POSTERIOR & ANTERIOR TRIANGLE OF NECK Dr . H.A.Jaafar Al- Nahrain University-

1. POSTERIOR & ANTERIOR TRIANGLE OF NECK Dr. H.A.Jaafar Al-Nahrain University- college of Medicine Dept. Of Anatomy

2. Objectives: At the end of this lecture we should be able to know : The boundaries, roof, floor & contents of Anterior triangle The boundaries, contents of posterior triangle The role of Sternomastoid muscle in main anatomical division of the neck. What are the careful and careless area of posterior triangle What are the importance of diagastric and omohyoid muscles as a land marks for subdivision of the two triangular regions of neck.

5. Posterior triangle

6. A. Posterior triangle Is bounded by : posterior border of sternocleidomastoid muscle, anterior border of trapezius muscle, superior border of clavicle. roof ………formed by : platysma investing (superficial) layer of deep cervical fascia. floor :…….formed by : splenius capitis levator scapulae muscles anterior, middle, posterior scalene muscles.

7. Posterior cervical triangle Trapezius Sternocleidomastoid

8. Is divided into :……. by omohyoid posterior belly occipital triangle. subclavian (supraclavicular) triangle. Contains: accessory nerve, cutaneous branches of cervical plexus, external jugular vein, transverse cervical suprascapular vessels, subclavian vein & artery, Inferior belly of omohyoid, roots and trunks of brachial plexus. nerve to subclavius dorsal scapular, suprascapular, long thoracic nerves.

9. Triangles of posterior (lateral) region of neck

10. Triangles of posterior (lateral) region of neck trapezius muscle Sternomastoid muscle

11. Triangles of posterior (lateral) region of neck clavicle Sternomastoid muscle

12. Triangles of posterior (lateral) region of neck • Occipital triangle • supraclavicular triangle (greater supraclavicular fossa)

13. Triangles of posterior (lateral) region of neck • Occipital triangle • supraclavicular triangle (greater supraclavicular fossa)

15. Sternomastoid muscle

16. Sternomastoid muscle trapezius muscle

17. Sternomastoid muscle trapezius muscle clavicle

18. Omohyoidmuscle Sternomastoid muscle trapezius muscle clavicle

19. Omohyoidmuscle Sternomastoid muscle trapezius muscle clavicle Scalenus anterior muscle

20. Omohyoidmuscle Sternomastoid muscle trapezius muscle Scalenus medius muscle clavicle

21. Omohyoidmuscle Sternomastoid muscle trapezius muscle Sterno thyroid m clavicle

22. Omohyoidmuscle Sternomastoid muscle trapezius muscle thyrohyoid m clavicle

23. Omohyoidmuscle Sternomastoid muscle trapezius muscle Sternohyoid m clavicle

24. apex trapeziusmuscle Investing layer of deep fascia roof Sternomastoid muscle Middle 1/3 of clavicle – base

25. Nerves in posterior triangle

26. Spinal part of accessory nerve

27. Platysma

29. Lesser occipital n. External jugular vein Greet auricular n. Transverse nerve of neck Supraclavicular n. Anterior jugular vein Cutaneous nerves and superficial veins

30. Anterior triangle

31. Anterior triangles Suprahyoidmuscles Infrrahyoidmuscles Scalene muscles Prevertebral muscles

32. B. Anterior triangle Is bounded by: anterior border of sternocleidomastoid, anterior midline of neck, inferior border of mandible. roof :……formed by: platysma investing layer of deep cervical fascia. Is further divided by : omohyoid superior belly digastric anterior and posterior bellies into : digastric (submandibular), submental (suprahyoid), carotid, muscular (inferior carotid) triangles.

33. Omohyoidmuscle Sternomastoid muscle

34. Omohyoidmuscle Sternomastoid muscle

35. Omohyoidmuscle Sternomastoid muscle

36. Omohyoidmuscle Sternomastoid muscle

37. apex trapeziusmuscle Investing layer of deep fascia roof Sternomastoid muscle Middle 1/3 of clavicle – base

38. Anterior triangles Suprahyoidmuscles Infrrahyoidmuscles Prevertebral muscles Scalene muscles

39. Posterior belly of digastric Stylohyoid Anterior belly of digastric muscle Sternohyoid muscle

40. Digastric triangle Above …………….lower border of mandible Below & infront …..anterior belly of Digastric muscle Below & behind …..posterior belly of Digastric & stylohyoid muscles . Floor : Anteriorly : ……..mylohyoid muscle Posteriorly ………part of hyoglossusmuscle

41. Contents of Digastric triangle • submandibular salivary gland • submandibular lymph nodes • lie on the surface of the gland • facial artery • deep to posterior end of submandibular salivary gland • facial vein • lies superficial to submandibular salivary gland • hypoglossalnerve • nerve to mylohyoid muscle

42. Anterior belly of digastric Digastric triangle • d Posterior belly of digastric Mylohyoid muscle forms the floor of the mouth

43. Hyoid bone

44. C. Hyoid bone……..Is a U-shaped bone consisting of : a median body, lesser horns (cornua) laterally, …………. paired greater horns (cornua) posteriorly……… paired 1. Body Provides for attachments for : Geniohyoidmuscle, mylohyoid, muscle Omohyoidmuscle, sternohyoidmuscle. 2. Greater horn Provides attachments for : middle constrictor, hyoglossus, digastric (anterior and posterior) bellies, stylohyoid, thyrohyoid muscle. 3. Lesser horn Provides attachment for : stylohyoid ligament, which runs from styloid process to lesser horn

45. Styloid process

46. D. Styloid process Is a slender projection of variable length extends downward & forward from temporal bone. Gives origin to : three muscles: stylohyoid, styloglossus, Stylopharyngeus two ligaments : stylohyoid stylomandibular.

47. Carotid triangle boundary : • Behind : …………..sternomastoid muscle • Infront & above : posteriorbelly of digastric muscle • Infront&below : superior belly of omohyoid muscle Floor : infont : hyoglossus muscle ( above ) and the thyrohyoid muscle (below) • Behind: the middle constrictor muscle of the pharynx (above ) and the inferior constrictor muscle of the pharynx (below )

48. d Posterior belly of digastric Carotid triangle

49. apex trapeziusmuscle Investing layer of deep fascia roof Sternomastoid muscle Middle 1/3 of clavicle – base

50. Internal carotid artery External carotid artery Common carotid artery