Posterior triangle of the neck

posterior triangle of neck most important structurenof neck. trunk of brachial plexus is located in this triangle.

1. Posterior Triangle of the Neck

2. Learning objectives At the end of the lecture, the students will be able to:- Describe posterior triangle of neck. List the contents of posterior triangle of neck. List common applied aspects.

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. Triangles of the Neck

5. Posterior Triangle of the Neck

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

7. Boundaries of occipital triangle Inferior belly of omohyoid Sternomastoid trapezius

8. Boundaries of supraclavicular triangle Inferior belly of omohyoid Stenomastoid Middle-third of clavicle

9. Boundaries Anterior: Posterior border of sternocleidomastoid Posterior: Anterior border of trapezius Base: Middle third of clavicle Apex: superior nuchal line of the occipital bone between the attachments of the trapezius and sternomastoid .

10. Platysma m. Investing layer of deep cervical fascia ROOF OF POSTERIOR TRIANGLE

11. CUTANEOUS BRANCHES OF THE CERVICAL PLEXUS Lesser occipital n. (C2,3) Great auricular n.(C2,3) Transverse cervical n. (C2,3 ) Supraclavicular nn . (C3,4) CERVICAL PLEXUS

12. 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

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

14. Veins: External jugular vein Formation Termination

15. Veins: External jugular vein Tributaries

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

17. 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)

18. Sternocleidomastoid 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

19. Trapezius Origin- medial third of superior nuchal line, external occipital protuberence , ligamentum nuchae , spine of seventh cervical vertebra and spines of all thoracic vertebrae.

20. Trapezius Insertion- upper fibers insert into the posterior aspects of lateral third of clavicle. Middle fibers insert into medial aspects of acromian and crest of the spine of scapula. Lower fibers insert into the crest of scapula.

21. Trapezius Action-Upper fibers elevate the scapula along with levator scapulae. Middle fibers cause retraction of scapula along with rhomboids. Lower fibers depresses and medially rotates the scapula.

22. Trapezius Nerve supply: Spinal part of accessory nerve (motor)

23. 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 Nerve supply: Ansa cervicalis (C1,2,3) Superior belly Intermediate tendon Inferior belly Action: Depresses the hyoid bone

24. Clinical Notes Torticollis (wry neck): Congenital : due to excessive stretching of sternocleidomastoid muscle during labor. Injury to spinal part of accessory nerve Injury to brachial plexus Injury to nerve to platysma