Lec 5 Anatomy Notes - MSS - PDF

5 Hala shmari / Ahmad afaneh ILOs  Describe the extension, structure, muscles, blood and nerve supply, and lymph drainage of the scalp.  Describe the muscles of facial expression; motor and sensory nerve supply; blood supply and lymph drainage of the face....

5 Hala shmari / Ahmad afaneh ILOs  Describe the extension, structure, muscles, blood and nerve supply, and lymph drainage of the scalp.  Describe the muscles of facial expression; motor and sensory nerve supply; blood supply and lymph drainage of the face. 2  Scalp ‫فروة الرأس‬ The cranial vault, also known as the skull vault, skullcap or calvaria, is the cranial space that encases and protects the brain together with the base of the skull The scalp is a multilayered structure that cover the bones of cranial vault. is attach Extends from the superciliary arches anteriorly to to the external occipital protuberance & superior frontalis and nuchal lines posteriorly and superior temporal lines occipitalis laterally. Layers of the scalp can be defined by the word itself: From superficial to deep The scalp have five layers S—Skin. C—Connective tissue (dense). A—Aponeurotic layer. Flat tendon of the muscle L—Loose connective tissue. P—Pericranium (Periosteum). It’s inner layer and it direct contact with bone of the skull aponeurotic : is an intermediate tendon between occipital and frontal bellies of the occipitofrontalis muscle 3 Layers of the Scalp The superficial three layers (scalp proper) are tightly bound together and move as a one unit. ‫ عددها كبير مقارنه بأماكن أخرى بالجسم‬hair follicles ‫ال‬ Skin: Contains numerous hair follicles and sebaceous glands. ‫ عددها كبير‬sebaceous gland ‫ )نه ال‬sebaceous cyst ‫ممكن يصير‬ Because it dense that connect the skin first layer to Epicranial third layer so the first three layer are considered one unit Aponeurosis Dense Connective Tissue Connects the skin to the epicranial aponeurosis. It contains the vessels and nerves supplying the scalp. Epicranial Aponeurosis An aponeurotic tendon of occipitofrontalis muscle. Loose Areolar Connective Tissue Facilitates movement of the scalp over the skull bones. Pericranium Is the periosteum over the surface of the skull. 4 Scalp Lacerations Or scalp laceration Cut wound in the scalp: ‫جرح قطعي‬ a) Cut wound in dense connective tissue layer without involving the epicranial aponeurosis: The dense connective tissue surrounding the vessels tends to hold cut vessels open. This results in profuse bleeding The wound dose not gap (its edges remains close together) b) Cut wound involving the epicranial aponeurosis: The wound gaps widely because of the pull of the frontal and occipital bellies of the epicranius muscle in opposite directions. 5  Danger Area of the Scalp The loose connective tissue (fourth layer) is considered the “danger area” of the scalp. Means avulsion of the scalp for example in accident  In scalping injuries, this is the layer in which the separation occurs. The separation in the first three layers as a one unit Because fourth layer is loose connective tissue  Infection can easily spread in this layer. Because it loose connective tissue that allows to separate The bus and blood through it  Blunt trauma can result in hemorrhage in this layer (blood can spread forward into the face, because frontalis has no bony attachment, resulting in “black eyes”)  It contains the emissary veins – these are valveless veins which connect the extracranial veins of the scalp to the intracranial dural venous sinuses. The emissary veins are a potential pathway for the spread of infection from the scalp to the intracranial space. It can cause meningitis or can be life-threatening 6 Muscles of the Scalp Lateral view This third layer that means we remove first ( skin) and second layer (dense connective Occipitofrontalis ‫وجودة‬third ‫عضلة وحدة فقط م‬ layer ‫في ال‬ tissues) These anterior view we cannot see occipital It has two bellies: belly , you can see frontal belly of occipitofrontalis, the frontal belly attached Frontal belly of the occipitofrontalis: together in mid line Origin: Skin of the eyebrows. Insertion: Epicranial aponeurosis. No bone attachment Occipital belly of the occipitofrontalis: Origin: Highest nuchal line of the occipital bone. Insertion: Epicranial aponeurosis. Has bone attachment Action of occipitofrontalis muscles: Move the scalp. Raise the eyebrows, wrinkle the forehead. ‫فاجأة‬H‫ندهاش أو ا‬C‫خطوط الجبهة وهذا جزء من تعبير ا‬ Nerve supply: Motor innervation These posterior And occipital Facial nerve (Temporal branches for frontal belly & views we can’t see belly are frontal belly, and Separated from posterior auricular branch for occipital belly). occipital belly each other smaller than frontal belly 7 Sensory Innervation of the Scalp Is from two major sources, according to; A- Anterior to the ears and the vertex: By branches of the Trigeminal nerve [V] 5th cranial nerve : maxillary,mandibular, ophthalmic  Supratrochlear& Supra-orbital nerve; area of the scalp over forehead, up to the vertex. Branch of ophthalmic  Zygomaticotemporal nerve; area over a small anterior area of the temple. Branch of maxillary  Auriculotemporal nerve; area anterosuperior to the auricle. Branch of mandibular Spinal nerve B- Posterior to the ears and the vertex: By the cervical nerves.  Great auricular nerve; area just posterior to the auricle.  Lesser occipital nerve; area posterior& superior to the auricle.  Greater occipital nerve; area of posterior scalp up to the vertex.  Third occipital nerve; a small area of the lower part of the scalp. 8  Arterial Supply of Scalp Rich blood supply we have 10 arteries, 5 in the each side By; Three branches of the External Carotid Artery at each side: Superficial temporal. Posterior auricular. Occipital. Two branches of the ophthalmic artery of the Internal Carotid Artery at each side: Supratrochlear. branch or contentious of Supra-orbital. Internal Carotid Artery 9  Venous Drainage of the Scalp  Supratrochlear & Supra-orbital veins drain into the facial vein.  Superficial temporal vein join in the formation of the retromandibular vein.  Posterior auricular vein empties into a tributary of the retromandibular vein.  Occipital vein drains into the suboccipital venous plexus. 10 Lymphatic drainage of the scalp Lymphatics from: Back of the scalp drain into occipital nodes. Part of the scalp behind the ear drain into the mastoid nodes. Part of the scalp, anterior to the vertex drain to pre auricular nodes. Forehead to the submandibular nodes. 11 Face Face is the area of the unique organization of the various structures between the hair line superiorly, the lower edge of the mandible inferiorly, and as far back as the ears on either side. Forehead is common region between face and scalp 12 Muscles of the Face  They are subcutaneous, with origins from either bone or fascia, and insertions into the skin. is responsible for moving the skin  These muscles control expressions of the face, so referred to as muscles of “facial expression.” As they contract, they pull on the skin to exert their effects.  They also act as sphincters and dilators of the orifices of the face (i.e., the orbits, nose, and mouth)  They are innervated by branches of the facial nerve [VII]. Cranial nerve number 7  The facial muscles can broadly be categorized into three groups – orbital, nasal and oral 13  Orbital Group 1- Corrugator supercilii muscle. Means circle 2- Orbicularis Oculi muscle: Muscle that completely surrounds each orbital orifice and extends into each eyelid. It has three parts; Orbital, Palpebral& Lacrimal. Attachments;  Orbital part; Medial orbital margin &Medial palpebral ligament. Fibers form a broad ring around the orbit.  Palpebral part: Originates from the medial palpebral ligament, across each lid and inserts into the lateral palpebral raphe.  Lacrimal part: Deep part, originates from lacrimal bone. Inserts into margins of the eyelids. 14 Actions of Orbicularis Oculi muscle: Orbital part: Closure of the eyelids forcefully. Palpebral part: Closure of the eyelids gently, blinking. It keeps eyes wetTo prevent occurrence Keratitis to the cornea Lacrimal part: Helping the drainage of the tears. Innervation: Temporal & Zygomatic branches of the facial nerve. 15 Nasal Group Nasalis, Procerus &Depressor septi nasi. Action: Movements of the nose and the skin surrounding it. Compression or opening of the nasal aperture Inervation: Facial nerve (Zygomatic branch). 16 Oral Group They include the Orbicularis oris, Buccinator muscles, and various smaller muscles. Orbicularis Oris It is sphincter muscle of the mouth. Completely encircle the mouth. Origin: From the maxilla, mandible, buccinator and the other muscles. Insertion: Onto the skin and mucous membrane of the lips. Action: Closes the lips, protrudes the lips& compresses the lips against the teeth. Innervation: Buccal& marginal mandibular branches of the facial Risorius Risorius&depressor labii Depressor Mentalis nerve. inferioris anguli oris 17 Buccinator It forms the muscular component of the cheek. It fills the space between the mandible and the maxilla. Origin: From part of the maxilla & mandible opposite the molar teeth and the pterygomandibular raphe. Upper fibre insert in upper lip Insertion: Into the lips. Lower fibre insert in lower lip Middle fibre divide in upper lip and lower lip Action: It accessory muscle in Mastication It presses the cheek against the teeth, prevents accumulation of food in vestibule of the mouth. The space between teeth and cheek It assists in the forceful expulsion of air from the cheeks. Innervation: Buccal branches of the facial nerve. 18  Nerve supply of the Face 1-Motor innervation of the face:  Branches of the facial nerve [VII] innervate muscles of the face.exits through the stylomastoid foramen  After the facial nerve exits the cranial cavity, it enters the parotid gland.  Five terminal branches of the facial nerve emerge from the parotid gland. Temporal branches. Orbicularis Oculi muscle Nasal Group Zygomatic branches. Buccal branches Buccinator Orbicularis Oris Marginal mandibular branches. Cervical branches 19 Injury of facial nerve: Leads to paralysis of the facial muscles.  Paralysis of frontal belly: Loss of the wrinkles in the forehead on the paralysed side. He can’t rise eyebrows  Paralysis of orbicularis Occuli: Inability to close the eyelids – this can cause the cornea to dry out (exposure keratitis).  Paralysis of buccinator and orbicularis oris:  Inability to whistle or blow.  Saliva dribbles from the corner of mouth.  Angle of mouth is drawn towards the heathy side while smiling.  Food accumulates in the vestibule of mouth. 20  Buccal nerve branch of facial nerve that motor that supply 2- Sensory innervation of the face: Buccinator Buccal nerve branch of mandibular nerve that sensory that supply lower lip, chin, cheek Cutaneous innervation of the face is by branches of the Trigeminal nerve [V]. 5th cranial nerve Ophthalmic nerve (V1): Innervates: Upper third of the face (upper eyelid, skin of the forehead) Branches: Supraorbital, Supratrochlear … & Infratrochlear nerves. Maxillary nerve (V2): Innervates: Middle third of the face (lower eyelid, nose, skin of the zygomatic region& upper lip) Branches: Zygomaticofacial &Infraorbital nerves. Mandibular nerve (V3): Innervates: Lower third of the face (lower lip, chin, cheek). Branches: Buccal& Mental nerves. Except small area covering the angle of the mandible innervated by the great auricular nerve. 21 Arterial supply of the Face A. Branches of the External Carotid Artery. 1-Facial artery:  Major vessel supplying the face.  Passes up, winds around the lower border of the mandible.  Enters the face, runs upward and forward in a tortuous course. To avoid cutting due to the movement of the jaw and the movement of the facial muscles  Terminates as the angular artery at the medial corner of the eye.  Its branches in face: Inferior labial, Superior labial & Lateral nasal. 22 2- Transverse facial artery: 3- Branches of the Maxillary artery: Infra-orbital, Buccal & Mental arteries. B- Branches of the ophthalmic artery of the internal carotid artery: Supraorbital, Supratrochlear, Zygomaticofacial, Zygomaticotemporal & Dorsal nasal arteries 23 Venous drainage of the Face Facial vein: Drains into the internal jugular vein. Communicates with the superior ophthalmic vein and thus with the cavernous sinus, allowing a route of infection from the face to the cranial dural sinus. Transverse facial vein: Drains into the superficial temporal vein. 24  ‫إذا طلعله حبة ما *زم يضغط عليه *نه ممكن ال‬ ‫ إلى‬facial veins ‫ ينتقل عبر ال‬bus Danger area of the face: cavernous ‫ عن طريق‬intracranial  Is the area of the face on the side of the nose and venous sinus upper lip drained by the facial veins.  Skin infections in this area may spread to the cavernous venous sinus.  Facial vein communicates with the superior ophthalmic vein and thus with the cavernous sinus.  Facial connecting with the pterygoid plexus of veins through the deep facial vein  Pterygoid venous plexus of vein communicates with the cavernous sinus through emissary veins. 25 Lymphatic drainage of the face Lymphatics from the forehead and the anterior part of the face drains into the submandibular lymph nodes. Lymphatics from the lateral part of the face, drains into the parotid lymph nodes. Lymphatics from the lower lip& the chin are drained into the submental lymph nodes. 26 Quiz The muscle compresses cheek against molar Which nerve provides innervation to the area teeth is… of scalp behind the auricle? a. Risorius. a) Zygomaticotemporal b. Mentalis. b) Auriculotemporal c. Buccinator. c) Supraorbital d. Orbicularis oris. d) Lesser occipital e. Zygomaticus major. 27 28