The larynx Flashcards
What is the larynx?
Part of the respiratory tract which is reinforced with cartilages which articulate with each other at synovial joints and can be moved with precision
What are the functions of the larynx?
- protection of the lower respiratory tract to prevent inhalation of food or liquids during swallowing or vomiting
- phonation by vibration of vocal folds
What are the key structures in the laryngeal skeleton?
- hyoid bone
- thyroid cartilage
- cricoid cartilage
- arytenoid cartilages
- epiglottis
What is the epiglottis?
Cartilage which moves over the opening of the larynx to protect the airway
How is the epiglottis connected to the thyroid cartilage?
By the thyroepiglottic ligament
How are the hyoid bone and thyroid cartilage connected?
by the thyrohyoid membrane and thyrohyoid muscle
What are the features of the thyroid cartilage?
- large lamina on both sides
- laryngeal prominence
- open posteriorly
- 2 superior horns (each side) which connect to hyoid by thyrohyoid membrane
- 2 inferior horns (each side) connect to cricoid
What are the features of the cricoid?
- signet in shape
- only complete ring of cartilage in respiratory system
- attached to thyroid by cricothyroid joint
- articulates with cricoid cartilage
Where are the arytenoids?
on top of the cricoid
What are the cricoarytenoid joints?
synovial joints between the arytenoids and the cricoid lamina
Where do the vocal folds attach?
- anteriorly to thyroid cartilage
- posteriorly to the vocal processes of the arytenoids
What movements are possible at each cricoarytenoid joint?
- sliding apart/together
- rotation about a vertical axis
- tilting forwards or backwards
What are the effects of the sliding motion of the arytenoids?
- slide medially = adduction (close) of vocal cords
- slide laterally = abduction (open) of vocal folds
What are the effects of the rotation movement of the arytenoids?
- rotate inwards = adduction (close) of vocal folds
- rotation outwards = abduction (open) of vocal folds
What are the effects of the tilting movement of the arytenoids?
- tilting backwards = inc length and tension, dec thickness
- tilting forwards = dec length and tension, inc thickness