1 / 56

Skin innervation of the face

Skin innervation of the face. Skin of the face is supplied by branches of trigeminal nerve except the area over the angle of mandible & parotid gland, which is supplied by great auricular nerve.. Ophthalmic nerve supplies the region developed from the frontonasal process.

lamont
Download Presentation

Skin innervation of the face

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Skin innervation of the face • Skin of the face is supplied by branches of trigeminal nerve except the area over the angle of mandible &parotid gland, which is supplied by great auricular nerve.. • Ophthalmic nerve supplies the region developed from the frontonasal process. • The maxillary nerve supplies the region developed from the maxillaryprocess of 1st pharyngeal arch. • The mandibular nerve supplies the region developed from the mandibular process of 1st pharyngeal arch. • Skin of face has numerous sweat & sebaceous glands. It is connected to underlying bones by loose C.T, in which are embedded the muscles of facial expression. • No deep fascia is present in the face.

  2. Ophthalmic Nerve • It supplies skin of forehead, upper eyelid, conjunctiva, & side of thenose, it has 5 branches : 1-Lacrimal N. : supplies skin & conjunctiva of lateral part of upper eyelid. 2-Supraorbital N.: winds at supraorbital notch,it supplies skin & conjunctiva on the central part of upper eyelid + skin offorehead. 3-Supratrochlear N. : it lies medial to supraorbital N. it supplies skin & conjunctiva on medial part of upper eyelid + skin of forehead. 4-Infratrochlear N. : leaves orbit to supply skin & conjunctiva on the medialpart of upper eyelid + skin of adjoining part of the side of the nose. 5-External nasal N. : leaves nose to supply skin on the side of the nose down as far as the tip.

  3. Maxillary Nerve • It supplies the skin of posterior part of the side of nose, lower eyelid, cheek,upper lip, lateral side of the orbit.It has 3 branches : 1-Infraorbital N. : is a direct continuation of maxillary N. it leveas orbit via infraorbital foramen. It gives numerous small branches to supply skin of lower eyelid & cheek, side of nose, &the upper lip. 2-Zygomaticofacial N. : passes onto face via a small foramen on lateral side of zygomatic bone to supply skin over thecheek. 3-Zygomaticotemporal N. : passes through a small foramen on the posterior part of zygomatic bone to supply skin oftemple.

  4. Mandibular Nerve • It supplies skin of lower lip,lower partof face, temporal region & part of theauricle + side of scalp. It has 3 branches 1-Mental N. : emerges from the mental foramen of mandible to supply skin oflower lip & chin. 2-Buccal N. : enters the face from under cover of the masseter. It passes over the buccinator. It supplies skin &m.m of cheek. 3-Auriculotemporal N. : leaves upper border of parotid gland , between superficial temporal vessels & auricle to supply skin of auricle,external auditorymeatus, outer surface of tympanicmembrane & skin of scalp above auricle.

  5. Arterial Supply of the Face • Facial artery : arises from external carotid artery. -it reaches face by piercing deep fascia atthe lower border of the mandible and then curving up to the face close to anteroiorborder of masseter, here its pulse can be easily felt. -it then passes upwards in a tortuouscourse over the mandible and buccinator towards the angle of mouth. -it then ascends along side of nose to the medial angle of eye, where it anastomoses with the terminal branches of the ophthalmic artery. • Superficial temporal artery : the smaller terminal branch of external carotidartery within the parotid gland.It ascends in front of auricle to supply the scalp.

  6. Arterial Supply of the Face • Transverse facial artery : a branch of superficial temporal artery of external carotid artery, within the parotid gland.It runs forward across the cheek just above parotidduct. • Infraorbital artery : it is the terminal part ofmaxillary artery (one of terminal branches of external carotisd artery), it enters face via infraorbital foramen. • Mental artery : branch of inferior alveolar from maxillary from ext.c.artery, ,it enters face via mental foramen of mandible. • Zygomaticofacial & zygomaticotemporal arteries, from superficial temporal artery. • Lacrimal artery : from ophthalmic artery, of internal carotid artery. • Supraorbital & Supratrochlear arteries : branches of ophthalmic artery, of internal carotid artery , supply skin of forehead.

  7. Branches of Facial artery 1- Submental artery : arises at the lower border of the body of mandible to supply skin of chin + lowe lip. 2- Inferior labial artery : arises near angle of mouth to run medially in the lower lip and anastomoses with its fellow of opposite side. 3- Superior labial artery : runs medially in the upper lip and gives branches to the septum + ala of nose. 4- Lateral nasal artery : supplies skin on the side & dorsum of nose.

  8. Venous Drainage of Face • Facial vein : -is formed at the medial angle of eye by union of supraorbital &supratrochlear veins.-it is connected to cavernous sinus through superior ophthalmic vein.This connection is of greatclinical importance because it provides a pathway for spread of infection from face to cavernous sinus. -It descends behind the facial artery to the lower border of body of mandible. -It crosses with the facial artery superficial to submandibular gland. –It is joined by anterior division of retromandibular vein to form common facial vein to end into the internal jugular vein.

  9. Tributaries of Facial vein • It recevies tributaries that correspond to the branches of facial artery. • It is joined to pterygoid venous plexus ( a venous network lying around pterygoid muscles) by deep facial vein and to the cavernous sinus by superior ophthalmic vein. • Transverse facial vein joins superficial temporal vein within the parotid gland.

  10. Lymph Drainage of the Face • Lymph from forehead + anterior part of face drains into submandibularL.Ns., a few buccal lymph nodes may be present along course of these lymph vessels. • Lateral part of face + lateral parts of eyelids drin into parotid L.Ns. • Lower lip + chin are drained into submental L.Ns.

  11. Facial Nerve • It emerges from stylomastoid foramen to enter the parotid gland , it supplies all muscles of facialexpression. it does not supply the skin ,It runs within substance of parotid gland, it divides into 5 terminal branches :1- Temporal branch : emerges from upper border of gland to supply anterior + superior auricular muscles, frontal belly ofoccipitofrontalis, orbicularis oculi and corrugator supercillii. 2- Zygomatic branch : emerges from anterior border of parotid gland to supply orbicularis oculi.

  12. Facial Nerve 3- Buccal branch : emerges from anterior border of parotid gland below parotid duct to supply buccinator +ms.of upper lip & nostril. 4- Mandibular branch : emerges from anterior border of parotid gland to supply ms. of lower lip.5- Cervical branch : emerges from lower border of parotid gland , it descends in the neck to supply platysma muscle + depressor angulioris muscle.

  13. Skin & Fascia of the Face • Skin of face has numerous sweat &sebaceous glands. • It is connected to the underlying bones by loose connective tissue (superficial fascia), in which are embedded muscles of facial expression. • No deep fascia in the face.

  14. Muscles of Face (muscles of facial expression) • They are called ms. Ofexpression because they pull skin of face to produce various expressions. • They are arranged in groups around the eye, nose & mouth. • They havebony origin. • They are inserted intoskin of face (no deep fascia in face). • They are supplied by branches of facial N.,Except levator P.S. byocculomotor N. (striated ms.) + sympathetic N. (smooth ms.).

  15. Muscles of Face A) Muscles of eyelids : 1- levator palpebrae superioris (the dilator ms. of eyelids, lying in the orbital cavity). 2-Orbicularis oculi (the sphincter ms of eyelids). 3-Corrugator supercilii (deep to orbicularis oculi). 4-Occipitofrontalis (ms. ofscalp). B) Muscles of Nose : 1-Procerus. 2-Compressor & dilator naris.

  16. Muscles of Face • C) Muscles of Lips : • Sphincter muscle of the lips : “ Orbicularis Oris”. • Dilator muscles of the lips : 1-Levator labii superioris alaeque nasi. 2-Levator labii superioris. 3-Depressor labii inferioris. 4-Zygomaticus minor. 5-Zygomaticus major. 6-Levator anguli Oris (deep to zygomatic ms.). 7-Depressor anguli Oris. 8-Risorius. 9-Mentalis. D) Muscles of Cheek : “Buccinator”

  17. Muscles of Face (muscles of facial expression) • 3 large muscles : 1- Buccinator m. (ms. of cheek). 2- Orbicularis oculi m. 3- Orbicularis oris m. • Many small muscles :1- Dilator ms. of lips (separate lips) : -Levator labii superioris alaeque nasi, levator labii superioris. -Zygomaticus minor & major. -Levator anguli oris, risorius & depressor anguli oris. -Depressor labii inferioris & mentalis. origin : bones & fascia around oral aperature. Insertion : into substance of lips.

  18. 2- Corrugator supercilli :-It lies deep to orbicularis oculi.origin : superciliary arch (bone). Insertion : skin of eyebrow. Action : vertical wrinkles of forehead, as in frowning.3- Compressor naris & dilator naris : origin : maxilla. Insertion : the fibres are continuous with those of opposite side in front of the bridge of nose to form aponeurosis of bridge of nose.Action : compesses & widensnasal cartilages and aperature.4- Procerus : - It is continuouswith the medial part of occipito-frontalis ms. Origin : nasal bone. Insertion : medial part of skin of eyebrow. Action : wrinkles skin of nose.

  19. Orbicularis oculi :1- Orbital part :Origin : medial palpebral ligament + adjoining bone. Insertion :The fibres have no lateral attachment, it loops return to origin. Action : closes eyelids by throwing skin around orbit into folds to protect eyeball. 2- Palpebral part :Origin : medial palpebral ligament. Insertion : lateral palpebral raphe & skin of eyelids. Action : closes palpebral fissure of eyelids gently (sleep) and dilates lacrimal sac.

  20. Orbicularis oris :Origin : maxilla, mandible & deep skin. Insertion : encircles oral orifice to be inserted to the m.m lining the inner surface of lips. Action : compresses the lips together to close the mouth (sphincter muscle of lips).

  21. Muscle of Cheek : Buccinator Muscle : • Origin : from outer surface of maxilla & mandible opposite the molar teeth + from pterygomandibular ligament. • Insertion :1-upper fibres : into upper lip. 2-lower fibres : into lower lip. 3-middle fibres : decussate at the angle of mouth. • N.supply : buccal branch of facial N. • Action : 1- it compresses the cheeks & lips against the teeth to prevent accumulation of food in vestibule of mouth. 2- it is used in wistling, when cheeks are distended with air.

  22. Muscle of Cheek : Buccinator Muscle : • It is covered on outside by buccopharyngeal fascia & buccal pad of fat. • Its deep surface is lined by buccal mucosa. • It is pierced by :1-parotid duct , opposite upper 2nd molar tooth. 2-Buccal branch of mandibular nerve (sensory) to supply m.m of cheek on the inner surface of buccinator muscle.

  23. Facial muscle Paralysis • The facial ms. Are innervated by facial N. • Cause :Damage to facial N. (by a tumor in internal acoustic meatus or parotid galnd) /or operation or infection in middle ear / or perineuritis, Bell’s palsy in facial nerve canal. • Results :Lower motor neuron lesion which involves distortion of face+ drooping of lower eyelid + angle of mouth will sag on the affected side. /But Upper motorneuron lesion is due to lesion of pyramidal tract and here the upper face is normal because the neurons supplying this part receive corticobulbar fibres from both cerebral cortices.

  24. The Cranial Cavity • Contents of cranial cavity 1- the brain. 2-meninges of brain (dura, arachnoid & pia mater) from outside inwards. 3-blood vessels of brain & meninges. 4-parts of cranial nerves. 5-Blood venous sinuses. 6- Hypophysis cerebri (pituitary gland).

  25. Dura Mater of Brain • It is a thick dense membrane which consists of 2 layers (outer & inner). • The 2 layers are attached together except at blood venous sinuses. • Outer endosteal layer : -it covers inner surface of bones of skull. -it is firmily attached to sutures of skull and to foramen magnum, it does not extend through foramen magnum . • Inner meningeal layer : -it covers brain and continuous with duramater of spinal cord through foramen magnum. -it sends tubular sheaths around cranial nerves as they pass through foramina in skull. -it sends 4 septa into cranial cavity to divide cavity into spaces, these septa stabilize the brain within the cavity during movement of head.

  26. Dural Septa : 1- Falx Cerebri • It is a sickle-shaped fold of dura that descends in the midlinebetween 2 cerebral hemispheres. • Attachment : -its narrow anterior end is attached to internal frontal crest & crista galli. -its wide posterior end is attached to upper surface of tentorium cerebelli. -venous sinuses in falx cerebri :1- superior sagittal sinus : lies in its upper convex fixed border. 2- inferior sagittal sinus : lies in its lower concave free margin. 3- straight sinus : lies at line of attachment of posterior end of falax with tentorium cerebelli.

  27. 2- Tentorium cerebelli • It is a crescentic fold of dura that roofs posterior cranial fossa. • It separates the occipital lobe of cerebrum above from cerebellum below. • Its free border : -is concave and forms a gap called, tentorial notch, for passage of midbrain –it crosses above the attached border of tentorium to be fixed at the 2 anteriorclinoid processes.-at the point of crossing of the free & attached borders : the trochlear & oculomotor Ns. Pierce the tentorium to enter lateral wall of cavernus sinus. -at the apex of petrous temporal bone : the inferior layer of tentorium is invaginated anteriorly beneath the sup. Petrosal sinus to form a recess called trigeminal cave which contains the trigeminal ganglion.

  28. 2- Tentorium cerebelli • Attached border : -it is convex and directed peripherally. -its posterior part is attached to the lips oftransverse sulcus.-its anterolateral part is attached to the lips of groove for superior petrosal sinus (at the upper border of petrous temporal bone). -Its anterior end crosses below the free border and is attached to the 2 posteriorclinoid processes. • In the median plane :-the superior layer of tentorium cerebelli is attached to falx cerebri. -the inferior layer of tentorium cerebelli is attached to falx cerebelli.

  29. 2- Tentorium cerebelli • Venous sinuses in thetentorium cerebelli : 1-straight sinus : at the line ofattachment of posterior end of falx cerebri with tentorium cerebelli. 2-transverse sinus : in the posterior part of the attached border.3-superior petrosal sinus : in the anterolateral part of attached border.

  30. 3-Falx Cerebelli : • It is a small sickle-shaped fold of dura placed in median plane below tentorium cerebelli. • Its free anterior border projects forwards between the 2 cerebellar hemispheres. • Its posterior border is attached to the internal occipital crest. • It contains the occipital sinus in its posterior fixed border.

  31. 4-diaphragma sellae : • It is a small circular fold of dura. • It forms the roof of sella turcica. • It has a centeral opening for passage of the stalk of hypophysis cerebri (pituitary stalk).

  32. Dural Nerve Supply • Trigeminal N. • Vagus N. • First 3 cervical nerves. • Sympathetic fibres around the meningeal arteries.

  33. Dural Arterial Supply • Internal carotid artery. • Maxillary artery…. Middle meningeal artery, it is the most important branch. • Ascending pharyngeal artery. • Occipital artery. • Vertebral artery. Meningeal Veins • Middle meningeal vein follows the branches of middle meningeal artery and drains into the pterygoid venous plexus or sphenoparietal sinus.

  34. Middle meningeal artery • It is a branch of 1st part of maxillaryartery. • It reaches middle cranial fossa through foramen spinosum to lie between the meningeal & endosteal layers of dura. • It passes forwards and laterally grooving the squamous part of temporal bone. Then it divides into : 1-large anterior (frontal) branch. & 2-small posterior (parietal) branch. • It divides into anterior & posteriorbranches opposite a point 20mm above center of zygomatic arch.

  35. Extradural hemorrhage • This is intracranial hemorrhage outside the dura mater. • It results mostly from injury of middlemeningeal artery, usually occuring in the region of the pterion (at anteroinferior part of the parietal bone) as a result of a blow over the side of the head. • A collection of blood, (extraduralhematoma) occurs between the dura and the skull bones, stripping off the periosteum of inner table of the bone. • The intracranial pressure rises producing local pressure on the motor area of brain. • Blood may pass out through the fracture to form a soft swelling under the temporalis ms

  36. Arachnoid mater • It is a delicate, impermeablemembrane covering the brain, lying between pia mater & dura mater. • It is separated from the dura by subdural space, and from the pia by subarachnoid space, which is filled with cerebro-spinal fluid. • The arachnoid projects into the venous sinuses to form arachnoidvilli, they are most numerous atsuperior sagittal sinus, aggregations of arachnoid villi are called arachnoid granulations, where C.S.F diffuses into bloodstream. • Cerebral arteries &veins & cranial nerves lie in subarachnoid space.

  37. Cerebrospinal fluid • It is produced by the choroid plexuses within lateral, 3rd & 4thventricles of brain. • It passes via 3 foramina in roof of 4th ventricle to circulate in subarachnoid space, upward over surfaces of cerebral hemispheres and downward around spinal cord. • The spinal subarachnoid space extends down as far as 2nd sacralvertebra. • The fluid enters bloodstream by passing into arachnoid villi and diffuses into venous sinuses.

  38. Pia mater • It is a thin vascular membrane that closely covering the brain. • It extends over the cranial nerves and fuses with their epineurium. • The cerebral arteries enter the brain carrying a sheath of pia mater.

  39. Venous Sinuses • They are blood channels between the endosteal & meningeal layers of dura mater. • The walls of sinuses are lined by endothelium. • They receive tributaries from : the brain, the diploe of skull, the orbit, & the internal ear. • They differ from the veins in having no valves, or muscles in their walls. So they do not contract when they are ruptured and bleeding is controlled only by pressure. • Single sinuses are : 1-superior sagittal, 2-inferior sagittal, 3-straight sinus & 4-intercavernus sinus. 5-Occipital sinus. • Paired sinuses are : 1-transverse sinuses. 2-sigmoid sinuses. 3-cavernus sinuses. 4-superior & inferior petrosal sinuses. 5-sphenoparietal sinuses.

  40. Superior Sagittal Sinus • It lies in the upper fixed border of falx cerebri. • It begins in front at frontal crest & foramen cecum, where it receives : vein from nasal cavity, then runs backward grooving vault of skull. • At the internal occipital protuberance, it is dilated to form the confluence ofthe sinuses, here it deviates to one side (usually the right) to become the right transverse sinus. • It is connected to the opposite transverse sinus and it receives the occipital sinus.

  41. Tributaries and communications of the Superior Sagittal Sinus • The sinus communicates with 2-3 venous lacunae on each side. • Numerous arachnoid villi & granulations project into the lacunae, which also receive the diploic & meningeal veins. • It receives also the cerebral veins. • It communicates with veins of scalp by emissary veins passing through the parietal foramina.

  42. Inferior Sagittal Sinus • It lies in the free lower border of falx cerebri. • It runs backward to join great cerebral vein at free border of tentorium cerebelli to form straight sinus. • Straight Sinus • It lies at the junction of falx cerebriwith tentorium cerebelli. • It is formed by union of inferiorsagittal sinus & great cerebral vein. • It ends by turning to left to form theleft transverse sinus.

  43. Transverse Sinuses • Are paired sinuses, begin at the internal occipital protuberance. • Right sinus is usually continuous with the superior sagittal sinus, and left sinus is continuous with the straight sinus. • Each sinus occupiesthe attachedmargin of tentorium cerebelli, grooving the occipital bone. • They receive the superior petrosal sinuses, cerebral & cerebellar veins, & diploic veins. • They end by turning downward as sigmoid sinuses.

  44. Sigmoid Sinuses • Are direct continuation of transversesinuses. • Each sinus turns downward and medially and grooves the mastoid partof temporal bone, here it lies behind mastoid antrum. • Finally, it passes through jugular foramen to join the internal jugular vein.

  45. Occipital sinus • It is a small sinus occupying the attached border of falax cerebelli. • It begins near foramen magnum, where it communicates with vertebral veins and drains into the confluence of the sinuses. • It connects the beginning of transverse sinus with the end of sigmoid sinus. • May be single or paired.

  46. Cavernus sinuses • Are lie in middle cranial fossa on each side of body of sphenoid bone ( hypophyseal fossa). • Each sinus extends from superior orbital fissure anteriorly, to apex ofpetrous temporal bone posteriorly. • Inside the sinus : 1- internal carotid artery surrounded by sympathetic plexus. 2- abducent nerve. • In the lateral wall of cavernus sinus :1-oculomotor nerve.2-trochlear nerve.3-ophthalmic nerve of trigeminal N. 4-maxillary nerve of trigeminal N.

  47. Cavernus sinuses • Tributaries : 1-superior & inferior ophthalmic veins. 2-cerebral veins. 3- sphenoparietal sinus, along posterior margin of lesser wing of sphenoid. 4-central vein of retina. • Each sinus drainsposteriorly into: superior & inferior petrosal sinuses and inferiorly into :pterygoid venousplexus. • The 2 sinuses communicate with each other by anterior & posteriorintercavernous sinuses, which run in diaphragma sellae. • Each sinus has important communication with facial vein through superior ophthalmic vein.

More Related