L1 Face Scalp (2).pdf

Face & scalp-blood supply and nerve supply Dr Srinivasa Rao Fall 09/09/18  Objectives Describe the innervation and blood supply of scalp and face Name and demonstrate the course of the main branches of th...

Face & scalp-blood supply and nerve supply Dr Srinivasa Rao Fall 09/09/18  Objectives Describe the innervation and blood supply of scalp and face Name and demonstrate the course of the main branches of the facial nerve on the face and describe the consequences of injury to it Describe the origin and course of the facial artery and course and termination of the facial vein Describe pattern of blood supply of head and neck region (ECA branches and venous drainage)  Scalp Extent Anteriorly: supra-orbital margins Posteriorly: external occipital protuberance & superior nuchal lines Each side: zygomatic arches Made up of five layers S – Skin C – Connective tissue (Dense) A – Aponeurotic layer or epicranial aponeurosis L – Loose areolar tissue P - Pericranium  Layers of the scalp Skin: – Thick & hairy – Contains sebaceous & sweat glands – Common site for sebaceous cysts Connective tissue: contains superficial nerves & vessels Aponeurosis- tendinous sheet that connects the frontal and occipital belies of occipito- frontalis muscle Loose connective tissue: Allows the first three layers to move as one unit Contains emissary veins Dangerous area of scalp Pericranium Outer periosteum that covers the outer surface of skull  Muscles of scalp Occipitofrontalis Embryologically derived from mesoderm of second pharyngeal arch Has frontal belly anteriorly and occipital belly posteriorly connected by aponeurotic tendon Action: moves scalp on skull and raises eyebrows Nerve supply Frontal belly - temporal branch of VII CN Occipital belly - posterior auricular branch of VII CN  Sensory nerve supply of scalp Scutarous In front of the ear From opthalmic Supratrochlear N. (CN V1)> I Supraorbital N. (CN V1) & & Zygomaticotemporal N. (CN & V2) Auriculotemporal N. (CN 8 V3) Behind the ear ↑ Great auricular N. (C2, C3) Lesser occipital N. (C2) Great occipital N. (C2) Third occipital N. (C3) Motor nerve supply of scalp Temporal branch & posterior auricular branch of facial nerve supply occipito-frontalis  Arterial supply of scalp In front of the ear – Supratrochlear artery (branch J Internal Caretid Artey of ICA) – Supraorbital artery (branch of ICA) – Superficial temporal artery (branch of ECA) Behind the ear – Posterior auricular artery (ECA) – Occipital artery (ECA) (oon) arteis I place only blu these Anastomosis b/w internal carotid artery and external carotid artery is found at scalp and medial corner of eye  Venous drainage of scalp Supratrochlear and supraorbital veins form angular vein Superficial temporal vein forms the retromandibular vein Posterior auricular vein forms external jugular vein Occipital vein terminates into sub-occipital ( Suboccipital venous plexus( venous plexus Emissary veins Connects extracranial veins with intracranial venous sinuses Parietal emissary vein- superior sagittal sinus > - angular Mastoid emissary vein- sigmoid sinus vein S ( Infections from scalp can spread to intracranial - venous sinuses through emissary veins -  Lymphatic drainage of scalp Parotid lymph nodes: anterior part of scalp Mastoid & occipital lymph nodes: posterior part of scalp Finally lymph from these nodes drain into deep cervical lymph Occipital nodes lymph nodes Parotid lymph nodes Mastoid lymph nodes  Clinical anatomy Sebaceous cysts Due to blockage of ducts of sebaceous glands & swollen hair follicles Sebaceous cysts Loose areolar tissue Dangerous layer of scalp Bleeding (accumulation of ) leads to BLACK EYE Forms a plane of separation in avulsion injuries of scalp  Deep wounds of scalp gape widely if aponeurosis is cut transversely, bleed profusely Pressure must be applied directly on wound to prevent bleeding Cephalhaematoma Collection of blood beneath the pericranium Swelling never extends beyond the edges of affected bone???? Caput succedaneum Temporary swollen and oedematous condition of scalp in new born Caused by pressure on the head during vaginal delivery???  Facial muscles Orbicularis oculi Eyelids Corrugator supercilii (Palpebral fissure) Levator palpebrae superioris Compressor naris Nose Procerus (Nostril) Dilator naris Depressor septi Auricularis anterior Auricle Auricularis superior Auricularis posterior  1. Orbicularis oris 2. Levator labii superioris alaequae nasi 3. Zygornaticus major 4. Levator labii superioris 5. Levator anguli oris Mouth 6. Zygomaticus minor (Oral fissure) 7. Depressor anguli oris 8. Depressor labii inferioris 9. Mentalis lO. Risorius 11. Buccinator ↑ Second Faraglid arch oh neuv  Functional groups of facial muscles Constrictors Dilators Palpebral fissure Orbicularis oculi Levator palpebrae superioris Occipitofrontalis (frontalis part) Oral fissure Orbicularis oris All the muscles around the mouth except orbicularis oris Nostril Compressor naris Procerus Dilator naris Depressor septi Muscles of face embryologically derived from mesoderm of second pharyngeal arch, supplied by VII CN except Levator palpebrae superioris, supplied by III CN  Actions of facial muscles Muscle Actions Corrugator supercillii Produces vertical wrinkles of forehead Orbicularis oculi Closes the lids tightly (orbital part) Closes the lids gently (palpebral part) Orbicularis oris Closes the mouth Prevents accumulation of food in the vestibule of mouth Buccinator Helps in sucking and blowing trumpet Whistling muscle Platysma Releases pressure of skin on subjacent veins, depress mandible  Orbicularis oculi Orbicularis oris Buccinator  Muscles producing facial expression Smiling and laughing: Zygomaticus major Sadness: Levator labii superioris and levator anguli oris Anger: Dilator naris and depressor septi Frowning: Corrugator supercilii and procerus Horror and fright: Platysma Surprise: Frontalis Doubt: Mentalis Grinning: Risorius Contempt: Zygomaticus minor  Arterial supply of face Face is supplied by facial artery and transverse facial artery Facial artery: Origin: branch of ECA, just above the level of tip of the greater cornua of the hyoid bone Course Enters face by winding around the base of mandible Presents tortuous course FA Pulsations can felt at anterior border of masseter Termination At the level of medial corner of eye Anastomose with the branch of ophthalmic artery (ICA)  Facial artery cont… Branches in neck Ascending palatine: soft palate, tonsil & pharynx Tonsillar: palatine tonsil Submental: submental triangle Submandibular branches Branches in face Inferior labial: to lower lip Superior labial: to upper lip and nasal septum Lateral nasal: ala and dorsum of the nose Angular artery: terminal branch Superior labial artery is part of Kiesselbach's plexus at Little’s area of epistaxis  Cont…. Transverse facial artery Branch of superficial temporal artery Runs between the parotid duct and zygomatic arch Transverse facial artery  Venous drainage of face Facial vein Begins as angular vein at the medial angle of the eye Joins with anterior division of & I retromandibular vein to form common facial vein 2 Common facial vein drains into Y 6 1 - internal jugular vein - No valves (graviley) = Deep connections Deep facial vein connects facial vein with pterygoid venous plexus Connection b/w supraorbital and superior ophthalmic veins Through these connections facial vein communicates with cavernous sinus  Venous drainage of face Retromandibular vein Formed by the union of the superficial temporal and maxillary veins Within gland divides into anterior and posterior divisions Anterior division forms the common facial vein Posterior division forms external jugular vein  Dangerous area/triangle of face Due to connections between the facial vein and cavernous sinus Infections upper lip & nose spread to cavernous sinus Can cause thrombophlebitis of cavernous sinus  Lymphatic drainage of face Parotid lymph nodes (a) Submandibular lymph nodes (b) Submental nodes (c) Lymph from these nodes finally drains into deep cervical lymph nodes ⑤ Neut  Nerve supply of the face Sensory Motor Trigeminal nerve Facial nerve + f N N  · Facial nerve Carries Fiber Seventh cranial nerve ↳ Mixed nerve with motor and sensory roots Emerges from the brain stem between the pons and the medulla - Controls muscles of facial expression Conveys taste sensations from anterior two thirds of the tongue motor Supplies preganglionic parasympathetic fibres to submandibular, sublingual and lacrimal glands  Facial nerve branches Emerges from skull at stylomastoid foramen Immediately gives: nerve to the posterior belly of digastric, nerve to stylohyoid and posterior auricular nerve (to occipitalis) Enters parotid gland and gives terminal branches Terminal branches Temporal: frontal belly of occipito-frontalis, corrugator supercilii, muscles of the auricle, orbicularis oculi Zygomatic: orbicularis oculi Buccal: muscles of upper lip, buccinator & orbicularis oris Marginal mandibular: muscles of lower lip and chin Cervical: platysma  Bell's palsy Injury to facial nerve or branches of facial nerve Causes Infections - Inflammation of facial nerve near stylomastoid foramen Fracture of temporal bone Tumors of face Symptoms: Loss of symmetry on the face Wrinkles disappear from forehead Inferior eyelid evert from surface of eyeball Any attempt to smile draws the mouth to normal side Cannot whistle or blow a wind instrument Palsy…..Right or left??? Weakened lip muscles affect speech Food accumulates between the teeth and the cheek  Sensory nerve supply of face - ↳ grea Ophthalmic nerve (V1) Maxillary nerve (V2) Mandibular nerve (V3) Supraorbital & Infraorbital Mental supratrochlear Zygomaticofacial Buccal nerve Zygomaticotemporal Auriculotemporal Lacrimal nerve Infratrochlear Fac Great auricular nerve (branch from cervical plexus): skin over nerve angle of jaw and parotid gland External nasal  Clinical anatomy a a). Infra-orbital nerve block – Injection is given at infra-orbital foramen b). Mental nerve block – Injection is given at mental foramen c). Buccal nerve block – Injection is given at retromolar fossa, behind b 3rd mandibular molar teeth c  Cont… Trigeminal neuralgia – Involve one or more divisions of trigeminal nerve – Sudden attacks of excruciating facial pain – lesions of the ganglion, demyelination of the nerves, narrowing of the foramina & Idiopathic – Treatment: Injection of 60 to 90% alcohol & peripheral nuerectomy Testing sensory function of CN V  Corneal/blink reflex Involuntary blinking of the eyelids elicited by stimulation of the cornea Afferent (sensory): ophthalmic division of V CN Efferent (motor): zygomatic branch of VII CN Conditions where corneal reflexes is absent????? Blood supply of head and neck region Common carotid artery External carotid artery Subclavian artery External jugular vein Internal jugular vein Anterior jugular vein  Common carotid artery Origin: Right CCA branch of brachiocephalic trunk, begins in neck Left CCA branch of aortic arch begins in thorax Course: Runs in carotid sheath along with IJV & vagus nerve Bifurcate into ECA & ICA at the upper border of thyroid cartilage CCA compressed against Stop prevent anterior/carotid tubercle of bleeding- transverse process of C6 vertebra CCA usually ligated at the upper part of neck where it is superficial  Carotid sinus Localised dilatation at terminal part of CCA/beginning of ICA Innervated by glossopharyngeal & sympathetic nerves thick portion of Act as baroreceptor tunica advetee Carotid sinus Carotid sinus hypersensitivity cause Carotid body excessive slowing of the heart rate & fall in blood pressure Carotid body Behind bifurcation of CCA Innervated by glossopharyngeal nerve, vagus & sympathetic nerves Acts as chemoreceptor  Carotid aneurysm Usually seen at the bifurcation of the CCA Aneurysm may create pressure on – Vagus nerve (causing hoarseness?) – Hypoglossal nerve (causing weakness of tongue) – Sympathetic trunk (causing Horner’s syndrome???)  External carotid artery ECA is terminal branch of CCA Begins in carotid triangle at level of upper border of thyroid cartilage Enters substance of parotid gland Termination- behind neck of mandible ECA Branches Ascending pharyngeal - Medial branch Superior thyroid Lingual Anterior branches Facial Occipital Posterior branches Posterior auricular Superficial temporal Maxillary Terminal branches  Subclavian artery Principal artery of the upper limb Also supplies part of the neck & brain Right subclavian artery from brachiocephalic trunk; left subclavian artery from arch of aorta Divided into three parts by scalenus anterior Branches 1st Part: Vertebral artery Thyrocervical trunk – Inferior thyroid artery Internal thoracic artery 2nd Part: Vertebral artery Costocervical trunk Inferior thyroid 3rd Part: artery Dorsal scapular artery  Subclavian artery Subclavian artery may be compressed by cervical rib Subclavian artery (third part) aneurysm may compress brachial plexus Cervical rib Scalenus anterior Subclavian artery  Head & Neck arterial pulsations Anaesthetist’s arteries???? Carotid pulse: anterior border of the sternocleidomastoid at the level of the superior border of thyroid cartilage Superficial temporal artery pulse: temporal artery- anterior to ear Facial artery pulse: anterior to the masseter muscle  External jugular vein Formation: posterior division of retromandibular vein and posterior auricular vein Lies deep to platysma Runs superficial to sternomastoid muscle Pierces the investing layer above the clavicle Investing layer is attached to wall of external jugular vein External jugular vein Sternomastoid Termination: subclavian vein  External jugular vein Used to measure venous pressure If vein is cut along posterior border of sternomastoid results in air embolism????? Used for catheterization – Catheter is inserted halfway between cricoid cartilage and clavicle – Right EJV commonly used, as its in direct line with the superior vena cava  Internal jugular vein Begins at jugular foramen Continuation of the sigmoid sinus Descends in carotid sheath Ends by joining with subclavian vein to form brachiocephalic vein Oblique jugular vein connects external and internal jugular veins Special features Superior bulb: dilation at is origin Inferior bulb: dilation near its termination 1 bicuspid valve above inferior bulb  Internal jugular vein Dilated and engorged in congestive heart failure In malignancies involving deep cervical nodes, vein is removed together with the nodes Used for catheterization – Catheter is inserted at apex of triangle formed by sternal and clavicular heads of the sternocleidomastoid  Anterior jugular vein Formed by union of the submental veins Runs close to the median line of neck Drain into the external jugular vein Two anterior jugular veins connected by jugular venous arch Anterior jugular vein Jugular venous arch thank you