Presentation on theme: "Anatomy of neck + innervation of structures"— Presentation transcript:
1Anatomy of neck + innervation of structures Anatomy of neck + innervation of structures. Anatomy (gross and histological) and physiology of the lymphoid system, and of the head and neck –light, clinically relevant summary - DANFrom now I will pay more attention when we formulate FQs because this one sucked
2Contents Neck Fascia Danger Triangle Larynx and Thyroid gland Cervical lymphatic drainage
3Fascia of the NeckStructures in the neck are surrounded by a superficial fascia (subcutaneous tissue)They are compartmentalised by layers of deep cervical fascia.
4The Fascial layers Superficial cervical fascia Deep cervical fascia Thin layer of CT that lies between the dermis of the skin and the investing layer of the deep cervical fasciaCutaneous nerves, blood and lymph vessels, superficial lymph nodes, continous anterolaterally with the platysmaDeep cervical fasciaInvesting layer, pretracheal layer, Prevertebral layer, Alar fascia and carotid sheath
5Neck fascia SUPERFICIAL CERVICAL FASCIA Subcutaneous tissue Investing layerPretracheal layerCarotid sheathPre vertebral lyaerDEEP CERVICAL FASCIARetropharyngeal space
6Investing layerSurrounds: Sternocleoidomastoids, Trapezius, submandibular gland, parotid glandSuperior attachments: Superior nuchal line, mastoid processes, zygomatic arches, inferior border of mandible, hyoid, spinous processes of cervical vertibrae
7Pretracheal layer Includes Continuous with Visceral part (thyroid gland, trachea, oesophagus)Muscular part (infrahyoid muscles)Continuous withCarotid sheaths laterallyBuccopharyngeal fascia posterosuperiorlyPericardium inferiorly
8Carotid Sheath Extends from cranial base – root of neck Continuous Anteriorly: investing and pretracheal layerPosteriorly: Prevertebral layerImportant structures hidden within:Common + internal carotid arteriesIJVCN XDeep cervical nodesCarotid sinus nerveSympathetic nerve fibres
9Pre Vertebral layerFixed to the cranial base superiorly, inferiorly fuses with the anterior longitudinal ligamentForms a tubular sheath for the vertebral column and muscles surrounding it.
10Retropharyngeal space The largest interfascial space in the neck.Potential space that consists of loose connective tissue between the prevertebral layer and the pretracheal layer.The Alar fascia crosses the retropharyngeal spaceAllows the movement of the pharynx, oesophagus, larynx and tracheaMajor pathway for spread of infection
11Neck fascia SUPERFICIAL CERVICAL FASCIA Subcutaneous tissue Investing layerPretracheal layerCarotid sheathPre vertebral lyaerDEEP CERVICAL FASCIARetropharyngeal space
12Importance of Fascia + its layers Spread of infection is limited by facsial boundariesExampleAn Pus abscess posterior to the prevetebral layer may extend laterally in the neck and form a swelling posterior to the SCM. The pus may perforate the prevertebral layer and enter the retropharyngeal space, producing a bulge in the pharynx.Dsyphagia, dysarthria
13Danger triangle of the FACE There is a communication between the facial vein and the cavernous sinus via the via the ophthalmic veins.Bacterial infections can be caused by pus entering the brain's blood supply if pimples in the danger triangle are picked by dirty fingernails.
16Larynx Innervation Blood supply Lymph drainage: Motor: recurrent laryngeal nervesS: superior laryngeal nervesBlood supplySuperior half: superior laryngeal a. (branch of the s. Thyroid a.)Inferior half: inferoir laryngeal artery (branch of the i. Thyroid artery)Lymph drainage:Superior + inferior deep cervical nodes jugular trunk thoracic duct (L)/right thoracic duct (R)- Thyroid anatomy for those interested
18Thyroid Gland Innervation Parasympathetic fibers come from the vagus nervesSympathetic fibers are distributed from the superior, middle, and inferior ganglia of the sympathetic trunk.Blood supplySuperior half: superior thyroid arteryInferior half: inferior Thyroid arteryLymph drainage: periglandular nodes prelaryngeal pretracheal paratracheal mediastinal lymph nodes.Thyroid gland
25Waldeylers ringsWaldeyer's-Pirogov tonsillar ring describes the lymphatic tissue in the pharynx and to the posterior oral cavity.It containsPharyngeal tonsil (also known as 'adenoids' when infected)Tubal tonsil (where Eustachian tube opens in the nasopharynx)Palatine tonsils Lingual tonsils
27Cervical lymph node drainage Main lymph node groups in the neckSubmental/ SubmandibularParotidRetropharyngealAnterior cervicalDeep lateral cervical
28Submental/Submandibular 1. Submental nodesdrainage from: adjacent skin, lips, floor of the mouthdrain to: the submandibular nodal group2. Submandibular nodesdrainage from : anterior face, flow of the mouth, anterior oral cavity, and submental nodal group.drain to :the high internal jugular chain (7)
29Parotid 8. Parotid gland nodes Intra or extra glandular nodes. drainage from: external artery canal, eustachian tube, adjacent skin, buccal mucosa.drain to: high internal jugular chain (7)
30Retropharyngeal Two compartments: Medial and lateral retropharyngeal. Medial retropharyngealdrainage from: nasal pharynx and oral pharynxdrain to: high internal jugular chain.Lateral retropharyngeal: same as medialClinical sign: Early sign of nasal pharyngeal cancer may be presence of abnormal lateral retropharyngeal node in the patient over forty.
31Deep Lateral cervical Consists of Internal Jugular chain (7) drainage from: from parotid, retropharyngeal, and submandibular/submental groups.drain to: the subclavian vein and/or internal jugular vein and/or into the right lymphatic duct and thoracic duct.Posterior triangledrainage from: occipital/mastoid, lateral neck, scalp, nasal pharyngeal sources.drain to:Supraclavicular: Same as Post. Triangle
32Anterior cervicalAnterior jugular: superficial. Follows the course of the external jugular vein. Receives drainage from skin and muscles of the anterior neck. Drains to the thoracic duct.Paraesophageal group: Tracheal esophageal groove nodes and delphian node. Abnormal delphian node is often an indicator subglottic laryngeal cancer extension.This group receives drainages from hypopharynx, larynx, thyroid, and esophagus. Drainage is then to the thoracic duct.
33Physiology of the lymphoid system Re-uptake of excess fluid in interstitial tissue at capillary bedsAntigen presentation to naive lymphocytesActivation of naive lymphocytes