The Larynx Flashcards
what is larynx suspended from?
hyoid bone via thyroid membrane
what is trachea suspended from?
cricoid cartilage of larynx
what are the 3 unpaired cartilage of larynx?
epiglottis
cricoid
thyroid
What 1/6 paired cartilage of larynx?
arytenoid
why does the larynx have intrinsic muscles?
for speech
how many laminae does thyroid cartilage have?
2 laminae with superior and inferior horns
what does the inferior horn articulate with?
cricoid cartilage at cricothyroid joints
What does the cricoid cartilage have?
anterior arch and posterior lamina
What does cricoid cartilage articulate with?
- thyroid cartilage so has lateral facets
- arytenoid so has superior facets
What does arytenoid cartilage articulate with?
superior aspect of cricoid lamina
what does the cricoarytenoid joint allow?
arytenoid to rotate
what shape is epiglottis cartilage?
leaf shaped
What is the thyrohyoid membrane?
runs length of superior border of thyroid cartilage and inserts into hyoid bone
What is quadrangular membrane?
runs from superior process of arytenoid cartilage to lateral edge of epiglottic cartilage
what is the vestibular ligament?
freen inferior edge of quad. membrane
- membranous core of vestibular folds
what does the cricothyroid membrane attach to?
- superior border of cricoid arch
- thyroid cartilage anteriorly
what is the upper membrane of the cricothyroid called?
free and thickenes= vocal ligament ,
what is the vocal ligament?
membranous core of true vocal cord
what is the origin of the cricothyroid muscle?
anterolateral aspect of cricoid arch
where does the cricothyroid muscle insert?
inferior horn and lower border of thyroid cartilage
what does the cricothyroid muscle do?
move cricoid arch and thyroid laminae
- pulls thyroid forward/down
what does cricothyroid muscle cause?
increase length in vocal folds (lower pitch) and tension so raises pitch
what innervates cricothyroid muscle?
external branch of superior laryngeal nerve
what is the origin of the thyroarytenoid muscle?
anterior deep surface of thyroid cartilage
where does the thyroarytenoid muscle insert?
superior process of arytenoid cartilage
what does the thyroarytenoid muscle do?
separate cricoid arch and thyroid laminae
what does thyroarytenoid muscle cause?
decrease in length of vocal folds (higher pitch) and tension so lower pitch
What innervates thyroarytenoid muscle?
recurrent laryngeal nerve (X)
what does the Transverse and Oblique interarytenoid muscles do?
move arytenoids medially
What innervates trans/oblique interarytenoid muscles?
recurrent laryngeal nerve (X)
What is the origin of lateral cricoarytenoid muscle
superolateral border of cricoid cartilage
where does lateral cricoarytenoid muscle insert?
muscular process of arytenoid cartilage
what does lateral cricoarytenoid muscle do?
medially rotates arytenoid cartilage so adduction of vocal folds
What innervates of lateral cricoarytenoid muscle?
recurrent laryngeal nerve (x)
What is the origin of posterior cricoarytenoid muscle
posterior surface of cricoid lamina
where does posterior cricoarytenoid muscle insert
muscular process of arytenoid cartilage
what does posterior cricoarytenoid muscle do?
laterally rotates arytenoid cartilage so abduction of vocal folds
What innervates posterior cricoarytenoid muscle?
recurrent laryngeal nerve (X)
why do we need abduction of folds?
for normal breathing
What does the VAGUS nerve do?
provide motor/sensory supply to all muscles of larynx
what are branches of vagus nerve?
superior and recurrent laryngeal branches
what does the superior laryngeal branch divide into?
internal and external laryngeal nerve
What does the recurrent laryngeal nerve innervate?
sensation is inferior to vocal folds and motor to all larynx muscles except cricothyroid
what does the external laryngeal nerve innervate?
motor supply to cricothyroid muscle
what does the internal laryngeal nerve innervate?
sensation superior to vocal folds
where is recurrent laryngeal nerve?
- arch beneath subclavian artery
- ascends in groove between trachea & oesophagus
- inferior border of inferior constrictor muscle of pharynx