Thyroid and Larynx Flashcards
Location of the thyroid
Deep to sternothyroid and sternohyoid muscles
at vertebral levels C5-T1
Isthmus anterior to the 2nd and 3rd tracheal rings
Arterial blood supply of the thyroid
Superior thyroid A: supplies the anterior-superior aspects of the gland
Inferior thyroid a: Supplies the posterior-inferior aspects of the gland
Thyroid ima artery: Found in 10 percent of people located anterior to the trachea
Veins of the thyroid
Superior, middle, and inferior thyroid veins form the thyroid plexus of veins
Thyroid relationships
Recurrent laryngeal nerves ascend in a groove between trachea and esophagus and they past deep to the posteromedial surface of the lateral lobes of the thyroid gland
ligaments bind thyroid gland to trachea and cricord cartilage of larynx
Organization and function of the Larynx
Located at vertebral levels C3-C6
Connected to the pharynx and trachea
Functions: Phonation and patent airway
Thyroid Cartilage
Located at C4 Laminae Laryngeal prominence (adams apple) Superior thyroid notch Superior and inferior thyroid horn
Cricoid cartilage
Located at C6
signet ring shaped
Laminae and arch
Thyrohyoid membrane
Aperture for the internal branch of superior laryngeal N and superior laryngeal A
Cricothyroid membrane
Lateral and medial cricothyroid membranes
cricothyrotomy
connect the crico cartilage and the thyroid cartilage
Arytenoid cartilage
Sits on top of the Cricord cartilage
Corniculate artilage sits on on top of the arytenoid cartilage
Laryngeal Spaces: Laryngeal cavity
Extends from the laryngeal inlet, through which it communicates with the laryngopharynx, to the inferior border of the cricoid cartilage
it is continuous with the trachea
Laryngeal Spaces: Laryngeal vestibule
Between the laryngeal inlet and the vestibular folds
Laryngeal Spaces: Laryngeal ventricle
Between the vestibular and vocal folds
Laryngeal Spaces: infraglottic cavity
Between the vocal folds and the inferior border of the cricoid cartilage
Laryngeal Spaces: Rima glottidis
Space between the vocal folds
Conus Elasticus
Provides structure for vocal ligaments
Vestibular folds
False vocal cords
Vocal Fold
Vocal cords
Cricothyroid Muscle
Orgin: Anterolateral part of cricoid cartilage
Insertion: Inferior margain and inferior horn of thyroid cartilage
Inn: External aryngeal Nerve (from CN X)
Stretches and tenses vocal ligament
Thyro-arytenoid Muscle
Orgin: Lower half of posterior aspect of angle of thyroid laminae and cricothyroid ligament
insertion: Anterolateral arytenoid surface
Inn: Inferior laryngeal nerve (from CN X)
Relaxes vocal ligament
Posterior Crico-arytenoid muscle
orgin: Posterior surface of lamina or cricoid cartilage
Insertion: Vocal process of arytenoid cartilage
inn: Inferior laryngeal N (from CN X)
ABducts vocal folds
Lateral Crico-arytenoid Muscle
Orgin: arch of cricoid cartilage
insertion: Vocal process of arytenoid cartilage
inn: Inferior laryngeal Nerve ( CN X)
Adducts vocal folds
Transverse and oblique arytenoids
orgin: One arytenoid cartilage
insertion: Contralateral arytenoid cartilage
inn: Inferior laryngeal Nerve (CN X)
Adduct arytenoid cartilages
Vocalis Muscle
Orgin: Lateral surfcae of vocal process of arytenoid cartilage
insertion: Ipsilateral vocal ligament
Inn: Inferior laryngeal nerve (CN X)
Relaxes posterior vocal ligament while maintaining tension of anterior part
What muscles are active during forced respiration
Posterior crico-arytenoid
so it can Abduct the vocal folds to increase the opening
What muscles are active during phonation
Lateral crico arytenoid
Transverse and oblique arytenoids
to keep the vocal folds opening closed ish
What muscles are active during whispering?
Lateral crico arytenoid and the oblique arytenoid
this makes a small opening at the bottom
Superior Laryngeal Artery
Accompanies internal branch of superior laryngeal Nerve
supplies the superior larynx above the vocal folds
Inferior laryngeal Artery
Supplies the inferior Larynx below the vocal folds
Accompanies the inferior Laryngeal Nerve
Superior Laryngeal nerve branches into the internal and external branches:
Internal branch of superior laryngeal Nerve is sensory
innervates the sensory above the vocal folds
External branch of the superior laryngeal Nerve is motor and innervates the cricothyroid muscle
Inferior Laryngeal Nerve
Terminal branch of recurrent laryngeal nerve
Sensory and motor
innervates all intrinsic muscles of the larynx except for cricothyroid
sensory below the vocal folds
