Anatomy of the larynx Flashcards
What are the main functions of the larynx?
- Airway protection
- Ventilation - its open when air moves in and out of lungs
- Role in cough reflex - vocal cords are brought together to build up pressure in thorax before coughing
- Produces sound (phonation)
Why does food not go into the airway when eating and drinking?
The larynx
What is the larynx?
A tube created by ligaments, membranes, cartilages and muscles
Where is the anatomical location of the larynx?
It is suspended from and lies below the hyoid by the thyrohyoid membrane
-every time hyoid bone moves, the larynx moves
Where does the larynx start and end?
Starts at the laryngeal inlet and ends at the cricoid cartilage at about C6
What does the larynx continue as?
The trachea
What forms the opening (laryngeal inlet) to the larynx?
- Elastic cartilage (epiglottis)
- quadrangualr membrane (runs from edges of epiglottis across to the arytenoid cartilage)
- arytenoid cratilages at the back connected by muscle
What gives ride to the vocal folds?
Inferior border of the quadrangular membrane
Superior border of the cricothyroid membrane
What are the pairs of vocal cords?
Vestibular ligament forms the false vocal cords and the vocal ligament forms the true vocal cords
What vocal cords are responsible for phonation?
The true vocal cords as they move - the false ones are fixed
What is the saccule?
between the vestibular and vocal folds is a small ventricle that leads laterally and upwards into the saccule and contains mucous glands that keep the true vocal cords moist
What type of epithelium lines the larynx?
Psudostratified ciliated columnar epithelium - with goblet cells
What are you true vocal cords lined with?
Stratified squamous - not pseudostratified ciliated columnar
What are you true vocal cords lined with?
Stratified squamous - not pseudostratified ciliated columnar
What are the 2 main actions of intrinsic laryngeal muscles?
- alter the size and shape fo the laryngeal inlet
- alter the tension and position of the vocal cords
What happens to the vocal cords in coughing?
The vocal cords are brought very close together in the midline and adduct to build up thoracic pressure before they snap open to allowing air to move
When else will the vocal cords be adducted?
During speech
What happens in swallowing?
Laryngeal inlet and vocal cords close to protect the respiratory tract
What happens in inspiration and expiration?
Open vocal cords and laryngeal inlet to allow movement of air
What does the posterior cricoarytenoid muscle do?
It. Is the only intrinsic muscle that abducts the vocal cord and widen the glottis
How is the gap alteration between the vocal cords achieved?
Intrinsic muscles move cartilages relative to one another
- arytenoids position on cricoid determines the position of the true vocal cords
What are the intrinsic muscles of the larynx innervated by?
The recurrent laryngeal nerve of vagus (CNX)
What nerve innervates the cricothyroid muscle?
external branch of superior laryngeal nerve (still innervated by CNX just a different branch)
What movements of the vocal cords allow phonation?
TheVC adduct to allow expired air to force through and the VC vibration creates sounds waves
