Head, Face & Neck Anatomy (Y1B4M2L1) PDF

Y1B4M2L1 MUSCULOSKELETAL / INTEGUMENTARY SYSTEMS LECTURER DR. ARIK DE LA CRUZ OCTOBER 23, 2023 | 10 00 - 12 00 THE HEAD, FACE, AND NECK TABLE OF CONTENTS I. Head And Facial Muscle A. Rhytids And Botox 1. Rhytids 2. Botox 3. Facial Nerve Cranial Nerve 7 B. Facial Muscles 1. Frontalis Muscle 2. Glab...

Y1B4M2L1 MUSCULOSKELETAL / INTEGUMENTARY SYSTEMS LECTURER DR. ARIK DE LA CRUZ OCTOBER 23, 2023 | 10 00 - 12 00 THE HEAD, FACE, AND NECK TABLE OF CONTENTS I. Head And Facial Muscle A. Rhytids And Botox 1. Rhytids 2. Botox 3. Facial Nerve Cranial Nerve 7 B. Facial Muscles 1. Frontalis Muscle 2. Glabellar Frown Lines 3. Orbicularis Oculi 4. Eyebrow 5. Bunny Lines 6. Gummy Smile 7. Smokerʼs Lines 8. Marionetteʼs Lines 9. Cobblestone Chin 10. Turkey Gobbler Neck C. Muscles Of Mastication 1. Mumps D. Salivary Glands 1. Parotid Glands 2. Submandibular Glands 3. Sublingual Glands II. Neck Muscles: Back Vs Front A. Acute Neck Pain Management B. Posterior Back) Vs Anterior Front) 1. Sternocleidomastoid Muscle (Scm) 2. Torticollis III. Muscles, Back Of The Neck A. Posterior Neck Muscles 1. Trapezius 2. Scalenes 3. Semi-Spinalis Capitis 4. Splenius Capitis IV. Anterior Neck Muscles A. Anterior Neck Muscles B. Strap Muscles C. Suprahyoid Muscles D. Hyoid Bone E. Exposing The Thyroid Through The Strap Muscle F. Thyroid Gland G. Parts To Be Considered During Thyroidectomy 1. Arteries/Veins 2. Nerves 3. Parathyroids 4. Carotid Sheath 5. Cervical Trachea 6. Esophagus 7. Summary In Considerations During Thyroidectomy H. Lymph Nodes 1. Lymph Node Removal Post-Thyroidectomy) 2. Lymph Nodes Of The Neck 3. Lymph Node Levels 4. Lymphatic Drainage 5. Superficial Lymph Nodes I. Emergency Tracheostomy 1. Review The Layers Of The Neck 2. Tracheostomy Procedure J. Heimlich Maneuver V. Review Questions → When you are younger, your skin is still plump and the elasticity is okay. When we get older, our skin gets thinner. → Ex: Crowʼs feet, frown lines, figure 11 (glabellar frown lines), etc. BOTOX ● Botulinum toxin is a synthetic toxin made from Clostridium botulinum ● It prevents the release of acetylcholine at the neuromuscular junction resulting in paralysis. ● Paralyzing the muscle in an aging person in a very strategic way prevents the muscle from creasing the skin. ○ Typical points in the face or muscles are targeted to relieve wrinkles Figure 1. Skin creases produced by the pull of the muscles of the face. I. HEAD AND FACIAL MUSCLES A. RHYTIDS AND BOTOX ● The skin tends to be thinner over time and with facial expressions, the muscle that pulls the skin tends to wrinkle the skin which becomes more prominent as people age. RHYTIDS ● Skin creases wrinkles in the face ○ Wrinkles have two mechanisms of action: 1 thinning of the skin, 2 pulling of muscle. Lecturerʼs Notes: ● There are 2 types of wrinkles: ○ 1 Static - permanent lines; older ○ 2 Dynamic - temporary lines; when you were younger ○ Some are produced by the static pull of facial muscles on the skin Figure 2. Facial muscles producing creases. FACIAL NERVE CRANIAL NERVE 7 ● Innervates the facial muscles ● Exits from the brainstem from the stylomastoid foramen (behind and underneath the ear) ● Goes forward, passes through the parotid gland and divides into branches/divisions ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 1 of 17 Y1B4M2L1 THE HEAD, FACE & NECK ● Upper division ○ Temporal branch – innervates the upper facial muscles, muscles near the eyebrow ○ Zygomatic branch – muscles of the cheek, nose and upper lips ● Lower division ○ Buccal branch – lower cheek and lip ○ Mandibular branch – chin ○ Cervical branch – neck ORBICULARIS OCULI ● Insertion and origin: Medial palpebral ligament ○ When ligament contracts and shortens it causes eyes to squint and skin around the eyes to fold ● Circular muscle around the eye ○ This is why the wrinkle is also circular. ● “Crowʼs feet” ● Botox is usually injected at the lateral side ● Be careful when injecting botox because just underneath the orbicularis oculi you can find the nearby smiling muscles. ● Smiling muscles – pulls lips upwards producing a smile ○ Zygomaticus minor ○ Zygomaticus major Figure 3. Facial nerve Cranial Nerve 7 innervating the facial muscles. B. FACIAL MUSCLES FRONTALIS MUSCLE “Frown lines” Raises the eyebrow Produces wrinkles or frown lines on the forehead It is absent at the middle, so creases are not observed at that part. ● If you apply botox or paralyze the frontalis muscle, wrinkles on the forehead will improve ● ● ● ● Figure 5. Zygomaticus minor and Zygomaticus major. ● Also known as Figure 11 ○ Present in between the eyes ○ Produces the 11 line between the eyebrows ○ Muscles responsible for this creasing are: → Procerus – when it contracts, it lowers the medial eyebrow and produce creasing → Corrugator supercilii – triangular muscles on the lateral end of procerus; when it contracts, it makes the medial side of the eyebrow meet together ● Orbicularis oculi is the area where several muscles of the face insert ○ Specifically, the smiling muscles insert into this corner of the mouth ● Movement of the mouth is a concert of the many actions of the several muscles of the face area ● Upward: ○ Levator Labii Superioris - raises lips upward ○ Levator Anguli Oris - raises angle of the mouth upward → Literally: “to angle the mouth, you elevate it” ● Sideways: ○ Risorius ○ Buccinator - much deeper ● Downward: ○ Depressor Anguli Oris DAO ○ Depressor Labii Inferioris - depresses lips inferiorly Figure 4. Frontalis muscle, procerus (yellow arrow) and corrugator supercilii (blue arrow). Figure 6. Smiling muscles. Red arrow points at the modiolus. GLABELLAR FROWN LINES ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 2 of 17 Y1B4M2L1 THE HEAD, FACE & NECK EYEBROW ● Eyebrow Shaping ○ The brow is both being moved by the: → Frontalis – pull upward → Orbicularis oculi – pulls downward ○ Antagonistic actions ○ Botox takes advantage of the actions of muscles in one area ○ In botox, if one muscle is paralyzed, the net action raises the eyebrow because there is no opposing muscle that opposes the frontalis, resulting in the lifting of the eyebrow Figure 9. Before and after photo of the botox procedure minimizing gummy smile. SMOKER'S LINES Figure 7. Opposing actions of the muscles in the eyebrow. ● Wrinkles around the mouth ● Produced by the action of: Orbicularis oris ○ When we get older, this muscle tends to be hyperactive and produce a crease that is circular in nature. ● Orbicularis oris ○ Circular muscle around the mouth ○ When it contracts it produces a wrinkle around the mouth ● In botox, one should only paralyze some of the orbicularis oris, not all so as to still have control with the mouth BUNNY LINES ● Wrinkles found in the nose ● Produced by Levator Labii Superioris Alequae Nasi LLSAN) and Nasalis ○ LLSAN – connecting the lips and nasal bridge ○ Nasalis muscle - surrounds the nose → Botox is injected in both sites to remove the skin creases of the nose. ● Both muscles have to be paralyzed to get rid or minimize bunny lines Figure 10. Smokerʼs line Figure 8. Muscles producing bunny lines: Levator Labii Superioris Alequae Nasi (left) and Nasalis (right) ● The Orbicularis oris is not formed in Cleft Lip Babies ○ This is an inborn deformity of the orbicularis oris wherein it is not continuous with each other. ○ It instead inserts into the nostrils and pulls it to the side ○ The cleft side will pull the ala on the other side. ○ Surgeon has to repair the skin and the orbicularis oris. The muscles have to be connected together. GUMMY SMILE ● Smile that show more gums ● Muscle pulls a little bit more upward ● Muscle responsible: Levator Labii Superioris Alequae Nasi LLSAN ○ The LLSAN is too hyperactive in persons with gummy smiles. ○ Paralyzing the LLSAN makes the lip droop down and hide the gums when smiling Figure 11. Cleft lip ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 3 of 17 Y1B4M2L1 THE HEAD, FACE & NECK MARIONETTEʼS LINES ● Wrinkle produced by Depressor Anguli Oris DAO ● Depressor Anguli Oris ○ Pulls the skin downward and forward ○ Usually also treated with a “filler” such as hyaluronic acid since paralysis is not enough. This elevates the skin aside from reducing the wrinkle. ● In botox, one should not inject near the Depressor Labii Inferioris DLI because if it is paralyzed, the patient will not be able to move the lips downward and thus will have an asymmetrical left and right mouth movement. Figure 15. Cobblestone chin TURKEY GOBBLER NECK ● Occurs when a muscle in the neck produces a very prominent creasing ● Muscle is very active yet the skin is very loose ● Also known as “Platysmal bands” ● Caused by Platysma muscle ○ Reaches left to right sides of face ○ Clavicles to the sides of the face ○ Used in clenching of teeth and expressing anger ● When people get older the platysma will be more prominent ● Botox is injected and this paralyzes the muscle to get rid of “turkey gobbler neck” Figure 12. Marionetteʼs lines Figure 16. Turkey Gobbler Neck Figure 13. Depressor Anguli Oris COBBLESTONE CHIN ● Caused by the mentalis muscle ○ Mentalis muscle pulls the skin of the chin upward and underneath that will cause wrinkling ● This is paralyzed to relieve the wrinkling Figure 17. Platysma muscles C. MUSCLES OF MASTICATION Figure 14. Cobblestones (left) and Mentalis muscles Right) ● Includes the following: ○ Masseter ○ Temporalis ○ Medial Pterygoid ○ Lateral Pterygoid → The first three: Masseter, Temporalis and Medial Pterygoid closes the jaw ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 4 of 17 Y1B4M2L1 THE HEAD, FACE & NECK → The last one: Lateral Pterygoid is the only one that opens the jaw APPROACH TO MUMPS : ● Viral ● Supportive measures ○ Hydration ○ Oral Hygiene ○ Pain control ○ Bed rest and isolation ● Vaccination ○ Mumps vaccine is available to babies at 12 15 months D. SALIVARY GLANDS Figure 18. Muscles of mastication. ● Masseter muscle ○ Controls the jaw by inserting into the mandible ○ Botox injection in this muscle will result to a V-shaped jaw ● Temporalis ○ A very big muscle spanning the temples ○ Inserts into the jaw ● Medial Pterygoid ○ Found underneath the other 2 muscles ○ Closes the jaw ● Lateral Pterygoid ○ Also under the masseter and temporalis ○ Opens the jaw ● Muscles of Mastication is “3 vs 1” ○ 3 closes and 1 opens ○ This means that the net action is to close ○ Hence, when there are spasms in that area the net action is also to close ○ Prominent in clinical cases, such as tetanus infection Clostridium tetani infection) → Spasms of muscles → More prominent in muscles of mastication → Patients will have locked jaw because of the net action ● Glands that produce saliva ● Three main types: ○ Parotid glands ○ Submandibular gland ○ Sublingual glands Figure 20. Salivary glands. PAROTID GLANDS ● Major salivary gland ● Found in pre-auricular area specifically anterior to the ear or angle of the jaw ○ Pre-auricular means before the auricle ● Produces majority of stimulated saliva ○ Stimulated saliva - produced during eating, chewing, sight of food stimulations, etc. ● Stensenʼs Duct - carries it inward into the mouth and pierces through the buccinator muscle ○ The parotid glands produces the saliva and transports it through the Stensenʼs Duct ○ It drains through the buccal cavity opposite the 2nd maxillary molar Figure 19. Patient with a locked jaw due to a tetanus infection 10AM CASE SCENARIO - Medical Clinic at Molo: ● Patient 1 14/M with pre-auricular mass, left ○ Patient presents with 3 days of progressive facial and neck swelling, exposed to a mumps outbreak at school. MUMPS ● Mumps viral infection spreads through saliva, nasal secretions and primarily affects the parotid glands. SUBMANDIBULAR GLAND ● Located below the floor of the mouth and more anterior to the angle of the jaw ● Produces majority of unstimulated saliva ○ Unstimulated saliva is produced by autonomic stimulation ○ At rest (e.g. sleeping) ● Whartonʼs duct ○ Duct of the submandibular gland ○ Courses underneath the mylohyoid muscle ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 5 of 17