Thyroid/Larynx S2M1

  1. What are the three cervical viscera layers of the neck and their contents
    • Endocrine - Thyroid and Parathyroid glands
    • Respiratory - Larynx and Trachea
    • Alimentary - Pharynx and Esophagus
  2. What are the layers on the thyroid gland
    • False capsule
    • True capsule
    • The plane of surgery is between these two with the thyroid venous plexus beneath
  3. Where is the thyroid gland in respect to muscles and the vertebrae
    It lies deep to the Sternothyroid and Sternohyoid between levels C5-T1
  4. What are the lobes in the thyroid gland
    • Isthmus
    • Pyramidal
    • Right lobe
    • Left Lobe
  5. Where does the nerve supply come from for the thyroid gland
    Superior, Middle, and Inferior cervical sympathetic ganglion (All are vasomotor)
  6. What is the arterial supply to the thyroid gland
    • Inferior thyroid (branched from thyrocervical trunk)
    • Superior thyroid (branch from external carotid)
    • One on each side
  7. What is the venous drainage from the thyroid gland
    • Superior thyroid
    • Middle thyroid
    • Inferior thyroid (branch of left brachiocephalic)
  8. Why is the left brachiocephalic more likely to get a metastases from the thyroid gland
    It has two venous from the gland draining into it (Left middle, and Inferior thyroid)
  9. Where are the parathyroid glands
    Posterior to the trachea and external to the true capsule but inside the false capsule of the thyroid gland
  10. What vessel is in danger of being damaged in a tracheostomy
    Thyroid ima artery
  11. The pyramidal lobe and band of the thyroid gland develop from
    Remnants of the epithelium and connective tissue of the thyroglossal duct
  12. Median fistula vs lateral fistula and cyst
    • Median fistula is a cyst on the thyroid in the midline of the neck and will move upward upon swallowing
    • Lateral fistula is simply lateral to this
  13. What must by carefully identified and kept in tack in removing a cyst from the thyroid
    Hypoglossal nerves
  14. How can it be determined whether a cyst is on the thyroglossal duct or the thyroid gland
    If the cyst moves upon protrusion of the tongue it is in the thyroglossal duct, if it moves when swallowing it is on the thyroid
  15. Development of the thyroid begins where
    At the foramen cecum and then descends down the thyroglossal duct
  16. Thyroid glandular tissue and accessory tissue can be found possibly where
    Anywhere along the path of the embryonic thyroglossal duct
  17. Ectopic thyroid gland
    • Thyroid gland in an abnormal location, often high in the median plane of the neck
    • Can mistakenly by taken for a accessory thyroid and removed causing hypothyroidism
  18. Goiter
    • A non-neoplastic enlargement of the thyroid gland other then the variable enlargement that may occur during menstruation or pregnancy
    • Caused by a lack of iodine
  19. What secondary conditions can goiter cause
    Compression of the esophagous, trachea, and recurrent laryngeal nerves causing difficulty swallowing and hoarseness of voice
  20. What is commonly done in a total thyroidectomy
    The posterior part of each lobe is left to protect the recurrent and superior laryngeal nerve
  21. What happens if there is inadvertent removal of the parathyroid glands
    Tetany (muscle twitches and cramps)
  22. What is the role of the larynx and where is it located
    • Organ of phonation
    • Sphincter guards respiratory tract
    • Connects Oropharynx with trachea
    • C3-C6
  23. What are the three paired and unpaired cartilages of the larynx
    • Paired - Arytenoids, Corniculate, Cuneiform
    • Unpaired - Epiglottis, Thyroid, Cricoid
  24. What is considered the most important cartilage of the larynx and why
    • Arytenoid
    • Contains vocal ligament
  25. What is the space between the vocal folds
    Rima Glottidis
  26. What is the purpose of the vestibular ligaments
    (False vocal cords) protects the true vocal cords
  27. Air goes through what spaces on the way to the lungs from the epiglottis
    • Laryngeal inlet
    • Vestibule
    • Ventricle
    • Vocal fold
    • Infraglottic space
    • Trachea
  28. What is the space called between the two vestibular folds
    Rima vestibulli
  29. How are the vocal folds positioned in Normal respiration, Whispering, Forced expiration, and Phonation
    • Halfway open
    • Very small space
    • Wide open
    • Closed
  30. What is the role of the cricothyroid
    It tenses the vocal ligament
  31. What is the role of the transverse arytenoids
    Adducts the vocal folds
  32. What is the role of the lateral cricoarytenoid
    Adducts vocal folds
  33. What is the role of the Thyroarytenoid and vocalis
    Relaxes the vocal ligament
  34. What is the role of the Oblique arytenoids
    Adducts vocal folds
  35. What is the role of the Posterior cricoarytenoid
    Abducts vocal folds and is also important for breathing opening up the channel
  36. What happens if both of the recurrent laryngeal nerves are damaged
    There is respiratory obstruction due to the relaxing of the vocal folds
  37. What does the recurrent laryngeal nerve innervate
    All intrinsic muscles of the larynx accept cricothyroid
  38. What does the internal laryngeal nerve innervate
    Mucous membrane above the vocal cord and taste buds on the epiglottis
  39. What results in a lesion to the internal laryngeal nerve
    Loss of sensation to above the vocal cord and loss of taste to the epiglottis
  40. What does the external laryngeal nerve innervate and what would result in its lesion
    • Cricothyroid and inferior pharyngeal constrictor
    • Fatigued voice and weak hoarseness
  41. Where do fish bones often get stuck
    Periform fossa
  42. Tracheostomy
    Incision into infraglottic cavity (between 1-2 or 2-4 tracheal rings) to establish and airway for patients with upper airway obstruction
  43. Cricothyrotomy
    Incision made through the median cricothyroid ligament to establish an emergency airway
Card Set
Thyroid/Larynx S2M1