Lecture 31 DA Flashcards
What are the upper and lower boundaries of the larynx?
From the epiglottis to C6, lower border of cricoid cartilage.
What makes up the laryngeal skeleton?
Hyoid bone
Thyroid cartilage
Cricoid cartilage
Does the laryngeal skeleton have a posterior border?
Only the cricoid cartilage, hyoid and thyroid bone/cartilage are open.
What is formed by the laryngeal skeleton posteriorly?
Laryngeal inlet.
What is the angle of the thyroid?
Adam’s apple.
What is the lamina of the thyroid cartilage?
It has an anterior and posterior lamina.
Where are the horns of the thyroid cartilage?
It has four total, two superiorly, two inferiorly.
How does the thyroid cartilage articulate with the cricoid cartilage?
Via the inferior horns.
Is the cricoid cartilage bridged posteriorly by trachealis?
No, it forms a complete circle.
What is the shape of the cricoid cartilage?
Short anterior arch and tall posterior lamina.
Looks like a signet ring.
Where are the aratenoid cartilages found, and what shape are they?
Posteriorly on the cricoid cartilage and are pyramid shaped.
What are the two processes of the aratenoid cartilage?
Vocal process medially and muscular process laterally.
How does aratenoid cartilage mediate phonation?
They can swivel in and out of the cricoid, as well as slide towards and away from each other.
What is found between hyoid bone and thyroid cartilage?
Thyrohyoid membrane. Has deficiencies to allow vessels to pass.
What is cound between cricoid and thyroid carilages?
Cricothyroid membane (also ligament), is continuous.
Where does the epiglottic artilage attach?
To the angle of thyroid posteriorly.
Where do vocal ligaments attach?
From arytenoid cartilage to the angle of thyroid posteriorly.
Where does the quadratic membrane attach?
From the arytenoid cartilage to the superior border of the epiglottic cartilage. It is complete.
What is the vestibular ligament?
Inferior, thickened, free edge of the quadratic membrane.
What is the aryepiglottic ligament?
Superior, thickened, free edge of the quadratic membrane.
What is the aryepiglottic fold?
Mucosa membrane over the aryepiglottic ligament.
What is the vestibular fold?
Mucosa membrane over the vestibular ligament.
What is the vocal fold?
Vocal cords. Mucosa membrane over the vocal ligaments.
What is the false vocal cord, and what does it do?
Vestibular fold. Doesn’t produce sound in humans. Protects true vocal folds.
What is special about the vestibular fold in cats?
They have a very large one which allows them to purr. Meows come from the vocal fold.
What reflexes are found in the larynx?
Strong gag and cough reflexes.
What happens to the vocal ligaments during phonation?
Adduction.
What happens to the vocal ligaments during breathing?
Abduction.
What is the rima glottis?
Space between vocal ligaments and directly under it.
Where does the cricothyroid muscle attach, and what does it do to the fold when contracting?
Posterior surface of the cricoid to the thyroid. It lengthens the fold.
Where does the thyroarytenoid muscle attach, and what does it do to the fold when contracting?
Posterior angle of the thyroid to the arytenoid, along the vocal ligament. Relaxes the fold.
Where does the vocalis muscle attach, and what does it do to the fold when contracting?
Runs along the vocal ligament. Relaxes the fold.
Where does the lateral cricoarytenoid muscle attach, and what does it do to the fold when contracting?
From arytenoid laterally down to cricoid anteroinferiorly. Adducts the fold.
Where does the posterior cricoarytenoid muscle attach, and what does it do to the fold when contracting?
From arytenoid posteriorly down to cricoid medioinferiorly. Abducts the fold.
Where do the transverse and oblique cricoarytenoid muscle attach, and what does it do to the fold when contracting?
Between the two arytenoids. Closes rima glottis. Brings the folds together.
What nerve innervates the larynx from above and what do its branches innervate?
Superior laryngeal (vagus)
Internal laryngeal - sensory to mucosa
External laryngeal - cricothyroid muscle
What nerve innervates the larynx from above and what do its branches innervate?
Recurrent laryngeal (vagus) Inferior laryngeal - all muscles except cricothyroid
What happens when you damage the recurrent laryngeal nerve?
Hoarse voice and stridor.
What is stridor?
The sound of excessive effort needed to talk, as more air is needed to vibrate folds.
Where is the thyroid gland found?
Inferior to the thyroid cartilage.
What supplies blood to the larynx from above and below?
Superior and inferior laryngeal vessels.
Why are blood vessels being directly superficial to the trachea so significant?
If you do an emergency airway tracheotomy, blood can get into the lungs and drown the patient.
Where is the best place to do an emergency airway?
Cricothyroid membrane puncture.
Where is tracheotomy usually done?
Only in a surgical setting.
What is an intubation, what what position should the head and vocal cords be in?
Artificial ventilation. Hyperextend the head. Vocal folds must be relxed to avoid damage.
