Overview of the Neck Anatomy PDF

OVERVIEW AND SURFACE AND SECTIONAL ANATOMY OF THE NECK Head and Neck Anatomy II BDS-202 Dr. Jayaraj Ajman University 27-Aug-24...

OVERVIEW AND SURFACE AND SECTIONAL ANATOMY OF THE NECK Head and Neck Anatomy II BDS-202 Dr. Jayaraj Ajman University 27-Aug-24 1  LEARNING OUTCOMES  Discuss the surface and sectional anatomy of the neck  Describe the layers of deep cervical fascia, fascial spaces and their clinical significance  Describe the cutaneous supply and cervical plexus of neck and cervical plexus block Ajman University 27-Aug-24 2  Neck  Neck Is the area between the & - base of the skull - And= inferior border of the mandible - - And the - > superior thoracic aperture Is a tubular constriction -  Connects the& - => & of the head to the trunk - body I channel -  Serve as a conduit for structures passing - - - - to and from the head and the trunk -- - - & Ajman University 27-Aug-24 3  Regions of the Neck Strap muscles  Neck is divided into the&four regions Anterior region - Right lateral region - Left lateral region - Posterior region o - (nucha) -  Anterior region of the neck  Contains -Strap muscles Visceral structures -Pharynx, &&esophagus, larynx and& trachea Vessels to and from the head - - Four cranial nerves e &Thyroid and e parathyroid glands = Ajman University 27-Aug-24 4  Regions of the Neck  Structures can be palpated in the & anterior region - - Hyoid bone Thyroid cartilage I & - Cricoid cartilage & - Tracheal rings & - & Isthmus of the thyroid gland - z - - Thyroid lobe Y - & Suprasternal (jugular) notch - - & Common carotid artery -- Ajman University 27-Aug-24 5  Regions of the Neck lymph cervical - nodes  Right and Left E - - lateral regions of the neck  Composed of - Two large superficial muscles = - And -cervical lymph nodes  Structures can be palpated in the lateral region - - &Mastoid process &Clavicle - Sternocleidomastoid muscle - Trapezius -larg > - 2 superfacial muscles -External jugular vein - & & Transverse process of the atlas vertebra Ajman University 27-Aug-24 6  Regions of the Neck enucha  Posterior region of neck -  Includes Cervical vertebral column - - - & Spinal cord, and associated structures -  Structures can be palpated in the posterior & - region External occipital protuberance - &Superior nuchal line Spine of& - 7th cervical vertebra - & - Ajman University 27-Aug-24 7  Langer's Lines  Langer's lines (Tension lines or -  & - cleavage lines) T Topological lines drawn on a map of the - -- - human body - & 2 & - Correspond to the natural orientation of collagen fibers in the dermis & - Generally - - parallel to the orientation of the - - - underlying muscle fibers - & -Important for surgical operations Incisions made parallel to Langer's lines may - & - - & - heal better And produce & - - less scarring than those that - cut across - Ajman University 27-Aug-24 8  Skin in the Region of Neck - -  Skin Is the- & - superficial structure covering the neck - - Is # thin and normally under & - tension Direction of Langer’s lines often correspond with the - & - - - & -wrinkle lines Surgical incisions made along these lines & - - o Neck heal with invisible scars Ajman University 27-Aug-24 9  Fascia of the Neck  & Two main layers of cervical fascia  Superficial fascia 2  Deep fascia - subcutaneous layes > - thin [.  Superficial fascia 2) varying amount - of as =Thin layer of subcutaneous connective tissue - - = Lies between the dermis of the skin and the = deep cervical fascia Contains the& platysma, cutaneous nerves, &blood, and- lymphatic vessels Contains a - - varying amount of fat, which is its - distinguishing characteristic - - *L - Ajman University 27-Aug-24 10  superfacial Fascia of the Neck - facia  Platysma supplied by facial nerve > - ↳ depress mangible the Thin - & broad sheet of muscle Lies in the superficial fascia - - - Ascends onto the & & - face from the- I front of the neck - , C Extends from the pectoralis - & - - major and => deltoid muscle Attached to - - facial skin and mandible - Supplied by- facial nerve  Releases the pressure underlying veins and helps in - - - - - the venous return acedes  Helps to - & depress the mandible - H & Ajman University 27-Aug-24 11  of the following w hich associated with Hayed laye movement muscular Fascia of the Neck component Deep facia-of Investing layers  Deep fascia of the neck d Covers the muscles, viscera, and neurovascular - structures of the neck = &  Investing layer - - and - Surrounds sternocleidomastoid trapezius muscles & & - Forms an outer& musculofascial collar  Functions to rotate - --- & the head and flex the neck  Layer also creates a - - muscular compartment - & Contains a group of muscles - - & Associated with movements of the& hyoid bone - T & - Ajman University 27-Aug-24 12  & Fascia of the Neck  Superiorly:  Attachments of Investing Superior nuchal line - layer - - = Lower border of the &  Posteriorly: - mandible &Ligamentum nuchae - Mastoid process C7 cervical - spine. - = External occipital  Anteriorly: - protuberance - - Symphysis menti  Inferiorly: Hyoid bone - Manubrium -Fascia of opposite side - - Clavicle - Acromion process - Spine of scapula - Ajman University 27-Aug-24 13  attachment upward To the muscle Fascia of the Neck & midlines Hyoid book I in of stram Oblique ~ deepentranyoied compartment Glaterally - > void ing cartliage visceral V ob  Pretracheal fascia - ↳ form visional organs - ↳ , Blend inferiorly e evantisia a orta auch laterally carotied sheath Forms the visceral - > compartment by surrounding the ↳ Blend - - & -visceral organs in the neck Lies deep to the - - - infrahyoid strap muscles of the & - anterior triangle of the neck = =  Upward attachment -Hyoid bone at the midline - - - Oblique line of the thyroid - cartilage laterally  Splits to enclose the& - - thyroid gland  Blends inferiorly with the adventitia of the arch of the ---- - O - aorta  Blends laterally with& carotid sheath - Ajman University 27-Aug-24 14  sheath axillary Fascia of the Neck enclose Intrinsic muscles M -  Prevertebral fascia ↳ Vertebral compartment - Encloses the - - intrinsic muscles of the neck - To form the vertebral & = compartment T Surrounds the- - & vertebro-muscular block Extends from the& base of the skull downwards to the level : - & of T3 vertebra - Prolonged laterally towards the axilla as the axillary - - - - - sheath =  Provides a fixed basis · ji1g Pharynx, esophagus, and& & - - neck movements carotid sheaths can glide during - And swallowing - undisturbed by movements of the - - prevertebral muscles - Ajman University 27-Aug-24 15  Fascia of the Neck enervestresses compartment  Carotid sheath nuvovascular of  Surround the- nerves and vessels of the basia Notochaa - => neurovascular compartment > - - v blood +  Formed by a combination of - & - connective tissue - That originates from the= & - & blood vessels and -investing and- - pretracheal fascia  Contains Internal jugular vein - Common or internal carotid arteries - - - & Vagus nerve - &Sympathetic trunk is located behind the - - - - carotid sheath & Ajman University 27-Aug-24 16  layes Compartment of the Neck ⑳ Ling guesDeep Facial rotation - ↳ Involved on  Musculofascial collar of the head Include muscles and the investing fascia ↳ musculo facial ~ of th - - - Involved in the - rotation of the head tation nock 50 compartment ↳ vertebral -  Muscular compartment -envesting layer - - - Contains muscles that regulate & hyoid bone while swallowing and speaking & - -  Visceral compartment protracheal > - Contains pharynx, larynx, esophagus, trachea, and thyroid and parathyroid glands F - - - &  Neurovascular compartment carobied sheath > - Contains the major arteries -O- and veins, lymphatic vessels and nerves - &  Vertebral compartment prevertebra > - Contains vertebrae and the intrinsic muscles of the neck -- & Involved in&flexion, extension, and-rotation of the neck Ajman University 27-Aug-24 17  Fascial Spaces and the Spread of Infection I - & enfection Odontogenic  Fascial spaces >- - -  Prevent structures from sticking to each & other & and  Allow movement of organs (trachea - &esophagus)  Clinically important - Facilitate the spread of infection - & Fascial spaces of the - floor of the mouth to * - & - the spaces of the neck - * - Fascial spaces allows odontogenic infections & & & to spread into the& - & mediastinum Ajman University 27-Aug-24 18  Sublingual Region > - Parapharyngeal Space - - ↳, related to lymph nodes to the pharynx postro-latera  Parapharyngeal space - - - & to the& Lies immediately postero-lateral - pharynx T Extends forward into the sublingual - - - & region So that together form a ring -- - = & about the pharynx  Intervene between The interfascial spaces and the mandible -- - - one hand - & And the pharynx on the other & & -  Intimately related to the& - - lymph nodes Receive drainage from the ⑤ - - nose, throat and - O jaw Ajman University 27-Aug-24 19  Parapharyngeal Space  Clinical Significance => - Infections from the floor - of the mouth can gain access to the pharyngeal space - I  Receive infection from & Teeth - Submandibular gland - Masticator space Parotid space & Paratonsillar space  From parapharyngeal space infection pass to = - - & retrophargyngeal space  Then to superior - - mediastinum Ajman University 27-Aug-24 20  C Retropharyngeal Space -  Retropharyngeal space Located between the - & - vertebral column and the visceral compartment of the neck & & - & Lying behind the- & - In front of the- pharynx prevertebral fascia & Extends from the- 2 & base of the skull to the diaphragm &  Boundaries Anteriorly - Posterior wall of pharynx = - Posteriorly - Pre vertebral fascia - Superiorly - Base of skull -  Space allows- the expansion of - - Inferiorly - Superior mediastinum - the pharynx during& - swallowing - Ajman University 27-Aug-24 21  Retropharyngeal Space the for Infection from  Clinical Significance > rout - a mouth Auroak - L - & - & and& Act as a route for infection from the mouth throat And infection pass to- - - & superior mediastinum  Source of infection from mouth - & & to- & retropharyngeal space & First molar are the commonest source of infection ---- - - Third molar are the second important source of & - - - infection & enclosed  Retropharyngeal abscess --- - Due to involvement of retropharyngeal lymph nodes Produces paramedian unilateral bulge in the posterior --- - pharyngeal wall - - and - Cause difficulty in swallowing breathing b Desphaia & & dyspnea Ajman University 27-Aug-24 22  Ludwig’s Angina  Ludwig’s angina - Bilateral swelling of the submental, sublingual, and submandibular spaces - - - Commonly formed by theE - & - abscess of the apices of the teeth Pus penetrates the lingual plates of the - -- mandibular teeth And gains access to submental, sublingual, and submandibular spaces - & & - -Patient presents with Extreme hardness to the- - floor of the mouth and -dysphagia Tongue is elevated and can be pushed to one side - -  Infection then spread into the- & & lateral pharyngeal space And cause an - - M indurated swelling of the neck  Infection can advance into the mediastinum - - -  The infection requires careful monitoring and- - - - rapid intervention for prevention - of-asphyxia and- aspiration pneumonia g =X, C 24! Ajman 3-Sep-24 8.e + 11 % University 23  Cutaneous Innervation of the Neck cutaneous 39 - >( - - no  Cutaneous innervation Supply the - - - skin of the neck, upper thorax, D & - scalp and ear > -- C2, C3, and & Is derived from && C4 spinal segments - -C1 nerve has no cutaneous branch  Nerve point of the neck (Erb’s point) Nerves all enter the skin at the - - - - middle of the posterior border of the sternocleidomastoid - - -ventral Jami  Skin on the - anterolateral aspect of the neck Supplied by- - ventral rami of&& C2, C3, and&C4 spinal nerves = vari dorsal  Skin on the- > - posterior aspect of the neck -> Supplied by dorsal rami of 888- C2, C3, C4 and C5 spinal & nerves & Ajman University 27-Aug-24 24  Cutaneous Nerves of the Neck &and side  Skin on the front &of the neck - - & Each side is supplied by four &cutaneous nerves Derived from ventral rami of 06 - - C2, C3, &spinal nerves - and C4 nock middle Oupper posteriorly  Lesser occipital nerve (C2) Supplies to the - - & posterosuperior scalp Posterior part of auricle - - - Upper middle neck posteriorly - - & -  Great auricular nerve (C2 and C3) - F Supplies skin over & - - - auricle, parotid and = - angle of mandible Ajman University 27-Aug-24 25  Cutaneous Nerves of the Neck middle nock -upper anteriorly  Transverse cervical nerve (C2 and C3) - - Curves around the - -- posterior aspect of the sternocleidomastoid - Supplies to the anterior and lateral neck - - - Upper middle neck anteriorly - -  Supraclavicular nerves (C3 and C4) - & Arise from posterior border of - - - sternocleidomastoid - Supplies to skin overlying the - & - suprascapular fossa Upper - & thoracic region and sternoclavicular joint & & parts of neck Medial and lateral - Ajman University 27-Aug-24 26  Cutaneous Nerves of the Neck  Skin on the back of the neck - & - - C2, C3, C4 and0 Is supplied by dorsal rami of000 C5 spinal nerves & thickest neve > -  Greater occipital nerve (C2) Supply the- - >posterior part of the scalp -Thickest cutaneous nerve in the body - &  Third occipital nerve = (C3) 199 Supplies the - -- nape of the neck up to the - > & external occipital protuberance -  Cutaneous branches of C4 and C5 - -Supply the adjacent skin Ajman University 27-Aug-24 27  Cervical Plexus  Cervical plexus Network of & nerve fibres - Supplies innervation to structures in the - - = - neck and & trunk Located in the& & posterior triangle of the neck - - & Located halfway up the - - - sternocleidomastoid muscle And within the - - prevertebral layer Formed by the- & & anterior rami of cervical spinal - nerves D & C1-C4 &  Divided into S-3 > - - - -  Superficial (mainly sensory): Supply skin of neck  Deep (mainly & & motor): Supply& muscles of neck Ajman University 27-Aug-24 28  Cervical Plexus sensory -  Superficial Branches Formed by= - the anterior rami of cervical spinal nerves C1-C4 - -  Lesser occipital nerve (C2)  Great auricular nerve (C2 and C3) -  Transverse cervical nerve (C2 and C3)-  Supraclavicular nerves (C3 and C4) - Ajman University 27-Aug-24 29  Cervical Plexus Motor -  Deep Branches  Communicating branch (C1) - - - Merge with Hypoglossal nerve - > Supplies -thyrohyoid and geniohyoid muscle  Ansa cervicalis  Loop formed by - -Superior root (descendens hypoglossi)(C1) - - T -Inferior root (descendens cervicalis)(C2-C3) - - -  Supplies infrahyoid muscles Omohyoid - Sternohyoid - & Sternothyroid - Ajman University 27-Aug-24 30  Cervical Plexus -  Phrenic nerve (C3-C5) -  Provide motor -- & innervation to the& -diaphragm Provide ⑤ - sensory innervation to - &diaphragmatic pleura, pericardium  Proprioceptive branches - Branch from C2–C3 to sternocleidomastoid & - - Branches from C3–C4 to trapezius - - Communicate with spinal accessory nerve -- - Ajman University 27-Aug-24 31  Cervical Plexus  Muscular branches To prevertebral muscles Rectus capitis anterior (C1) Rectus capitis lateralis (C1, C2) Longus capitis (C1–C3) Longus colli (C2–C4) Strap muscles (C1–C3) Sternocleidomastoid (C2) Trapezius (C3, C4) Levator scapulae (C3, C4) Scalene muscles (C3, C4) Diaphragm (C3, C4) Ajman University 27-Aug-24 32  Cervical Plexus Block  Deep and superficial cervical plexus blocks - Needle insertion during - - - Used in a variety of surgical procedures, including superficial - & deep cervical blockade surgery on the& - & and - neck and shoulders thyroid surgery Block is done by giving anesthetic at the midpoint -- & - e on the & posterior - border of sternocleidomastoid - & muscle (Erb’s E point) -Superficial cervical blocks anesthetizes ---- Skin of anterolateral neck, anterior and retroauricular areas eDeep cervical block anesthetizes AMuscles of the neck,- geniohyoid, prevertebral muscles  Blockade of the phrenic nerve Anesthetic agents - Sternocleidomastoid, levator scapulae, the scalenes, & Bupivacaine -- - trapezius, and the diaphragm Ropivacaine & - & Ajman University Mepivacaine 3-Sep-24 33  Cervical Plexus Block  Because the phrenic nerve supplying the - - diaphragm, pericardium is also paralyzed by cervical plexus block, this procedure is not performed on- - patients with pulmonary or = - cardiac disease  A phrenic nerve block - - produces a short period of paralysis of the diaphragm on one side (e.g., - & for a lung operation). - -  A surgical phrenic nerve crush (e.g., -- compressing the nerve injuriously with forceps) - & - # produces a= longer period of paralysis Ajman University 3-Sep-24 34  Cervical Sympathetic Trunk -  Cervical sympathetic trunk -One on either side of cervical part of the vertebral - - column - Lies behind the carotid sheaths and in front of - - prevertebral fascia -  Superior cervical ganglion & - Form plexus around & - & internal and& external carotid arteries &  Middle cervical ganglion & - 2 - - Form a plexus around the inferior thyroid artery  Inferior cervical ganglion & - - - F - Form plexus around vertebral and subclavian arteries Ajman University 27-Aug-24 34  Horner’s Syndrome  Horner syndrome Elben 8 Results from an& & interruption of the sympathetic trunk & - Usually in the - & upper thoracic or-lower cervical region 24t 42  Characterized by the e Miosis (Constricted pupil) & & & Ptosis (drooping of the upper eyelid) - - - Anhidrosis (absence of sweating of the face) - - = Enophthalmos (sinking of the eyeball into the bony cavity) - & = P A E M b no D b drooping sinking Constricted upper eyelid Sweating pupil of the face Ajman University 27-Aug-24 35  Ajman University 27-Aug-24 36