2. Posterior Triangle of the Neck
Dr. Zeenat Zaidi

3. The Neck The region of the body that lies between:
The lower border of mandible &
The suprasternal notch and the upper border of the clavicle

4. Skin
The natural lines of cleavage are constant and run almost horizontally around the neck (an incision along a cleavage line heals as a narrow scar)

5. Superficial Fascia Thin layer of connective tissue Encloses platysma
Contains:
cutaneous nerves
superficial veins
superficial lymph nodes

6. Cutaneous Nerves Back of the neck:
Greater occipital: branch of the posterior ramus of the C2 (C1 has no cutaneous branch)
Front & side of neck: Anterior rami of C2-C4 through branches of cervical plexus
Lesser occipital C2
Great auricular C2-3
Transverse cutaneous C2-3
Supraclavicular C3-4

7. Superficial Veins External Jugular Anterior Jugular Formation
Course & relations
Termination
Tributaries

8. Platysma
Origin: Deep fascia covering pectoralis major and deltoid muscles
Insertion:
Lower margin of the body of mandible
Some fibers blending with the muscle at the angle of the mouth (risoreus)
Below the chin, fibers interdigitate with the fibers of the opposite muscle
Nerve Supply: Cervical branch of the facial nerve
Action: Depresses mandible, draws down the lower lip and the angle of mouth

9. Superficial Lymph Nodes

10. Deep Cervical Fascia

11. Triangles of the Neck

12. Sternocleidomastoid
Origin: Upper part of manubrium & medial third of clavicle
Insertion: Mastoid process & lateral part of superior nuchal line
Nerve supply: Spinal part of accessory nerve (motor) & ventral rami of C2-3 (proprioceptive)
Action:
Both muscles acting together extend head at atlanto-occipital joint, and flex cervical part of vertebral column
Contraction of one muscle moves the face to the opposite side

13. Boundaries Anterior: Posterior border of sternocleidomastoid
Posterior: Anterior border of trapezius
Inferior: Middle third of clavicle
Roof: skin, superficial fascia, platysma, investing layer of deep fascia
Floor: muscles covered by prevertebral fascia

14. Muscular Floor of the Posterior Triangle
From above downward:
Semispinalis capitis
Splenius capitis
Levator scapulae
Scalenus medius
Scalenus anterior may or may not be present

15. Subdivision of the Posterior Triangle
Subdivided by the inferior belly of omohyoid muscle, into:
Large occipital triangle above
Small supraclavicular triangle below

16. Omohyoid Muscle
Two bellies: Superior & Inferior joined by intermediate tendon
Attachement: Superior belly to inferior border of hyoid bone, Inferior belly to superior border of scapula & suprascapular ligament
The Intermediate tendon lies deep to sternocleidomastoid, connected to clavicle & the first rib by a loop of deep fascia
Nerve supply: Ansa cervicalis (C1,2,3)
Superior belly
Intermediate tendon
Inferior belly
Action: Depresses the hyoid bone

17. Contents Arteries: Subclavian (3rd part)
Superficial cervical & suprascapular (branches of thyrocervical trunk, a branch of 1st part of subclavian artery
Occipital, a branch of external carotid artery

18. Veins:
External jugular vein
Formation
Termination
Tributaries

19. Nerves: Branches of cervical plexus Spinal part of accessory nerve
Brachial plexus

20. Clinical Notes Torticollis (wry neck):
Congenital: due to excessive stretching of sternocleidomastoid muscle during labor.
Spasmodic: usually psychogenic
Injury to spinal part of accessory nerve
Injury to brachial plexus
Pleura & Lung injuries in the root of neck
Injury to nerve to platysma

21. Thank You & Good Luck