Posterior Cervical Triangle

What broader region is the posterior cervical triangle typically part of?

Lateral Cervical Spine

What is the anterior border of the posterior cervical triangle?

Posterior border of sternocleidomastoid

What is the posterior border of the posterior cervical triangle?

Anterior border of trapezius

What is the inferior border of the posterior cervical triangle?

Middle third of clavicle

What is the apex of the posterior cervical triangle?

Where the sternocleidomastoid and trapezius meet at the superior nuchal line

What is the roof of the posterior cervical triangle?

Investing layer of deep cervical fascia

What is the floor of the posterior cervical triangle?

splenius capitis (superiorly)

Levator Scapulae ( middle portion)

Scalene Muscles (posterior, middle, anterior)

What muscle subdivides the posterior cervical triangle?

Inferior belly of omohyoid muscle

What are the subdivisions of the Posterior cervical triangle?

Occipital triangle ( superior to the omohyoid inferior muscle belly)

Subclavian Triangle( Inferior to the omohyoid inferior muscle belly)

Nerves of Posterior Cervical Triangle

Spinal Accessory Nerve

Roots and trunks of the brachial plexus

Cutaneous nerves ( Lesser occipital nerve C2, greater auricular nerve C2-C3,Transverse cervical nerve C2-C3, Supraclavicular nerves C3-C4)

Vessels of Posterior Cervical Triangle

Subclavian Artery

Transverse cervical artery

Suprascapular artery

External Jugular vein

Platysma

Superior attachment: Inferior Border of mandibula, skin, subcutaneous tissues of lower face

Inferior attachments: Fascia covering superior parts of pec major and deltoid muscles

Innervation: Cervical branch of facial N

Actions: One of the muscle for fascial expressions

Draws corners of mouth inferiorly and widens it as an expressions of sadness and fright

Draws skin of the neck superiorly when teeth are clenched, indicating tension

Sternocleidomastoid

Superior attachment: Lateral surface of mastoid process of temporal, lateral half of superior nuchal line,

Inferior attachment: Sternal head ( anterior surface of manubrium of sternum)

Clavicular Head ( Superior surface of middle third of clavicle)

Innervation: Spinal accessory nerve, C2-C3 nerves for pain and proprioception

Action: Unilaterally- Tilts head toward the same side and rotates it so face is turned superiorly toward opposite side

Bilaterally- Flexes cervical vertebrae so chin approaches manubrium

Extends superior cervical vertebrae so chin is thrust forward

Accessory breathing muscle- Elevate manubrium and medial end of clavicles assisting in deep respiration

Trapezius

Connects pectoral gridle to trunk assisting on suspension of upper extremity to the trunk

O- Medial Third of superior nuchal line, nuchal ligament, spinous processes C7-t12

I- Lateral third of clavicle, acromion and spine of scapula

Inn- CN Xl

A- Upper: Elevation of scapula

Lower: Depression of scapula

Upper+lower: Upward rotation of scapula

All together: scapular retraction

Splenius Capitis

O- Nuchal Ligament, spinous processes of C7-T6

Ins- Superolaterally to mastoid process of temporal bone, lateral third of superior nuchal line of occipital bone

Inn- Posterior rami of spinal nerve

A- Unilaterally: Laterally flexes neck and rotates head to side of active muscles

Bilaterally: Extends head and neck

Anterior scalene

O- Anterior tubercles of transverse processes of C3-C6 vertebrae

I- First rib

Inn- Segmental cervical spinal nerves C4-C6

A- Unilateral contraction: Ipsilateral flexion, contralateral rotation

bilateral contraction: Cervical Spine flexion, accessory muscle of inspiration, elevates 1st rib

Middle Scalene

O- Posterior tubercles of transverse process of C4-C7 vertebrae

Ins- Superior surface of 1st rib

Inn- Anterior rami of cervical spinal nerves C7 and C8

A- Unilateral contraction: Ipsilateral Flexion

Bilateral: Cervical Spine flexion, accessory muscle of inspiration, elevates 1st rib

Posterior Scalene

O- Posterior tubercles of Transverse processes of C4-C6

Ins- External border of 2nd rib

Inn- Anterior Rami of Cervical Spinal Nerve

A- Unilaterally contraction: Ipsilateral Flexion

Bilateral contraction: Elevates 2nd rib