Anatomy: Larynx Flashcards
Functions of the larynx
- Part of the air passages
- Acts as a sphincter
- Sound production
How does the larynx function as part of the air passages?
Links pharynx above to the trachea below
How does the larynx act as a sphincter?
Prevents passage of solids and liquids from the pharynx to the air passages below
How does the larynx function in sound production?
- Acts as the organ of phonation
- Controls the expulsion of air from the lungs to produce sounds.
Where is the larynx located?
- Anterior neck
- Opposite cervical vertebrae C4-C6
What does thyroid mean in Greek?
Probably not necessary, but why not?
Oblong Shield
What does the skeleton of the larynx consist of?
- 3 unpaired cartilages
- 3 pairs of cartilages
Unpaired cartilages
- Thyroid (large one)
- Cricoid
- Epiglottis
Paired cartilages
- Arytenoid
- Corniculate
- Cuneiform
Position of larger portion of cricoid cartilage vs smaller portion?
The larger portion of the cricoid cartilage faces behind and the smaller portion in front
Composed of 2 plate-like laminae that fuse anteriorly in the midline to form the LARYNGEAL PROMINENCE (ADAM’S APPLE)
Thyroid Cartilage
What makes up the laryngeal prominence?
Thyroid cartilage composed of 2 plate-like laminae that fuse anteriorly in the midline
Where is the superior laryngeal notch located?
Above the laryngeal prominence
It’s a v-shaped notch
Name of the posterior border of each lamina that projects superiorly and inferiorly
- superior horn
- inferior horn
What do the inferior horns articulate with?
**UNDERLINED
Cricoid cartilage (unpaired)
A ridge on the lateral aspect of the thyroid cartilage
Oblique line
What does the oblique line give attachment to?
**UNDERLINED
- Sternothyroid muscle
- Thyrohyoid muscle
- Inferior pharyngeal constrictor muscle
Located inferior to the thyroid cartilage; SMALL ARTICULAR FACET at the junction of the arch and lamina ARTICULATES WITH THE INFERIOR HORN OF THE THYROID CARTILAGE
Cricoid Cartilage (unpaired)
What does the cricoid cartilage look like?
*Underlined
- SIGNET RING*
- Narrow arch anterior
- Wide lamina posterior
Superior border of the lamina of the cricoid cartilage has what?
2 facets for articulation with the bases of the arytenoid cartilages
What/where is the inferior border of the cricoid cartilage?
*UNDERLINED
- Horizontal
- Marks boundary between larynx and trachea
- Connected to the first tracheal cartilage by the CRICOTRACHEAL LIGAMENT
Spoon-shaped plate of elastic cartilage
Epiglottis (unpaired)
Features of the superior end of the epiglottis
- Broad
- Free
Features of the inferior end of the epiglottis
- Narrow (stalk)
- Attached by thyroepiglottic ligament to the angle formed by the 2 laminae of thyroid cartilage
Attachment of the ANTERIOR end of the epiglottis
*UNDERLINED
Attached to the body of the hyoid by the HYOEPIGLOTTIC LIGAMENT
2 PYRAMIDAL CARTILAGES located on each side of the superior border of the cricoid lamina
**IMPORTANT ONES
ARYTENOID CARTILAGES** (paired)
What is the vocal process for, and how is it directed?
*UNDERLINED
- Directed anteriorly
- GIVES ATTACHMENT TO THE VOCAL LIGAMENT
“Business end of sound production”
What is the muscular process for, and how is it directed?
*UNDERLINED
- Directed laterally
- GIVES ATTACHMENT TO THE POSTERIOR AND LATERAL CRICOARYTENOID MUSCLES
SYNOVIAL JOINT between the articular facet on the lateral aspect of cricoid cartilage and inferior horn of thyroid cartilage
Cricothyroid Joint
What does the right and left joints working together allow for?
*UNDERLINED
THYROID CARTILAGE TO TILT FORWARD AND BACKWARD ON CRICOID CARTILAGE (VISOR-LIKE MOVEMENT)
Synovial joint between articular facet on superior border of cricoid lamina and base of arytenoid cartilages
Cricoarytenoid Joint
What does the cricoarytenoid joint allow for?
- Rotation of the arytenoid around the vertical axis
- Gliding of arytenoid anteroposterior and medial-to-lateral
Membrane and ligaments of the Larynx
- Membrane:
- -Thyrohyoid membrane
- Ligaments:
- -Cricotracheal ligament
- -Hyoepiglottic ligament
- -Thyroepiglottic ligament
What is the job of the thyrohyoid membrane in the larynx?
- Suspends larynx from the hyoid bone
- Connects the body and greater horns of the hyoid bone to the upper border and superior horns of the thyroid cartilage
What is the job of the cricotracheal ligament in the larynx?
Connects inferior border of cricoid cartilage to the first tracheal cartilage
What is the job of the hyoepiglottic ligament in the larynx?
Attaches the epiglottis to the hyoid bone
What is the job of the thyroepiglottic ligament in the larynx?
Attaches the epiglottis to the thyroid cartilage
What is continuous with the mucosa of the pharynx and the trachea?
Laryngeal mucosa
Opening into the larynx
Laryngeal inlet
The laryngeal inlet allows communication between which 2 structures?
- Laryngopharynx
- Larynx
Placement of the laryngeal inlet
- Obliquely placed
- Plane passes posteriorly and inferiorly from the epiglottis to the arytenoid cartilages
Boundaries of the laryngeal inlet
- Anterior: Superior border of epiglottis
- Lateral: Aryepiglottic fold
- Posterior: Interarytenoid notch
What does the aryepiglottic fold contain?
- Corniculate cartilages
- Cuneiform cartilages
–both in its posterior part
Upper part of the laryngeal cavity inside the larynx
Laryngeal vestibule
What does the laryngeal vestibule extend from?
From the laryngeal inlet, superiorly, to a pair of mucosa folds (vestibular folds), inferiorly
Space between the right and left vestibular folds
*UNDERLINED
Rima vestibuli
Also known as false folds
(Rima = passageway)
SPACE BETWEEN VESTIBULAR AND VOCAL FOLDS ON EACH SIDE
*UNDERLINED
LARYNGEAL VENTRICLE
Shape of laryngeal ventricle when viewed from the laryngeal cavity
Spindle-shaped interval
Which part of the laryngeal ventricle extends upward for a variable distance, lateral to the vestibular folds?
*UNDERLINED
Laryngeal Saccule
What does the laryngeal ventricle’s mucosa contain, and what are they a source of?
- Contains numerous mucous glands
- Source of lubricating mucus for vocal folds
Prominent, shelf-like folds of mucosa that contain the vocal ligaments
*BOLDED
VOCAL FOLDS
The space between the right and left vocal folds
*UNDERLINED
RIMA GLOTTIDIS
2 parts of the Rima Glottidis
- Intermembranous (anterior 3/5)
- Intercartilaginous (posterior 2/5)
Comparing the rima glottidis and the rima vestibuli, which one is narrower than the other?
Rima glottidis
What varies the shape and width of the rima glottidis?
**UNDERLINDED & STARRED
Movements of vocal folds and arytenoid cartilages
Muscles of the larynx
- Extrinsic muscles
- Intrinsic muscles
ORIGINATION & INSERTION OF THE EXTRINSIC MUSCLES OF THE LARYNX
*UNDERLINED
- Origination: Outside the larynx
- Insertion: Into the Larynx or Hyoid bone
Function of extrinsic muscles of the larynx
Move larynx as a whole
- Elevation
- Depression
Extrinsic muscles of the larynx (elevators and depressors)
Elevators (pull larynx upward)
- Suprahyoid muscles
- Longitudinal pharyngeal muscles
Depressors (push larynx downward)
-Infrahoid muscles
ORIGINATION AND INSERTION OF INTRINSIC MUSCLES OF THE LARYNX
*UNDERLINED
- Origination: within larynx
- Insertion: within larynx
Function of intrinsic muscles of the larynx
Capable of moving individual laryngeal cartilages (especially the arytenoid)
