Laryngeal Framework Flashcards
Larynx
Forms the border between the upper (pharynx - oral/nasal) and lower (trachea, lungs, etc.) respiratory tracts
What is it made of?
Musculo-cartilaginous (made of muscle and cartilage) structure located at the superior end of the trachea
Bound superiorly by the hyoid bone and inferiorly by the cricoid cartilage
Laryngeal Framework Consists of
1 Bone, 3 unpaired cartilages, and 3 paired cartilages
1) Hyoid Bone (1)
2) Thyroid Cartilage (1)
3) Cricoid Cartilage (1)
4) Arytenoid Cartilage (2)
5) Corniculate Cartilages (2)
6) Cuneiform Cartilages (2)
7) Epiglottis (elastic cartilage) (1)
Meaning of biological functions
The larynx has biological (protective/life sustaining) and non-biological (voice production) functions
Biological are primary. That means that protection of the larynx an) and airway (lungs) will always come first.
Biological functions of larynx
1) Prevent foreign material from entering the lungs; and
2) Expel foreign substances that attempt to enter the trachea/lungs
Expel: coughing, throat clearing
Non-biological function of larynx
Voice production or phonation
Non-biological functions are also called OVERLAID FUNCTIONS. This means they are a 2nd function and not life sustaining
The Hyoid Bone
Unpaired bone
Only bone in larynx
U-shaped
Open posteriorly
3 Functions of hyoid bone
1) Suspends the larynx
2) Serves as a point of attachment for some extrinsic laryngeal muscles [originate outside of the hyoid bone] + inferior attachment for most of the tongue musculature
3) supports the root of the tongue
3 Parts of Hyoid Bone
1) Corpus or Body
2) Lesser Horns or Cornu (2)
3) Greater Horns or Cornu (2)
Thyroid Cartilage
Unpaired and the largest of the laryngeal Cartilages
Thyroid cartilage, plates, etc.
Thyroid has a PROMINENT ANTERIOR SURFACE made up of 2 plates called
1) Thyroid Laminae
2) Thyroid Angle
The superior-most portion of the thyroid angle is the THYROID NOTCH
You can also call it the SUPERIOR THYROID NOTCH
Superior-most portion of the thyroid angle
thyroid notch or superior thyroid notch
Horns of cartilage
On posterior aspect of the thyroid cartilage, there are two sets of cornu or horns
INFERIOR CORNU
SUPERIOR CORNU
INFERIOR CORNU
project inferiorly to articulate with the cricoid cartilage
Superior cornu
project superiorly to articulate with the hyoid bone
Thyroid Cartilage - oblique line
Can be found on the lateral, superficial aspect of the thyroid laminae
The oblique line serves as a point of attachment for some laryngeal MUSCLES
CRICOID CARTILAGE
Unpaired
Most INFERIOR portion of the larynx
Taller posteriorly than it is anteriorly, + shaped like a signet ring
Superior to the 1st tracheal ring
Where do the arytenoid cartilages articulate?
AC articulates on the superior-most aspect of the CRICOID CARTILAGE.
Superior surface is called the POSTERIOR QUADRATE LAMINA
Posterior Quadrate Lamina
Superior surface of the cricoid cartilage where the arytenoid cartilages articulate with the cricoid cartilages
Thyroid and Cricoid Cartilage Articulation
On the lateral surfaces of the cricoid cartilage are the articular FACETS that mark the point of articulation for the inferior horns of the thyroid cartilage
INFERIOR CORNU articulate with the cricoid cartilage
Arytenoid Cartilages (harry potter sorting hats)
PAIRED
Articulate with the cricoid cartilage on the SUPERIOR portion of the POSTERIOR QUADRATE LAMINA
pyramid-shaped
each cartilage has 2 PROCESSES + 4 SURFACES
primary function of the arytenoid cartilages?
Allows movement of the vocal folds for phonation/voicing and swallowing
Where do the corniculate cartilages rest?
Apex (highest point) of the arytenoid
they look like smaller harry potter sorting hats
What are the 2 processes of Arytenoid Cartilages?
1) VOCAL PROCESS
2) MUSCULAR PROCESS
Arytenoid Cartilages - Vocal Process
Projects anteriorly towards the thyroid notch
The POSTERIOR portion of the VOCAL FOLDS are attached to this process
Arytenoid Cartilages - Muscular Process
Projects laterally on the arytenoid cartilage
Point of attachment for muscles that abduct (open) + adduct (close) the vocal folds
Epiglottis
Unpaired
Leaf-shaped cartilage
Arises from the inner surface of the angle of the thyroid cartilage, just below the notch
Projects UPWARD beyond the larynx and ABOVE the hyoid bone, + is attached to the ROOT of the tongue
Sides of the epiglottis are joined with the arytenoid cartilages via the ARYEPIGLOTTIC FOLDS
Aryepiglottic Folds
Produced by the membranous lining overlapping muscle and connective tissue
Extend from the apex of the arytenoids to the lateral margins of the epiglottis
Cuneiform Cartilages
Small cartilages that are embedded in the aryepiglottic folds
FUNCTION: serve to SUPPORT the membranous laryngeal covering
