Deep fascia of Neck

introduction of neck and boundaries of neck , superficial fascia and structures present with in it, deep cervical fascia types and most importantly spaces with in it mainly about Retro-pharyngeal spaces and applied anatomy along with incision markings.

1. Deep fascia of the neck

2. Contents Introduction Boundaries Superficial fascia Layers of Deep fascia Spaces around the neck Applied anatomy

3. Introduction Neck is the transition and conducting zone between head and rest of the body It holds important viscera of the endocrine, respiratory and digestive systems The structure occupying the neck are crowded : as there is no bony covering or cage, these structures also are prone to injury and damage.

4. Contd. The subcutaneous tissue nerves, veins of the neck, The main anatomical potential space in the neck which lead to Spread of infections to the mediastinum . Four major fascial compartments of the neck Where the viscera of the neck are located.

5. The Neck lies between lower margin of mandible above & base of cranium suprasternal notch & upper border of clavicle below/ superior thoracic aperture It is strengthened by cervical part of vertebral column, is convex forward supports skull. Behind the vertebrae is ………….. a mass of extensor muscles In front is ……………………………….. a smaller group of flexor muscles . In central region are :………………… parts of respiratory system, larynx & trachea , behind are parts of alimentary system, pharynx & esophagus.

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

7. 4 Compartments The midline visceral compartments Midline musculo -skeletal compartment Right and left neuro -vascular compartment

8. At sides of these structures are vertically running : carotid arteries, internal jugular veins, vagus nerve, deep cervical lymph nodes

9. Landmarks of the neck Sternocleidomastoid Suprasternal fossa Greater supraclaviclar fossa

10. Landmarks of the neck Hyoid bone Thyroid cartilage Cricoid cartilage

11. The natural line of cleavage of the skin are constant and run almost horizontally around the neck

12. Fascia of Neck

13. 1-Superficial Fascia 2-deep Fascia

14. Superficial Fascia

15. Superficial Fascia forms a thin layer and has no specific features Antero-lateral aspects on both sides encloses Platysma muscle. embedded in it are : cutaneous nerves, superficial veins, superficial lymph nodes. Especially in females fat tissue present.

16. Ext. jugular Int. jugular Ant. jugular Sup. thyroid Middle thyroid Inf. thyroid

17. Structures in neck: are surrounded by a layer of subcutaneous tissue (superficial fascia) are compartmentalized by layers of deep cervical fascia. fascial planes determine direction in which an infection in neck may spread. Cervical Subcutaneous Tissue & Platysma superficial cervical fascia is a layer of fatty connective tissue lies between dermis of skin & investing layer of deep cervical fascia It is usually thinner than in other regions, anteriorly . Platysma …….. Anterolaterally

18. external jugular vein (EJV) Descending from angle of mandible to middle of clavicle are superficial to main cutaneous nerves of neck. covers anterolateral aspect of neck . Help to measure CVP

19. Platysma / Musculus platysma myoids /subcutaneous collis / Tetragonus . Flat plate is a broad, thin sheet of muscle in subcutaneous tissue of neck and it is a remnant of Panniculosus carnosus . is supplied by cervical branch of CN VII. Its fibers arise in deep fascia covering superior parts of deltoid & pectoralis major muscles sweep superomedially over clavicle to inferior border of mandible and merge with fascia of the face . anterior borders of the two muscles decussate over chin blend with facial muscles . Inferiorly , fibers diverge, leaving a gap anterior to larynx & trachea

20. tenses skin, producing vertical skin ridges Expression of horror, tension and stress releasing pressure on superficial veins. use in shaving It is a muscle of grimace. depress the mandible and draw corners of mouth inferiorly Acting its inferior attachment Its superficial to all structures. 2 bones and doesn’t cover upper part of the anterior triangle but lower part covers and the posterior triangle .

21. Contents Platysma Superficial veins Anterior jugular v. External jugular v. Cutaneous nerves Lesser occipital n. Greator auricular n. Transverse nerve of neck Supraclavicular n. Cervical branch of facial n.

22. Regions of neck Neck Anterior region of neck Sternocleidomastoid region Lateral region of neck

23. Triangles of posterior (l ateral) region of neck Occipital triangle supraclavicular triangle (greater supraclavicular fossa)

24. Deep Cervical Fascia / colli

25. Deep Cervical Fascia: Investing Layer Pretracheal layer Prevertebral layer.

26. support : Viscera (thyroid gland) Muscles Vessels Deep lymph nodes condenses around : ……… to form carotid sheath Common carotid arteries, Internal jugular veins (IJVs) Vagus nerves form natural cleavage planes tissues may be separated during surgery, limit the spread of abscesses (collections of pus) Afford slipperiness allows structures in neck to move and pass over one another without difficulty, swallowing and turning the head and neck .

27. Deep Cervical Fascia: Investing layer

28. Investing Layer/external layer/lamina superficialis Investing = complete covering most superficial fascial layer, surrounds entire neck deep to skin and subcutaneous tissue. splits into superficial and deep layers to enclose (invest) : Trapezius & Sternocleidomastoid (SCM) muscles. Superiorly, attaches to : External occipital protuberanace,Superior nuchal line of occipital bone. Mastoid processes of temporal bones. Zygomatic arches. Inferior border of mandible. Hyoid bone. Spinous processes of cervical vertebrae . also splits to enclose : submandibular gland; Posterior to mandible,it splits to form fibrous capsule of parotid gland .

29. Investing Layer stylomandibular ligament is a thickened modification Inferiorly, attaches to : manubrium, clavicles, & acromions spines of scapulae. continuous posteriorly with : Periosteum covering C7 spinous process nuchal ligament a triangular membrane forms a median fibrous septum between muscles of two sides of neck

30. Horizontal disposition This traced from posterior attachment, it splits to enclose the trapezius and it form a single layer that forms the roof of the posterior triangle In its lower attachment it splits twice to enclose 2 spaces Above the manubrium sterni it splits into 2 Anterior layer attaches to anterior border of manubrium sterni and posterior layer to posterior border Space called supra- sternal space of Burns. contents :- sternal head of SCM and anterior jugular vein, jugular venous arch , fat and lymph node . above the clavicle near the lower part of roof of the posterior triangle Splits into 2 antero -lateral aspect of the clavicle posterior aspect of the clavicle Space called Supra- clavicular space contents :- EJV. Subclavian vein, supra- clavicular nerves.

31. Vertical disposition Traced upwards it covers sub- mandibular region and enclose the gland Attaches to lower border of mandible and deep layer of mylohyoid line of mandible Posterior to the gland again splits into enclose the parotid gland and attach to zygomatic arch to form parotido masseteric fascia deeper layer goes to Tympanic plate Between angle of mandible and styloid process form stylo-mandibular ligament Spinal XI nerve closely related to this layer.

32. Deep Cervical Fascia: P retrache al/middle cervical fascia/porter’s fascia/ lamina pretrachealis Anterior- thin and encloses thyroid gland and stretches in front of trachea Superior – hyoid bone, arch of cricoid cartilage and oblique line of thyroid cartilage Inferior - passes along the trachea , superior mediastinum and mergs with fibrous pericardium of heart, movements of thyroid gland with deglutition, sibson’s fascia . Laterally – antero -laterally of carotid sheath between 2 lateral limits, the pretracheal layer encloses the infra- hyoid muscles . and they have 2 parts Muscular part and visceral part

33. Posterosuperiorly :- pre-tracheal layer is continues with of the pharynx Ligament of Berry is derived from this fascia and connects the lobes of thyroid gland with cricoid cartilage Dysphagia :- postero -lateral surface of Thyroid lobe is ill- defind .

34. It is limited to the anterior part of neck It extends inferiorly from hyoid into thorax , includes a thin muscular part, encloses : infrahyoid muscles, & a visceral part , encloses thyroid gland, trachea, & esophagus pharynx is continuous posteriorly & superiorly with buccopharyngeal fascia of pharynx .

35. In hyoid, a thickening of pre tracheal fascia forms a pulley or trochlea through intermediate tendon of digastric muscle passes, suspending hyoid . tethers two-bellied omohyoid muscle, redirecting course of muscle between bellies.

36. Prevertebral Layer/ PV Fascia/lamina prevertebralis

37. forms a tubular sheath for vertebral column & muscles associated with it, such as : longus colli & longus capitis anteriorly , scalenes laterally, deep cervical muscles posteriorly is fixed to cranial base superiorly. Anterior :- separated from pharynx and BPF by Retro-pharyngeal space Inferiorly, it blends with endothoracic fascia . fuses centrally with anterior longitudinal ligament at approximately T3/T4 vertebra extends laterally as axillary sheath surrounds axillary vessels & brachial plexus. sympathetic trunks cervical parts are embedded in it

38. Carotid Sheath

39. Submendibular gland Omohyoid Sternohyoid Sternothyroid Superior thyroid a. Cervical plexus Phrenic n. Ansa cervicalis Vagus n. Hypoglossal n. Accessory n. Digastric

40. Condensation of the connective tissue around great vessel and tubular fascial investment extends from cranial base to root of neck. blends : anteriorly with investing and pretracheal layers P osteriorly with prevertebral layer contains : common and internal carotid arteries, internal jugular vein, vagus nerve (CN X), deep cervical lymph nodes, carotid sinus , sympathetic nerve fibers (carotid periarterial plexuses). carotid sheath and pretracheal fascia communicate freely with : mediastinum of thorax inferiorly & cranial cavity superiorly. represent potential pathways for spread of infection and extravasated blood .

41. Superior :- base of skull Inferior :- merge with covering the arch of aorta Posterior :- symphathic trunk Anterior :- ansa cervicalis to carotid sheath Str piercing :- ECA,IJV, IX, XI,XII,X CN AA:- Block dissection of neck, during surgical removal of deep cervical LN

42. Spaces around the Neck Disposition of various layers of fascia result in the formation of the potential tissue spaces in the neck They are not real spaces but are potential In healthy persons- filled with CT in pathologically secretions are noted and there is no tissue barrier, spread of infections They are 2 groups Supra- hyoid spaces Infra- hyoid spaces

43. Supra- hyoid spaces Continuity with regions of head Infra temporal fossa , sub mandibular fossa and tonsillar fossa Above the hyoid are in SM regions of head and pre-vertebral region Spaces around the lower jaw Pharyngeal spaces Pre-vertebral spaces

44. Spaces around lower jaw Sub-mental spaces Sub- mandibular spaces Sub-lingual spaces Retro-pharyngeal space Peri -pharyngeal spaces Peri-tonsilar spaces

45. Sub- mental spa ce :- deep to upper part of inv.layer of DCF and S/F to mylohyoid muscle bounded by anterior belly of digastric muscle Sub- mandibular spaces :- these are paired, deep to concerned half of mandible and both bellys of digastric muscle. Sub-lingual spaces :- lies deep to mylohyoid in the floor of mouth and paired its free communication with sub mental space which is anatomically a cervical tissue space.

46. Retropharyngeal Space

47. It is largest and most important inter- fascial space in neck It is a potential space Lies between visceral part of prevertebral layer of deep cervical fascia and pre-vertebral muscles & buccopharyngeal fascia surrounding pharynx superficially. Inferiorly, buccopharyngeal fascia is continuous with pretracheal layer Sternocleidomastoid Trapezius Deep Cervical Fascia Investing layer of deep cervical fascia Prevertebral fascia Pretracheal fas cia (visceral part) Carotid sheath Buccopharyngeal fascia Alar fascia Pretracheal fascia (muscular part) T E

48. Alar fascia : forms a further subdivision of retropharyngeal space. is attached along midline of buccopharyngeal fascia from cranium to level of the C7 vertebra. it extends laterally and terminates in carotid sheath. permits movement of pharynx, esophagus, larynx, and trachea relative to vertebral column during swallowing. is closed : superiorly by cranial base and on each side by carotid sheath. It opens inferiorly into superior mediastinum Contents :- LCT, retro-pharyngeal LN, pharyngeal Plexuses and vessels. A.A :- Cold abscess and para - median swelling.

49. Peri -pharyngeal/ para pharyngeal space T hese are paired. Location:- on each side of posterolateral aspect of pharynx Medially- sup constrictor muscle of pharynx and palatine tonsil Antero-laterally- medial pterygoid with ramus of mandible Postero -laterally- parotid gland with parotid fascia and communicates with retro-pharyngeal space Posterior – carotid sheath Contents :- branch of maxillary nerve and maxillary artery , fibro-fatty tissue Peri - tonsillar space :- actually a part of intra-pharyngeal space location :- around palatine tonsils and medial surface of superior constrictor.

50. Infra-hyoid spaces They are Pretracheal space, Retro-visceral space, Pre-vertebral space Carotid space

51. Pre- tracheal space/ para tracheal space Location :- behind pre-tracheal fascia and infra-hyoid muscle anterior wall of oesophagus Superior :- infrahyoid muscles to thyroid cartilage Inferior :- space open into superior mediastinum Retro- visceral spaces locaction :- between posterior wall oesophagus and prevertebral fascia Superior :- retro-pharyngeal space Inferior :- superior mediastinum

52. Pre- vertebral space Location :- between prevertebral fascia and vertebral column laterally prevertbral muscle are closely packed can’t extends laterally Superior :- base of skull Inferior :- continues posterior mediastinum Anterior :- prevertebral fascia weakest especially time of infection. Carotid space Space around the contents of carotid sheath Above and below closed because of adhesion of the fascia to the adventitia of vessels.

53. Applied anatomy Arrangements of layers in neck determine the direction of spread of infections in and around the neck Investing layer :- prevents spread of purulent infection from s/f aspect of neck to deep areas of thorax, Pretracheal muscular part doesn’t spread to thorax but visceral part spreads down easily. In Tuberculosis of cervical vertebrae – pus between vertebral column and prevertebral fascia and produce median swelling of posteior wall of pharynx are called chronic retropharyngeal abscess. Infection spread to prevertebral muscles and skin of posterior triangle , axilla and axillary sheath.

54. Contd.., Collar stud abcess :- in tuberculosis deep cervical LN affected. pus spread from superficial to deep. Retro pharyngeal abscess :- retropharyngeal LN gets infected and BPF also infected. Ludwig’s angina :- an infection in sub- mandibular region is limited to a triangular area 2 halves of mandible and hyoid bone Parotid fascia ;- is very dense, infection of parotid gland is very painful.

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