillary artery.

Branches: Vertebral artery, Internal thoracic artery, Thyrocervical trunk, Costocervical trunk, Dorsal Scapular artery (mnemonic: VITamin C and D)

Front 4

Sternocleidomastoid (attachments, innervation, actions)

Back 4

Superior Attachment: Lateral surface of mastoid process extending posteriorly to superior nuchal line

Inferior Attachments: Sternal head - Anterior surface of the manubrium of the sternum; Clavicular head - Medial 1/3 of the clavicle

Innervation: Spinal accessory nerve (XI) and some cervical branches

Actions: Bilateral - Flexion of the neck and extension at the atlanto-occipital joint; Unilateral - Lateral flexion of the head and neck toward the same side with rotation toward the opposite side

Front 5

Platysma muscle (attachments, innervation, action)

Back 5

Superior Attachments: Inferior border of the mandible; Skin and subcutaneous tissue overlying much of the mandible

Inferior Attachment: Fascia covering the upper chests and shoulder

Innervation: Facial nerve (VII)

Action: Pulls skin of neck superiorly and helps depress the corners of the mouth

Front 6

Anterior scalene (attachments, innervation, action)

Back 6

Superior Attachments: Cervical vertebrae (transverse processes)

Inferior Attachment: Rib 1

Innervation: Cervical spinal nerves

Action: Bilateral - Flexion of the neck or elevation of the ribs; Unilateral - Lateral flexion of the neck

Front 7

Middle scalene (attachments, innervation, action)

Back 7

Superior Attachments: Cervical vertebrae (transverse processes)

Inferior Attachment: Rib 1

Innervation: Cervical spinal nerves

Action: Bilateral - Flexion of the neck or elevation of the ribs; Unilateral - Lateral flexion of the neck

Front 8

Subclavius muscle (attachments, innervation, action)

Back 8

Proximal Attachment: First costal cartilage

Distal Attachment: Middle 1/2 of the clavicle

Innervation: Nerve to subclavius (literally, that's what it's called. I had to Wikipedia to make sure this wasn't a mistake. Although the much more normal-sounding "subclavian nerve" is also accepted nomenclature.)

Action: Stabilization and depression of the clavicle

Front 9

Spinal accessory nerve (XI) (origin, muscles innervated, skin innervated, path)

Back 9

Origin: Formed from branches of the upper 5 or 6 levels of the spinal cord.

Muscles Innervated: Trapzeius & sternocleidomastoid

Skin Innervated: None

Path: The spinal accessory nerve goes superiorly adjacent to the spinal cord and between the dorsal and ventral rami, it goes through the foramen magnum entering the skull and then leaves the skull by the jugular foramen where it will run on the deep surface of the sternocleidomastoid. At the posterior border of the sternocleidomastoid the nerve runs through the posterior triangle of the neck (lateral cervical region) to reach the deep surface of the trapezius. Within the posterior triangle, the spinal accessory nerve is joined by branches of the cervical plexus

Front 10

Great auricular nerve (origin, muscles innervated, skin innervated, path)

Back 10

Origin: A cutaneous branch of the cervical plexus

Muscles Innervated: None

Skin Innervated: Skin inferior to the external ear, covering the mastoid process, posterior part of the jaw, ear lobe & much of the external ear

Path: Becomes superficial at the anterior edge mid-way along the length of the sternocleidomastoid muscle (nerve point or punctum nervosum); runs superiorly on the surface of the sternocleidomastoid.

Front 11

Lesser occipital nerve (origin, muscles innervated, skin innervated, path)

Back 11

Origin: A cutaneous branch of the cervical plexus

Muscles Innervated: None

Skin Innervated: Skin of the upper neck & head posterior to the external ear

Path: Becomes superficial at the anterior edge mid-way along the length of the sternocleidomastoid muscle (nerve point or punctum nervosum); runs superiorly and posteriorly to the area posterior of the external ear.

Front 12

Transverse cervical nerve (origin, muscles innervated, skin innervated, path)

Back 12

Origin: A cutaneous branch of the cervical plexus

Muscles Innervated: None

Skin Innervated: Skin of the anterior neck

Path: Becomes superficial at the anterior edge midway along the length of the sternocleidomastoid muscle (nerve point or punctum nervosum); runs transversely on the surface of the sternocleidomastoid

Front 13

Supraclavicular nerves (origin, muscles innervated, skin innervated, path)

Back 13

Origin: A cutaneous branch of the cervical plexus

Muscles Innervated: None

Skin Innervated: Skin of the lower lateral neck, shoulder & upper thoracic wall

Path: Becomes superficial at the anterior edge mid-way along the length of the sternocleidomastoid muscle (nerve point or punctum nervosum); runs transversely on the surface of the sternocleidomastoid

Front 14

Phrenic nerve (origin, muscles innervated, skin innervated, path)

Back 14

Origin: A nerve formed by branches of the ventral rami of the C3, 4 & 5 (it is not considered part of the cervical or brachial plexus)

Muscle Innervated: Diaphragm

Skin Innervated: None

Path: Passes from the neck to the thorax by running inferiorly on the anterior scalene muscle

Front 15

External jugular vein (source, course)

Back 15

Source: The external jugular vein originates from the union of the retromandibular and posterior auricular veins.

Course: The vein descends on the superficial surface of the sternocleidomastoid muscle; it then enters the posterior triangle of the neck where it is a tributary of the subclavian vein

Front 16

Subclavian vein (source, course)

Back 16

Source: The subclavian vein is a continuation of the axillary vein; the transition occurs at the lateral border of the first rib.

Course: The vein runs through the posterior triangle of the neck anterior to the anterior scalene muscle; it then combines with the internal jugular vein to become the brachiocephalic vein.