Triangles of Neck and Clinical Correlation by Dr. RIG.pptx

Triangles of Neck

1. Triangles of Neck Dr. Rabia Inam Gandapore Assistant Professor Head of Department Anatomy (Dentistry-BKCD) B.D.S (SBDC), M.Phil. Anatomy (KMU), Dip. Implant (Sharjah, Bangkok, ACHERS) , CHPE (KMU),CHR (KMU), Dip. Arts (Florence, Italy )

2. Teaching Methodology LGF (Long Group Format) SGF (Short Group Format) LGD (Long Group Discussion, Interactive discussion with the use of models or diagrams) SGD (Short Group) SDL (Self-Directed Learning) DSL (Directed-Self Learning) PBL (Problem- Based Learning) Online Teaching Method Role Play Demonstrations Laboratory Museum Library (Computed Assisted Learning or E-Learning) Assignments Video tutorial method

3. Goal/Aim (main objective) To help/facilitate/augment the students about the : Describe superficial fascia & deep fascia. Enlist subdivisions of anterior triangle of neck a . Submental Triangle b . Digastric triangle c . Carotid Triangle d . Muscular Triangle Describe boundaries & content of anterior triangle of neck. Describe boundaries & content of carotid triangle of neck . Describe boundaries & content of muscular triangle Describe attachments, nerve supply & actions of infrahyoid muscles . Enumerate clinical problems related to anterior neck region. Describe boundaries, divisions & contents of posterior triangle . Discuss swelling of supraclavicular lymph nodes .

4. Specific Learning Objectives (cognitive) At the end of the lecture the student will able to: Describe superficial fascia & deep fascia. Enlist subdivisions of anterior triangle of neck a. Submental Triangle b. Digastric triangle c. Carotid Triangle d. Muscular Triangle Describe boundaries & content of anterior triangle of neck. Describe boundaries & content of carotid triangle of neck. Describe boundaries & content of muscular triangle Describe attachments, nerve supply & actions of infrahyoid muscles. Enumerate clinical problems related to anterior neck region. Describe boundaries, divisions & contents of posterior triangle . Discuss swelling of supraclavicular lymph nodes .

5. Psychomotor Objective: (Guided response) A student to draw labelled diagram of the triangles of neck

6. Affective domain To be able to display a good code of conduct and moral values in the class. To cooperate with the teacher and in groups with the colleagues. To demonstrate a responsible behavior in the class and be punctual, regular, attentive and on time in the class. To be able to perform well in the class under the guidance and supervision of the teacher. Study the topic before entering the class. Discuss among colleagues the topic under discussion in SGDs. Participate in group activities and museum classes and follow the rules. Volunteer to participate in psychomotor activities. Listen to the teacher's instructions carefully and follow the guidelines. Ask questions in the class by raising hand and avoid creating a disturbance. To be able to submit all assignments on time and get your sketch logbooks checked.

7. Lesson contents Clinical chair side question: Students will be asked if they know what is the function of triangles of neck Outline: Activity 1 The facilitator will explain the student's Triangles of Neck in detail Activity 2 The facilitator will ask the students to locate triangles of Neck on Model Activity 3 The facilitator will ask the students a few Multiple Choice Questions related to it with flashcards.

8. Recommendations Students assessment: MCQs, Flashcards, Diagrams labeling. Learning resources: Langman’s T.W. Sadler, Laiq Hussain Siddiqui, Snell Clinical Anatomy , Netter’s Atlas , BD Chaurasia’s Human anatomy, Internet sources links.

9. Introduction S ide of neck presents a quadrilateral outline. Its limited: Above: by lower border of body of mandible & an imaginary line drawn from angle of mandible to mastoid process. Below: limited by upper border of clavicle . Medially: by midline of neck . Posteriorly: by anterior border of Trapezius muscle .

10. Sternocleidomastoid & Trapezius Muscles L arge superficial muscles of neck . Both of them are supplied by spinal root of accessory nerve .

11. Sternocleidomastoid This quadrilateral space is divided by Sternocleidomastoid muscle into 2 triangles . It passes obliquely upwards and backwards from its site of origin at clavicle & sternum to its point of insertion on the mastoid process & occipital bone . The triangle in front of this muscle is the anterior triangle & behind it is the posterior triangle .

12. Sternocleidomastoid Origin: 1. Sternal head arises from superolateral part of front of manubrium sterni . 2. Clavicular head arises from medial 1/3rd of superior surface of clavicle . Between two heads, there is a small triangular depression of lesser supraclavicular fossa , overlying internal jugular vein

13. Insertion: 1. By a thick tendon into lateral surface of mastoid process , from its tip to superior border. 2. By a thin aponeurosis into lateral half of superior nuchal line of occipital bone . Nerve Supply: 1. Spinal accessory nerve ( motor supply). It passes through muscle. 2. Branches from ventral rami of C2 & C3 are proprioceptive . Blood Supply Arterial supply: one branch each from superior thyroid artery & suprascapular artery and, two branches from occipital artery supply big muscle. Veins: follow arteries

14. Actions: 1. Unilateral contracts: a . It turns chin to opposite side . b . It can also tilt head to wards shoulder of same side . 2. Bilateral contract together: a . They draw the head forwards , as in eating & in lifting head from a pillow. b . With longus colli , they flex the neck against resistance. c . It also helps in forced inspiration

15. Relations : sternocleidomastoid is enclosed in investing layer of deep cervical fascia & is pierced by accessory nerve & four sternocleidomastoid arteries . It has following relations. Superficial: 1. Skin 2. Superficial fascia & Superficial lamina of deep cervical fascia 3. Platysma 4. External jugular vein & superficial cervical lymph nodes. 5. Cervical Plexus: Great auricular, Transverse or anterior cutaneous, Medial supraclavicular nerves & Lesser occipital nerve 6. P arotid gland overlaps muscle. Deep: 1 Bones and joints: Above: Mastoid process, Below: Sternoclavicular joint 2 Carotid sheath 3 Muscles: Sternohyoid , Sternothyroid , Omohyoid , 3 scalene, Levator scapulae, Splenius capitis , Longissimus capitis , Posterior belly of digastric.

16. 4. Arteries: Common carotid (Internal carotid & External carotid), Sternocleidomastoid arteries (2 from occipital artery, 1 from superior thyroid , 1 from suprascapular ), Occipital, Subclavian , Suprascapular & Transverse cervical 5. Veins: Internal jugular , Anterior jugular, Facial, Lingual 6. Nerves: Vagus , Parts of IX (GP), XI (SA), XII (HG), Cervical plexus ( Ansa cervicalis & Phrenic), Upper part of brachial plexus,, 7. Lymph nodes: superficial & deep cervical .

17. Clinical Relevance Sucide attempts fail as it’s a thick muscle protecting the underlying structures. And only succeed if greater part of sternocleidomastoid muscle & larynx have been severed

18. Torticollis Spasmodic Torticollis (Twisted-Neck Collar): deformity in which head is bent to one side & chin points to other side. Cause: spasm or contracture of muscles supplied by spinal accessory nerve , these being sternocleidomastoid & trapezius. Many Types of torticollis but common types are: a. Rheumatic torticollis: due to exposure to cold or draught. b. Reflex torticollis: due to inflamed or suppurating cervical lymph nodes which irritate spinal accessory nerve.

19. Anterior Triangle Of Neck

20. Boundaries Posteriorly (Lateral) By: Ant border of Sternocleidomastoid Anteriorly (Medial) By: Midline of Neck Superiorly By: Lower Margin of body of mandible Coverings: Skin , Superficial Fascia , Platysma & Investing layer of deep fascia running across the triangle in this coverings are cervical branch of facial nerve & transverse cutaneous nerve . S ub- divided into smaller triangles by: Anterior & Posterior bellies of digastric muscle Superior belly of omohyoid muscle

21. a. Submental Triangle M edian triangle Boundries : Anteriorly: Midline of the neck Laterally: Anterior belly of digastric Inferiorly (base): Body of hyoid bone Floor: Mylohyoid muscle & median raphe attached Apex : lies below the chin- Contents 4 Submental Lymph Node (superficial fascia) D rains: lower lip, gums, floor of mouth, tip of tongue

22. b. Diagastric Triangle Boundries Anterio -inferior: Anterior belly of digastric Posterio -inferior: Posterior belly of Digastric & Stylohyoid Superiorly (base): Lower border of body of Mandible Floor: Mylohyoid (anterior) & Hyoglossus muscle (Posterior), part of middle constrictor muscle of pharynx Roof: skin, superficial fascia ( Platysma , Cervical branch of facial nerve, ascending branch of anterior/transverse cutaneous nerve, deep fascia splits to enclose submandibular gland

23. Contents Anterior part : submandibular salivary gland, Facial artery & vein , Submandibular Lymph nodes. Hypoglossal nerve, Nerves & Vessels to Mylohyoid Muscle, submental artery Posterior part: Carotid sheath with carotid arteries, Internal jugular vein, Vagus nerve, Lower part of parotid gland projects into triangle

24. c. Carotid triangle It lies behind the hyoid bone Boundries Anterio -Superiorly: Posterior belly of digastric & stylohoid Anterio -Inferiorly: Superior belly of Omohyoid Posteriorly: Anterior border of sternocleidomastoid Floor: Portion of thyrohyoid muscle, Hyoglossus , middle & inferior constrictor muscle of pharynx Roof: Skin, Superficial fascia ( Platysma , Cervical branch of facial nerve, transverse cutaneous nerve, investing layer of deep cervical fascia

25. Floor of carotid triangle

26. Contents: Arteries: Carotid sheath with dividing carotid artery into internal & external carotid artery (superior thyroid, lingual, facial, ascending pharyngeal and occipital branches) Veins: internal jugular vein (  common facial vein, pharyrgeal vein, lingual vein) Nerves : Hypoglossal nerve, Internal & external laryngeal nerve, Accessory & vagus nerves, spinal nerve, Lymph nodes: part of chain of deep cervical lymph nodes Contents of carotid triangle

27. d. Muscular Triangle It lies below hyoid bone Boundaries Anteriorly: Midline of neck (Hyoid bone to sternum) Posterio -Superiorly: Superior belly of omohyoid Posterio -Inferiorly: Anterior border of sternocleidomastoid Floor (Contents): Sternohyoid & Sternothyroid , Beneath the floor lies thyroid gland ( Thyrohyoid ) , larynx , trachea & esophagus, Omohyoid

28. Posterior Triangle Of Neck

29. Boundaries Features: S pace on side of neck situated behind sternocleidomastoid Boundaries: Posteriorly: Anterior border of trapezius muscle. Anteriorly: Posterior border of sternocleidomastoid muscle Inferiorly: M iddle 1/3 rd of clavicle Apex: Lies on superior nuchal line where trapezius & sternocleidomastoid meet Floor: Prevertebral layer of deep cervical fascia, covering following muscles: 1. Splenius capitis 2. Levator scapulae 3. Scalenus ( Posterior,Middle,Anterior ) 4. Semispinalis capitis

30. Roof : Investing layer of deep cervical fascia. S uperficial fascia over posterior triangle contains: 1. Platysma 2. External jugular & posterior external jugular veins 3. Parts of supraclavicular, great auricular, transverse cutaneous & lesser occipital nerves 4. Unnamed arteries derived from occipital , transverse cervical & suprascapular arteries. 5. Lymph vessels which pierce deep fascia to end in supraclavicular nodes.

31. External Jugular Vein It lies deep to platysma . It is formed by union of posterior auricular vein with posterior division of retromandibular vein . It begins within lower part of parotid gland , crosses sternocleidomastoid obliquely , pierces antero -inferior angle of roof of posterior triangle & opens into subclavian vein . Its tributaries are: a. Posterior external jugular vein b. Transverse cervical vein c . S uprascapular vein d . A nterior jugular vein O blique jugular vein connects external jugular vein with internal jugular vein across middle 1/3rd of anterior border of sternocleidomastoid .

32. Posterior Triangle Of Neck (Sub-divisions) P osterior triangle of neck is subdivided by inferior belly of omohyoid muscle into : 1). Above: Large Occipital 2 ). Below: Small S upra- Clavicular triangle

33. 1). Occipital Triangle O ccipital triangle: larger division of posterior triangle, is bounded Infront : by sternocleidomastoid Behind: by Trapezius Below: by inferior belly of omohyoid Its Floor: is formed from above downward by splenius capitis , Levator scapulae & scaleni medius & posterior . Its covered : by skin, superficial & deep fascia and platysma below. R oof : cutaneous nerves of cervical plexus, external jugular vein & platysma muscle

34. 2. Supra Clavicular Triangle S ubclavian triangle (or supraclavicular triangle , omoclavicular triangle): smaller division of posterior triangle is bounded Above: by inferior belly of omohyoid Below: by clavicle Base: posterior border of sternocleidomastoid

35. Contents A). Nerves & Plexuses: OCCIPITAL TRIANGLE: 1 ). S pinal accessory nerve (Cranial Nerve XI) 2 ). Four cutaneous Branches of cervical plexus ( Transverse cutaneous nerve, Supraclavicular nerves, Great auricular nerve, Lesser occipital) 3 ). Muscular branches to levator scapulae (C3, C4), trapezius (C3, C4), Nerve to rhomboid or dorsal scapular nerve ( C5) 4). C5, C6 roots of brachial plexus SUB-CLAVIAN TRIANGLE: 4).Nerves to serratus anterior (C5–C7 ), subclavius (C5, C6), Suprascapular (C5 , C6) 5 ). Roots & trunks of Brachial Plexus 6). Phrenic Nerve (C3,4,5)

36. B ). Vessels: 1 ). S ubclavian artery (3 rd part ) & Vein 2 ). Transverse cervical artery & Vein 3 ). Suprascapular artery & Vein 4 ). Terminal part of external jugular vein 5). Occipital artery 6). Lower part of external jugular vein C). Lymph Nodes 1). Occipital 2). Supraclavicular D) Muscles: 1). Inferior belly of Omohyoid muscle 2). Anterior scalene 3). Middle scalene 4). Posterior scalene 5). Levator scapulae muscle 6). S plenius muscle

37. Clinical Relevance

38. Enlargement of supraclavicular lymph nodes M ost common swelling in posterior triangle is due to enlargement of supraclavicular lymph nodes . While biopsy of lymph node, careful preserve accessory nerve which may get entangled amongst enlarged lymph nodes. C ommonly enlarged in: 1. Tuberculosis , 2. Hodgkin’s disease 3. Malignant growths of breast , arm or chest.

39. Block dissection of neck for malignant diseases is removal of cervical lymph nodes along with other structures involved in growth . This procedure does not endanger those nerves of posterior triangle which lie deep to prevertebral fascia , i.e . brachial & cervical plexuses and their muscular branches.

40. Compression of Subclavian Artery A cervical rib may compress second part of subclavian artery. In these cases, blood supply to upper limb reaches via anastomoses around scapula . Second part of subclavian artery may get pressed by scalenus anterior muscl e, resulting in decreased blood supply to upper limb. If muscle is divided , effects are abolished

41. Dysphagia lusoria C aused by compression of oesophagus by an abnormal subclavian artery is called dysphagia lusoria .

42. A neurysms , AV fistulae or arteriosclerotic occlusions Elective arterial surgery of common carotid artery is done for aneurysms, AV fistulae or arteriosclerotic occlusions. It is better to expose common carotid artery in its upper part where it is superficial . While ligating artery , care should be taken not to include vagus nerve or sympathetic chain.

43. Muscles of Neck

44. Muscle Origin Insertion Nerve Supply Action 1 Platysma Deep fascia over pectoralis major and deltoid Body of mandible and angle of mouth Facial nerve cervical branch Depresses mandible & angle of mouth 2 Sternocleidomastoid Manubrium sterni and medial third of clavicle Mastoid process of temporal bone & occipital bone Spinal part of accessory nerve & C2, C3 Two muscles acting together extend head & flex neck; one muscle rotates head to opposite side 3 Digastric - Posterior belly Mastoid process of temporal bone Intermediate tendon is held to hyoid by fascial sling Facial nerve Depresses mandible or elevates hyoid bone Digastric- Anterior belly Body of mandible Nerve to mylohyoid

45. Muscle Origin Insertion Nerve Supply Action 4 Stylohyoid Styloid process Body of hyoid bone Facial nerve Elevates hyoid bone 5 Mylohyoid Mylohyoid line of body of mandible Body of hyoid bone & fibrous raphe Inferior alveolar nerve Elevates floor of mouth & hyoid bone or depresses mandible 6 Geniohyoid Inferior mental spine of mandible Body of hyoid bone 1st cervical nerve Elevates hyoid bone or depresses mandible 7 Sternohyoid Manubrium sterni & clavicle Body of hyoid bone Ansa cervicalis ; C1, 2 & 3 Depresses hyoid bone 8 Sternothyroid Manubrium sterni Oblique line on lamina of thyroid cartilage Ansa cervicalis ; C1, 2, and 3 Depresses larynx 9 Thyrohyoid Oblique line on lamina of thyroid cartilage Lower border of body of hyoid bone 1st cervical nerve Depresses hyoid bone or elevates larynx 10 Inferior belly Omohyoid Upper margin of scapula and suprascapular ligament Intermediate tendon is held to clavicle and first rib by fascial sling Ansa cervicalis ; C1, 2, and 3 Depresses hyoid bone Superior belly Omohyoid Lower border of body of hyoid bone

46. Muscle Origin Insertion Nerve Supply Action 11 Scalenus anterior Transverse processes of 3rd, 4th, 5th, & 6th cervical vertebrae 1st rib (Scalene tubercle) Anterior rami C4, C5, C 6 Cervical nerves Elevates 1st rib; laterally flexes & rotates cervical part of vertebral column 12 Scalenus medius Transverse processes of atlas & upper 5 cervical vertebrae Anterior rami of lower cervical nerves 13 Scalenus posterior (absent or blended with Scalenus medius ) Transverse processes of lower cervical vertebrae 2nd rib Elevates 2nd rib; laterally flexes & rotates cervical part of vertebral column

47. Thank You

48. Test?

49. Scalenus anterior Lateral part of Neck Anteriorly: subclavian artery Posteriorly: Phrenic nerve Relations: Medially: Vertebral artery & vein, sympathetic trunk,thoracic duct (Left side) Laterally: Emerging branch of cervical plexus, roots of brachial plexus, 3 rd part of subclavian artery Anteriorly: Preverebral layer of deep cervical fascia , Clavicle, subclavius , Carotid arteries,Vagus nerve, Internal Jugular vein,deep cervical lymph nodes, sternocleidomastoid  &  omohyoid muscle. Lateral part of carotid sheath, transverse cervical, suprascapular & ascending cervical arteries,  subclavian vein. C3 to C5 spinal roots which form phrenic nerve right on anterior surface of scalenus anterior. Posteriorly : suprapleural membrane, cervical pleura , roots of brachial plexus  & subclavian artery (2 nd part).