Y1B4M2L1 - The Head, Face, and Neck (Lecturer Notes) PDF

Y1B4M2L1 LECTURER: DR. ARIK DE LA CRUZ MUSCULOSKELETAL / OCTOBER 23, 2023 | 10:00 - 12:00 INT...

Y1B4M2L1 LECTURER: DR. ARIK DE LA CRUZ MUSCULOSKELETAL / OCTOBER 23, 2023 | 10:00 - 12:00 INTEGUMENTARY SYSTEMS THE HEAD, FACE, AND NECK TABLE OF CONTENTS Lecturer Notes: There are 2 types of wrinkles: I. Head And Facial Muscle 2. Scalenes ○ Static - permanent lines; older A. Rhytids And Botox 3. Semi-spinalis Capitis ○ Dynamic - temporary lines; when you were younger 1. Rhytids 4. Splenius Capitis 2. Botox IV. Anterior Neck Muscles ○ Some are produced by the static pull of facial muscles on 3. Facial Nerve (Cranial A. Anterior Neck Muscles the skin Nerve 7) B. Strap Muscles → When you are younger, your skin is still plump and the B. Facial Muscles C.Suprahyoid Muscles elasticity is okay. When we get older, our skin gets 1. Frontalis Muscle D. Hyoid Bone thinner. 2. Glabellar Frown Lines E. Thyroidectomy → Ex: Crow’s feet, frown lines, figure 11 (glabellar frown 3. Orbicularis Oculi F. Thyroid Gland lines), etc. 4. Modiolus G.Parts To Be Considered 5. Eyebrow During Thyroidectomy BOTOX 6. Bunny Lines 1. Arteries/Veins Botulinum toxin is a synthetic toxin made from Clostridium 7. Gummy Smile 2. Nerves botulinum 8. Smoker’s Lines 3. Parathyroid Glands It prevents the release of acetylcholine at the neuromuscular 9. Marionette’s Lines 4. Carotid Sheath junction resulting in paralysis. 10. Cobblestone Chin 5. Cervical Trachea Paralyzing the muscle in an aging person in a very strategic 11. Turkey Gobbler 6. Cervical Esophagus way prevents the muscle from creasing the skin. Neck 7. Summary of ○ Typical points in the face or muscles are targeted to relieve C.Muscles Of Mastication Thyroidectomy wrinkles 1. Mumps H.Lymph Nodes D. Salivary Glands 1. Lymph Node Removal 1. Parotid Glands (Post-Thyroidectomy) 2. Submandibular 2. Lymph Nodes Of The Glands Neck 3. Sublingual Glands 3. Lymph Node Levels II. Neck Muscles: Back Vs 4. Lymphatic Drainage Front 5. Superficial Lymph A. Acute Neck Pain Nodes Management I. Emergency B. Posterior (Back) Vs Tracheostomy Anterior (Front) 1. Review The Layers Of 1. Sternocleidomastoid The Neck Muscle (Scm) 2. Tracheostomy 2. Torticollis Procedure III. Muscles, Back Of The J. Heimlich Maneuver Figure 1. Skin creases produced by the pull of the muscles of the Neck V. Review Questions face. A. Posterior Neck Muscles VI. Appendix 1. Trapezius 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. Figure 2. Facial muscles producing creases. ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 1 of 18  Y1B4M2L1: THE HEAD, FACE & NECK 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 Upper division ○ Temporal branch – innervates the upper facial muscles, muscles near the eyebrow ○ Zygomatic branch – innervates the muscles of the cheek, nose and upper lips Lower division ○ Buccal branch – lower cheek and lip ○ Mandibular branch – chin ○ Cervical branch – neck Figure 4. Frontalis muscle, procerus (yellow arrow) and corrugator supercilii (blue arrow). 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. “Crow’s 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 Figure 3. Facial nerve (Cranial Nerve 7) innervating the facial ○ Zygomaticus major 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 GLABELLAR FROWN LINES Also known as Figure 11 ○ Present in between the eyes ○ Produces the 11 line between the eyebrows Figure 5. Zygomaticus minor and Zygomaticus major. ○ Muscles responsible for this creasing are: → Procerus – when it contracts, it lowers the medial MODIOLUS eyebrow and produce creasing Area where several muscles of the face insert → Corrugator supercilii – triangular muscles on the ○ Specifically, the smiling muscles insert into this corner of lateral end of procerus; when it contracts, it makes the the mouth medial side of the eyebrow meet together 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) ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 2 of 18  Y1B4M2L1: THE HEAD, FACE & NECK ○ Depressor Labii Inferioris - depresses lips inferiorly Figure 8. Muscles producing bunny lines: Levator Labii Superioris Alequae Nasi (left) and Nasalis (right) GUMMY SMILE Smile that show more gums Figure 6. Smiling muscles. Red arrow points at the modiolus. Muscle pulls a little bit more upward Muscle responsible: Levator Labii Superioris Alequae Nasi EYEBROW (LLSAN) ○ The LLSAN is too hyperactive in persons with gummy Eyebrow Shaping smiles. ○ The brow is both being moved by the: ○ Paralyzing the LLSAN makes the lip droop down and hide → Frontalis – pull upward the gums when smiling → 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 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. Figure 7. Opposing actions of the muscles in the eyebrow. Orbicularis oris ○ Circular muscle around the mouth BUNNY LINES ○ When it contracts it produces a wrinkle around the mouth Wrinkles found in the nose In botox, one should only paralyze some of the orbicularis oris, Produced by Levator Labii Superioris Alequae Nasi (LLSAN) not all so as to still have control with the mouth 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 ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 3 of 18  Y1B4M2L1: THE HEAD, FACE & NECK Figure 13. Depressor Anguli Oris Figure 10. Smoker’s line The Orbicularis oris is not formed in Cleft Lip Babies COBBLESTONE CHIN ○ This is an inborn deformity of the orbicularis oris wherein it is not continuous with each other. Caused by the mentalis muscle ○ It instead inserts into the nostrils and pulls it to the side ○ Mentalis muscle pulls the skin of the chin upward and ○ The cleft side will pull the ala on the other side. underneath that will cause wrinkling ○ Surgeon has to repair the skin and the orbicularis oris. The This is paralyzed to relieve the wrinkling muscles have to be connected together. Figure 14. Cobblestones (left) and Mentalis muscles (Right) Figure 11. Cleft lip MARIONETTE’S 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 Figure 15. Cobblestone chin Inferioris (DLI) because if it is paralyzed, the patient will not be able to move the lips downward and thus will have an TURKEY GOBBLER NECK asymmetrical left and right mouth movement. 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. Marionette’s lines ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 4 of 18  Y1B4M2L1: THE HEAD, FACE & NECK ○ 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 Figure 16. Turkey Gobbler Neck Figure 19. Patient with a locked jaw due to a tetanus infection Figure 17. Platysma muscles 10AM CASE SCENARIO - Medical Clinic at Molo: Patient 1: 14/M with pre-auricular mass, left C. MUSCLES OF MASTICATION ○ Patient presents with 3 days of progressive facial and neck swelling, exposed to a mumps outbreak at school. Includes the following: ○ Masseter ○ Temporalis MUMPS ○ Medial Pterygoid Mumps viral infection spreads through saliva, nasal ○ Lateral Pterygoid secretions and primarily affects the parotid glands. The first three: Masseter, Temporalis and Medial Pterygoid close the jaw APPROACH TO MUMPS The last one: Lateral Pterygoid is the only one that opens the : jaw Viral Managed by 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 Glands that produce saliva Figure 18. Muscles of mastication. Three main types: ○ Parotid glands Masseter muscle ○ Submandibular gland ○ Controls the jaw by inserting into the mandible ○ Sublingual glands ○ 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 ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 5 of 18  Y1B4M2L1: THE HEAD, FACE & NECK Figure 21. Mylohyoid muscle SUBLINGUAL GLANDS Figure 20. Salivary glands. Found underneath the lingua or the tongue Minor salivary glands PAROTID GLANDS Compared to the other glands, it has multiple openings Major salivary gland Ducts of Rivinus Found in pre-auricular area specifically anterior to the ear or ○ Several ducts of the the sublingual gland that drain into the angle of the jaw floor of the mouth ○ Pre-auricular means before the auricle Produces majority of stimulated saliva ○ Stimulated saliva - produced during eating, chewing, sight of food stimulations, etc. Stensen’s Duct - carries it inward into the mouth and pierces through the buccinator muscle ○ The parotid glands produces the saliva and transports it through the Stensen’s Duct ○ It drains through the buccal cavity opposite the 2nd maxillary molar SUBMANDIBULAR GLAND Located below the floor of the mouth and more anterior to the Figure 22. Salivary Glands showing Ducts of Rivinus (at the floor angle of the jaw of the mouth). Produces majority of unstimulated saliva ○ Unstimulated saliva is produced by autonomic stimulation II. NECK MUSCLES: BACK VS FRONT ○ At rest (e.g. sleeping) Wharton’s duct 10AM CASE SCENARIO - Medical Clinic at Molo: ○ Duct of the submandibular gland Patient 2: 22/F complaining of stiff neck ○ Courses underneath the mylohyoid muscle ○ Patient woke up with a very deep aching pain, stiffness more emphasized on neck movement, after her first time Mylohyoid muscle working out at home. ○ The floor of the mouth. ○ Drains through the floor of the mouth just beside the A. ACUTE NECK PAIN MANAGEMENT frenulum of the tongue ○ Lateral to the frenulum are the openings of the wharton’s Muscle strain (myalgia) to the neck occurs when muscles at duct the back of the neck become inflamed due to exertions, ○ In some babies, the frenulum is very thick which causes prolonged static loads, repetitive work and poor position. tongue tie hence, limiting the movement of the tongue Management include: especially when talking ○ Massage ○ The mylohyoid muscle is one of the muscles that forms the ○ Physical Therapy floor of the mouth otherwise the tongue will just fall down. ○ Paracetamol and other Nonsteroidal Anti-Inflammatory Drugs or NSAID (Mefenamic acid, Ibuprofen, Naproxen, Diclofenac) as pharmacologic management ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 6 of 18  Y1B4M2L1: THE HEAD, FACE & NECK B. POSTERIOR (BACK) VS ANTERIOR (FRONT) STERNOCLEIDOMASTOID MUSCLE (SCM) Used as a line guide since it divides the neck into the posterior and anterior regions ○ Posterior neck - anything at the back of the line ○ Anterior neck - anything in front of the line Rotates the head to opposite side, very big muscle Connects the mastoid bone, sternum and clavicle ○ Has 2 bellies: → Connects sternum and mastoid → Connects clavicle and mastoid Figure 24: Trapezius muscle Figure 23. Sternocleidomastoid Muscle TORTICOLLIS A pathology of the sternocleidomastoid muscle (SCM) ○ When SCM becomes hypertrophic → Enlarged on one side and weak on the other ○ Net movement of head in one side Figure 25. Well-developed trapezius muscle in bodybuilders ○ Small/shortened or absent SCM on one side and normal SCM on the other SCALENES 2 Types: ○ Congenital Torticollis Anterior, middle and posterior ○ Acquired Torticollis Removing the trapezius and sternocleidomastoid muscles out → Cervical dystonia will reveal the scalenes There is a gap between anterior and middle scalene III. MUSCLES, BACK OF THE NECK ○ Because it is where the subclavian artery and brachial plexus exit the neck A. POSTERIOR NECK MUSCLES ○ Subclavian artery Includes the following: ○ Brachial plexus - a network of nerves that goes into the ○ Sternocleidomastoid (SCM) arms ○ Trapezius ○ Anterior/ middle/ posterior scalenes ○ Semi-spinalis capitis ○ Splenius capitis → Capitis means head. The semi-spinalis capitis and splenius capitis are two muscles found near the head at the back. TRAPEZIUS “TRAPS” Support and maintain head posture so that the head won’t arch forward, and also the shoulders and the back Responsible for shrugging action Figure 26. Scalene Muscles Big muscle that spans the back of the neck, shoulder and the back SEMI-SPINALIS CAPITIS ○ It inserts into the back of the head, shoulders, and the Found at the back near the head lower back Deeper than splenius capitis The left and right trapezius forms a diamond shape Function to hold the head in place Some people like bodybuilders have a very well-developed Help flex the head from one side to the other traps by doing shrugs with a weighted object ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 7 of 18  Y1B4M2L1: THE HEAD, FACE & NECK → Reach the thyroid gland and remove it safely from the surrounding structures: Laryngeal Nerves Parathyroid glands Carotid vessels Trachea Esophagus → Remove all the neck nodes Figure 27. Splenius Capitis & Semi-spinalis capitis SPLENIUS CAPITIS Also found at the back near the head Similarly, function to hold the head in place Also to flex the head from one side to the other IV. ANTERIOR NECK MUSCLES 2:00 PM CASE SCENARIO: “This is a case of a 70/M who presented with a 5-year history of left anterior neck mass, and 3 months enlarged lymph nodes, left. A needle biopsy was done on the mass and it revealed Thyroid Cancer.” Figure 29. Anatomy of papillary thyroid cancer. A. ANTERIOR NECK MUSCLES Platysma ○ Goes before the strap muscles ○ Most superficial Strap Muscles Figure 28. Anterior neck mass and enlarged lymph nodes. Surgical Plan: Total Thyroidectomy with Neck Dissection Thyroidectomy - surgical procedure of removing the thyroid because of factors such as cancers ○ Thyroidectomy is a very challenging procedure because the thyroid should be removed in a safe way so that it won’t damage all the surrounding structures Papillary thyroid cancer (PTC) - most common thyroid cancer ○ Usually spreads (metastasize) through the neck lymph nodes ○ Total thyroidectomy is the first treatment of choice. → It involves getting the left and right thyroid. Figure 30. Platysma → Followed by removal of neck nodes (neck dissection) → This will allow treatment of the primary tumor and also the neck nodes wherein the tumor has spread ○ Procedure: → Open muscles of the anterior neck Thyroid is situated deep into the neck. It is covered by the anterior neck muscles ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 8 of 18  Y1B4M2L1: THE HEAD, FACE & NECK C. SUPRAHYOID MUSCLES Above the hyoid bone Primarily functions to support the mouth Types: ○ Geniohyoid - spans from the middle of the mandible to the hyoid bone; floor of the mouth ○ Mylohyoid - floor of the mouth → Mylohyoid and Geniohyoid combined forms the floor of the mouth. They support the mouth and the tongue. ○ Stylohyoid - muscle that spans the hyoid bone and styloid process ○ Digastrics - V-shaped muscles → Have 2 bellies: the anterior and the posterior belly → Support the floor of the mouth Figure 31. Overall components of the strap muscles. B. STRAP MUSCLES Called the infrahyoid muscles since they are found below the hyoid bone Has four sets on each side of the neck Joined in the midline by a tissue Composed of four muscles: ○ Sternohyoid - muscle that spans the whole anterior neck from the sternum to the hyoid bone ○ Omohyoid - a unique muscle which comes from the hyoid bone and goes down and then sideways → Unique since it is the only strap muscle that goes sideways Figure 34. Frontal View of the Suprahyoid Muscles ○ Thyrohyoid - spans the hyoid bone and thyroid cartilage ○ Sternothyroid - spans the sternum and thyroid cartilage Figure 35. Lateral View of the Suprahyoid Muscles Figure 32. Frontal view of the strap muscles. D. HYOID BONE Horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage A “Floating bone” and “Suspension bone” ○ Not attached to another bone (floats due to the tension of the muscles above and below it) ○ Suspended by the muscles above and muscles below it ○ Delineate the infra- and suprahyoid muscles. Functions: ○ Supports the infrahyoid and suprahyoid bones ○ Determines the cervico-mental angle → Cervico - neck → Mental - area below the chin Figure 33. Lateral view of the strap muscles. ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 9 of 18  Y1B4M2L1: THE HEAD, FACE & NECK Figure 39. Exposing the thyroid through the strap muscle. Figure 36. Cervico-Mental Angle Figure 37. Comparison of hyoid bone position in relation to cervico-mental angle. Figure 40. Median raphe/midline fascia Figure 38. Varying cervico-mental angle in relation to hyoid bone orientation. E. THYROIDECTOMY Exposing the thyroid through the strap muscle ○ “Open” strap muscles ○ Retract the left and right strap muscles (4 sets on each side of the neck) → Like opening a curtain (no need to cut because it is joined by a thin fibrous tissue called the median raphe/midline fascia) After retracting the strap muscles, thyroid gland is exposed. Figure 41. Strap muscle F. THYROID GLAND “Butterfly-shaped” gland Composed of: ○ Right thyroid lobe ○ Left thyroid lobe → Each lobe is approximately 5 cm x 3 cm x 2 cm in dimension ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 10 of 18  Y1B4M2L1: THE HEAD, FACE & NECK → Having 6 cm thyroid lobe already indicates a goiter or ○ Middle thyroid vein enlargement of the thyroid gland. ○ Inferior thyroid vein ○ Isthmus - bridges the right and left thyroid lobes → 1.3 cm in size ○ Pyramidal lobe - usually at the middle Function: produce thyroid hormones Anatomic position: hugs the cricoid and trachea (C5) Figure 42. Thyroid gland. The thyroid gland is distinct from the the thyroid cartilage (Adam’s apple) Figure 44. Three veins you need to be careful with during The thyroid gland hugs the cricoid and trachea like a koala thyroidectomy. Swallowing is a technique when assessing patients with thyroid abnormalities such as tumor or masses ○ The trachea elevates when swallowing thus, thyroid also NERVES goes up alongside it, allowing delineation of thyroid Most important part of the surgery tumor/masses RECURRENT LARYNGEAL NERVES G. PARTS TO BE CONSIDERED DURING THYROIDECTOMY Recurrent Laryngeal Nerves (RLN) has two components: When cutting off the thyroid (Thyroidectomy), we need to be ○ Left and Right RLN careful with the following parts: ○ Found just at the back of the thyroid gland and tracheal groove ARTERIES / VEINS Function: Control of voice box Three Arteries Loss of RLN will result to hoarseness ○ Superior thyroid artery ○ Inferior thyroid artery ○ Thyroid ima artery Figure 45. Left and right RLN Figure 43. Three arteries you need to be careful with during thyroidectomy. Three Veins ○ Superior thyroid vein ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 11 of 18  Y1B4M2L1: THE HEAD, FACE & NECK Figure 48. Location of parathyroid glands. Figure 46. Location of RLN at the back of thyroid gland and tracheal groove. EXTERNAL BRANCH OF THE SUPERIOR LARYNGEAL NERVE External Branch of the Superior Laryngeal Nerve (EBSLN) has two components: ○ Left and Right EBSLN ○ Located near the upper pole of each thyroid lobes and inserts into the cricothyroid muscle Figure 49. Actual view of parathyroid glands. Functions: ○ Innervates the cricothyroid muscle Lecturer Notes: ○ Controls the pitch of voice During thyroidectomy, sometimes you need to preserve at Loss will result to inability to reach high notes least one or two PT gland since complete loss of it will result to hypocalcemia, which will result to cramps, muscle Lecturer Notes: spasms, and paresthesia (nerve numbness). Nerve is sometimes called Galli-Curci nerve Amelita Galli-Curci was an opera singer who lost her high CAROTID SHEATH notes after her thyroidectomy since her EBSLN was cut. Sheath on either side of the thyroid gland which contains the following: ○ Carotid artery - the main artery to the brain and head → If damaged or cut, it will result to reduced blood to the brain which may lead to stroke ○ Jugular vein ○ Vagus nerve → Functions: responsible for the functions of internal organs (digestion, heart and respiratory rate, etc) → It branches out to the recurrent laryngeal nerve and the superior laryngeal nerve Figure 47. Location of EBSLN PARATHYROID GLANDS Composed of four glands: ○ Two superior parathyroid glands ○ Two inferior parathyroid glands → Parathyroid glands are found posterior to the thyroid gland. Function: Secretes parathyroid hormone (PTH) Figure 50. Components of the Carotid Sheath Parathyroid hormone (PTH) - regulates calcium and phosphate metabolism ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 12 of 18  Y1B4M2L1: THE HEAD, FACE & NECK Layers in performing surgery of the thyroid gland: ○ Skin ○ Platysma ○ Strap muscles ○ Thyroid gland ○ Cut off veins & arteries Figure 52. Thyroidectomy H. LYMPH NODES LYMPH NODE REMOVAL (POST-THYROIDECTOMY) Neck dissection is the procedure wherein we remove the lymph nodes from sides of the neck into which cancer cells may have migrated. Typically, a Papillary Thyroid Carcinoma (PTC) spreads through lymph nodes of the neck. Figure 51. Carotid Sheath CERVICAL TRACHEA Has corrugation structures, thus it is usually identified as “Corrugated Cartilage” Location: ○ Back of thyroid gland ○ Usually midline, but can move ○ Starts at the C6 vertebra ○ Posteriorly, it is united by smooth muscle called trachealis Composed of: 15 to 20 U-shaped rings of hyaline cartilage Damage, cut, or perforation of cervical trachea will lead to leakage of air into the neck which will result in air pockets on the neck (like sounds of popped bubble wraps) called Figure 53. Thyroid cancer (invasive tumor) that may spread subcutaneous emphysema. (metastasize) through the neighboring lymph nodes. CERVICAL ESOPHAGUS LYMPH NODES OF THE NECK Location: ○ Just at the back of the trachea The neck has abundant lymph nodes; they appear like ○ Starts the C5-6 vertebrae at the level of the cricoid “beans” scattered all over the neck. cartilage Functions: Function: Muscular tube which allows food to pass through ○ Lymphatic system: going into the stomach → Filtration Damage, cut, or perforation of esophagus will lead to leakage → Immunity of saliva and food into the neck which will cause deep-neck Cancers can spread through these lymph channels and get infection. trapped in these lymph nodes SUMMARY OF THYROIDECTOMY Open the skin Retract the left and right strap muscles Partial removal of thyroid Important to preserve the nerves Important to preserve the trachea and esophagus Figure 54. Lymph nodes of the neck ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 13 of 18  Y1B4M2L1: THE HEAD, FACE & NECK Lymph nodes in the neck are organized according to “Levels” ○ This will help doctors to describe better the location of lymph nodes in the neck We have 7 Levels of Lymph Nodes in the neck Figure 57. Actual lymph nodes showing levels I, II, III, and IV LYMPHATIC DRAINAGE Lymphatic drainage from the head and neck region is extensive. Lymph vessels usually converge in the neck. Areas should not be normally felt upon palpation; if swollen, Figure 55. Lymph node levels underlying problems may be present. LYMPH NODE LEVELS Level 1 ○ In front of Sternocleidomastoid (SCM) and above hyoid ○ In front of digastric muscle (either anterior or posterior bellies) Level 2, 3, 4 ○ Within the SCM ○ Important horizontal lines (delineations): → Hyoid → Cricoid ○ Level 2 – Within SCM, above hyoid ○ Level 3 – Within SCM, below hyoid, above cricoid ○ Level 4 – Within SCM, below cricoid Level 5 Figure 58. Flow of lymph from the head, face, and neck. ○ Posterior neck Level 6 ○ In front of SCM and below hyoid Figure 59. Lymph drainage of the head and neck SUPERFICIAL LYMPH NODES Superficial lymph nodes – lie along the external jugular vein Figure 56. Case of neck (thyroid) mass with lymph node superficial to the sternocleidomastoid muscle enlargement. The mass is indicated by the red circle while the ○ Receive lymph vessels from the occipital and mastoid lymph nodes are indicated by the yellow arrows lymph nodes Based on the figure above, probably, Level 3 lymph nodes are ○ Drain into the deep cervical lymph nodes affected. ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 14 of 18  Y1B4M2L1: THE HEAD, FACE & NECK Figure 62. Upper airway obstruction blocking airflow to and from the lungs Emergency tracheostomy – bypasses the obstruction and Figure 60. Superficial lymph drainage of the head and neck. allows the patient to breathe (Snell’s, 9th Ed.) Figure 63. Tracheostomy tube placed inside the trachea Figure 61. Superficial lymphatic system in the head and neck REVIEW THE LAYERS OF THE NECK (Gray’s Anatomy, 40th Ed.) The nodes are organized into a superficial group around the head, superficial cervical nodes along the external jugular vein, and deep cervical nodes along the internal jugular vein. I. EMERGENCY TRACHEOSTOMY 8:00 PM CASE SCENARIO – McDonald’s: Finished surgery at 7:00 PM. waited for the patient to wake up before heading home. Passed by McDonald’s to have a quick dinner. You witnessed someone choking after eating some chicken nuggets. You remembered you have a Tracheostomy Set in your car. Tracheostomy set – set of instruments used in a tracheostomy procedure Tracheostomy – placement of a tube into the neck to allow a Figure 64. Dissection of the neck. patient to breathe in the presence of an upper airway Structures before the trachea (from most superficial): obstruction ○ Skin Normal direction of air during inhalation: nose → larynx → ○ Platysma trachea → lungs ○ Strap muscles (left and right) Upper airway obstruction – choking or obstruction (e.g. food, ○ Thyroid foreign materials, cancer) above the trachea ○ Trachea ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 15 of 18  Y1B4M2L1: THE HEAD, FACE & NECK TRACHEOSTOMY PROCEDURE V. REVIEW QUESTIONS 1. What is the muscle that divides the posterior and anterior triangles of the neck? It is also responsible for the rotation of the head. a. Mylohyoid muscle b. Scalene c. Trapezius d. Sternocleidomastoid 2. What muscles should be paralyzed to get rid of Bunny lines? a. Levator labii superioris alaeque nasi and Orbicularis Oris b. Frontalis and Nasalis c. Orbicularis Oris and Frontalis d. Levator labii superioris alaeque nasi and Nasalis Figure 65. Tracheostomy procedure. 3. What muscle should be avoided when getting rid of Crow’s feet The incision is placed midway between the cricoid cartilage around the eyes? and the suprasternal notch. a. Zygomaticus minor and major The investing layer of fascia covering the pretracheal muscles b. Depressor Anguli Oris (strap muscles) is exposed. c. Orbicularis Oris The isthmus of the thyroid is cleared. This must be divided d. Levator Anguli Oris between artery forceps or displaced downwards. 4. What is the gland responsible for production of saliva at rest? A vertical incision is made in the trachea a. Parotid b. Sublingual c. Submandibular d. Pineal 5. What are the antagonizing or opposing muscles found around the area of the eyes responsible for the eyebrow shaping? a. Levator labii superioris alaeque nasi and Orbicularis Oris b. Frontalis and Nasalis c. Orbicularis oculi and Frontalis d. Levator labii superioris alaeque nasi and Nasalis 6. What is the pathology of the SCM where there is hypertrophy of said muscle? a. Frontalis b. Torticollis c. Sternocleidomastoid Syndrome Figure 66. Tracheostomy tube insertion. d. Mumps Typically, the tracheostomy tube is placed between the 2nd 7. It was noticed that the lymph nodes anterior to the and 3rd tracheal rings (below the thyroid and cricoid sternocleidomastoid muscle below the hyoid bone were swollen. cartilages). What level would you designate lymph nodes? a. 6 b. 5 J. HEIMLICH MANEUVER c. 3 Used to dislodge a foreign body obstruction in the airway. d. 2 8. Posterior to which tracheal ring is the tracheostomy tube typically inserted? a. 4th b. 3rd c. 2nd d. 1st 9. Thyroid gland is located in the following except? a. Thyroid cartilage b. Cricoid Cartilage c. Tracheal Cartilage d. Both B and C 10. Which has a Superior, Inferior, and Medial? Figure 67. Heimlich Maneuver. I. Thyroid Artery II. Thyroid Vein Give five back blows Give five abdominal thrusts a. I b. II c. Both I and II d. Neither I nor II 11. What bridges the left and right strap muscle? a. Isthmus b. Pyramidal Lobe ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 16 of 18  Y1B4M2L1: THE HEAD, FACE & NECK c. Midline Fascia d. Cricothyroid Muscle 12. Most important to be careful with during thyroidectomy? a. Arteries / veins b. Nerves c. Parathyroid d. Trachea 13. This type of suprahyoid bone starts from the middle of the mandible to the hyoid bone. a. Digastric b. Geniohyoid c. Stylohyoid d. Mylohyoid 14. All of the statements about the Hyoid Bone is correct EXCEPT: a. It is a floating bone as it does not have any attachment to other bones b. It determines our cervico-mental angle c. It pulls the muscles of the infrahyoid and suprahyoid muscles to form an angle d. Usually found at the point where the neck and the jaw meet Answers: 1D, 2D, 3A, 4C, 5C, 6B, 7A, 8C, 9A, 10B, 11C, 12B, 13B, 14C References: Snell, R.S. (2012). Clinical Anatomy by Regions (9th ed.) DAGITAB Batch Trans Head and Neck Lecture by Dr. Arik Delacruz- https://www.youtube.com/watch?v=LDYADRL9k2 ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 17 of 18  Y1B4M2L1: THE HEAD, FACE & NECK VI. APPENDIX Mastication Muscles (Snell’s Clinical Anatomy 10th ed) Scalp and Face Muscles (Snell’s Clinical Anatomy 10th ed) ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 18 of 18