The Head, Face & Neck Anatomy PDF

Y1B4M2L1 THE HEAD, FACE & NECK ● Three Veins ○ Superior thyroid vein ○ Middle thyroid vein ○ Inferior thyroid vein Figure 46. Location of RLN at the back of thyroid gland and tracheal groove. EXTERNAL BRANCH OF THE SUPERIOR LARYNGEAL NERVE EBSLN Figure 44. Three veins you need to be careful with...

Y1B4M2L1 THE HEAD, FACE & NECK ● Three Veins ○ Superior thyroid vein ○ Middle thyroid vein ○ Inferior thyroid vein Figure 46. Location of RLN at the back of thyroid gland and tracheal groove. EXTERNAL BRANCH OF THE SUPERIOR LARYNGEAL NERVE EBSLN Figure 44. Three veins you need to be careful with during thyroidectomy. NERVES RECURRENT LARYNGEAL NERVE RLN ● Has two components: Left and Right RLN ● Found just at the back of the thyroid gland and tracheal groove Figure 45 . ● Function: Control of voice box ○ Loss of RLN will result to hoarseness ● Has two components: Left and Right EBSLN ○ Located near the upper pole of each thyroid lobes and inserts into the cricothyroid muscle ● Functions: ○ Innervates the cricothyroid muscle ○ Controls the pitch of voice → Loss will result to inability to reach high notes Lecturerʼs Notes: ● Nerve is sometimes called Amelita Galli-Curci nerve ● Amelita Galli-Curci was an opera singer who lost her high notes after her thyroidectomy since her EBSLN was cut. Figure 47. Location of EBSLN PARATHYROIDS Figure 45. Left and right RLN ● 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 ● Parathyroid hormone PTH - regulates calcium and phosphate metabolism ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 11 of 17 Y1B4M2L1 THE HEAD, FACE & NECK Figure 48. Location of parathyroid glands. Figure 51. Carotid Sheath Figure 49. Actual view of parathyroid glands. Lecturerʼs Notes: ● During thyroidectomy, sometimes you need to preserve at least one or two PT gland since complete loss of it will result to hypocalcemia which will result to cramps, muscle spasms, and paresthesia (nerve numbness) CAROTID SHEATH ● 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: digestion, heart and respiratory rate, etc. → It branches out to the recurrent laryngeal nerve and the superior laryngeal nerve 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 to air pockets on the neck (like sounds of popped bubble wraps) called subcutaneous emphysema ESOPHAGUS ● Location: ○ Just at the back of the trachea ○ Starts the C5 6 vertebrae at the level of the cricoid cartilage ● Function: Muscular tube which allows food to pass through going into the stomach ● Damage, cut, or perforation of esophagus will lead to leakage of saliva and food into the neck which will cause deep-neck infection 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 50. Components of the Carotid Sheath ● Layers in performing surgery of the thyroid gland: ○ Skin ○ Platysma ○ Strap muscles ○ Thyroid gland ○ Cut off veins & arteries ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 12 of 17 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 52. Thyroidectomy H. LYMPH NODES LYMPH NODE REMOVAL POST THYROIDECTOMY ● Remove 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 53. Thyroid cancer (invasive tumor) that may spread (metastasize) through the neighboring lymph nodes. Figure 55. Lymph node levels 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 ○ Posterior neck ● Level 6 ○ In front of SCM and below hyoid LYMPH NODES OF THE NECK ● The neck has abundant lymph nodes; appear like “beans” scattered all over the neck. ● Functions: ○ Lymphatic system: → Filtration → Immunity ● Cancers can spread through these lymph channels and gets trapped in these lymph nodes Figure 56. Case of neck (thyroid) mass with lymph node enlargement. The mass is indicated by the red circle while the lymph nodes are indicated by the yellow arrows Figure 54. Lymph nodes of the neck ● Based on the figure above, probably, Level 3 lymph nodes are affected. ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 13 of 17 Y1B4M2L1 THE HEAD, FACE & 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, underlying problems may be present. Figure 60. Superficial lymph drainage of the head and neck. Snellʼs, 9th Ed.) Figure 58. Flow of lymph from the head, face, and neck. Figure 61. Superficial lymphatic system in the head and neck Grayʼs 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 Figure 59. Lymph drainage of the head and neck SUPERFICIAL LYMPH NODES ● Superficial lymph nodes – lie along the external jugular vein superficial to the sternocleidomastoid muscle ○ Receive lymph vessels from the occipital and mastoid lymph nodes ○ Drain into the deep cervical lymph nodes 8 00 PM CASE SCENARIO – McDonaldʼs: ● Finished surgery at 7 00 PM. waited for the patient to wake up before heading home. Passed by McDonaldʼs 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 patient to breathe in the presence of an upper airway obstruction ● Normal direction of air during inhalation: nose → larynx → trachea → lungs ● Upper airway obstruction – choking or obstruction (e.g. food, foreign materials, cancer) above the trachea ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 14 of 17 Y1B4M2L1 THE HEAD, FACE & NECK TRACHEOSTOMY PROCEDURE Figure 65. Tracheostomy procedure. Figure 62. Upper airway obstruction blocking airflow to and from the lungs ● Emergency tracheostomy – bypasses the obstruction and allows the patient to breathe ● The incision is placed midway between the cricoid cartilage and the suprasternal notch. ● The investing layer of fascia covering the pretracheal muscles (strap muscles) is exposed. ● The isthmus of the thyroid is cleared. This must be divided between artery forceps or displaced downwards. ● A vertical incision is made in the trachea Figure 66. Tracheostomy tube insertion. Figure 63. Tracheostomy tube placed inside the trachea REVIEW THE LAYERS OF THE NECK ● Typically, the tracheostomy tube is placed between the 2nd and 3rd tracheal rings (below the thyroid and cricoid cartilages). J. HEIMLICH MANEUVER ● Used to dislodge a foreign body obstruction in the airway. Figure 67. Heimlich Maneuver. Figure 64. Dissection of the neck. ● Structures before the trachea (from most superficial): ○ Skin ○ Platysma ○ Strap muscles (left and right) ○ Thyroid ○ Trachea ● Give five back blows ● Give five abdominal thrusts ARANAS, BORRES, BUNGAY, GABATA, LABRADOR, PANIZA, REA, TUPAZ, VICTORIANO, VILLAVICENCIO | MG 8 15 of 17