Larynx Flashcards
What suspends the Larynx from the hyoid bone?
Thyrohyoid Membrane
T or F: the hyoid is not part of the larynx
True
What is the role does the hyoid play in laryngeal function?
- All of the muscles attached to the hyoid elevate or depress the larynx
**Important action during swallowing
What are the 3 large unparied cartilages of the larynx?
- Thyroid
- Cricoid
- Epiglottis
What are the 3 smaller cartilages that are PAIRED in the larynx?
- Arytenoids
- Corniculate
- Cuneiform
What nerve provides both motor and sensory innervation to the larynx?
Vagus Nerve (X)
What direction do the lamina and arch of the cricoid cartilage face?
Arch of the Cricoid Cartilage - Anterior (much more narrow)
Lamina of the Cricoid Cartilage - Posterior
What cartilage articulates with the cricoid cartilage on the posteriorlateral surface of the cricoid lamina (wide posterior part)?
- Artenoid Cartilages
What does the lateral side of the cricoid lamina (wide posterior part) articulate with?
- Medial Surface of Inferior Horn of the Thyroid Cartilage
What is formed by the fusion of the TWO laminae that make up the thyroid cartilage?
- Laryngeal Prominence (adam’s apple)
**More acute in men (90º) and less acute in women (120º)
What separates the two laminae in the center of the thyroid cartilage above the laryngeal prominence?
- Superior Thyroid Notch
What is formed as elongations of the thryoid cartilage at the posterior aspect of the laminae?
- Superior and Inferior Horns
What does the inferior horn of the thyroid cartilage articulate with?
Cricoid
*medial aspect of horn on lateral aspect of cricoid
What connects the Posterior end of the Greater horn of the thyroid cartilage to the hyoid bone?
Lateral Thryohyoid ligament
What is formed at the inferior aspect of the oblique line of the thyroid cartilage?
- Superior and Inferior Thryoid Tubercle
What does the Thryo-epiglottic ligament attach the thryoid to the epiglottis?
- Attaches thin (stem) of the epiglottis to the ANTERIOR part of epiglottis between the Thryoid Prominence and they inferior notch
What do the Apex and Base of the Arytenoid Cartilages articulate with?
Apex:
Coriniculate Cartilage
Base: Cricoid cartilage (on superiolateral facets)
What is the job of the corniculate and cuneiform cartilages?
Corniculate:
- Make the arytenoids taller
Cuneiform:
- Support the wall of the laryngeal vestibule
What is the larynx suspended from?
Hyoid Bone
Where do both the pharynx and larynx end?
C6 (cricoid is here)
**Also the point where the vertebral artery enters the transverse cervical foramen
What do the inferior horns of the thyroid cartilage articulate with?
- What kind of movement is allowed
- Cricoid
- Allows thyroid cartilage to rock anteriorly and posteriorly over the cricoid
What happens when the thyroid cartilage rocks over the cricoid cartilage?
- The vocal folds are stretched and relaxed
* This allows us to make high and low pitch noise
What 3 muscles attach to the oblique line of the thyroid cartilage?
- Sternothryoid
- Thyrohyoid
- Inferior Pharyngeal Constrictor
What direction does the epiglottis fold when you swallow?
Posteriorly
What 3 structures is the epiglottis attached to?
- Base of the Tongue
- Hyoid Bone
- Thryoid cartilage
What is formed at the attachment of the tongue to the epiglottis?
Median and Lateral Glossoepiglottic Folds
What Is formed between the glossoepiglottic folds?
Vallecula
**Small intentions where things can get caught
Where does the epiglottic cartilage meet the thyroid cartilage?
- Attaches to the interior surface of the thyroid cartilage in midline (where two Laminae meet)
What forms the medial and lateral borders of the piriform recess?
Medial:
Cricoid and Arytenoid Cartilage
Lateral:
Thyroid Cartilage
What separates the Supraglottic space from the piriform recess?
Aryepiglottic Folds
What is included in the glottis?
Includes the Vocal Folds and the space between them
What is the space between the VOCAL folds called?
Rima Glottidis
What is the extent of the infraglottic space?
- Vocal Folds to Inferior aspect of cricoid cartilage
T or F: the vestibular folds are often known as Faslse vocal cords
True
What are the posterior and anterior attachments of the vocal ligament?
Anterior:
Thyroid Cartilage
Posterior:
Vocal process of Arytenoid cartiages
Where are the attachments of the Vestibular ligament relative to the vocal ligament?
Thyroid Anteriorly and Arytenoids Posteriorly but more superior and lateral than the true vocal folds.
Movement around the verticle axis of the arytenoids brings about what motion in the vocal ligaments?
- Abduction
- Adduction
What are the boundaries of the quadrangular membrane?
- Anteriorly
- Posteriorly
- Inferior/Medially
- Superior/Laterally
Anteriorly:
Epiglottic Cartilage
Posteriorly:
Arytenoid Cartilage
Inferior/Medially:
Vestibular Ligament/Fold
Superior/Laterally: Aryepiglottic Fold (when covered)
What is formed between the vestibular and vocal folds?
The Ventricle
What ligament thickens to form the vocal ligament/fold?
- Conus Elasticus
What are the borders of the Conus Elasticus?
- Anteriorly
- Posteriorly
- Laterally
- Medially
Anterior:
Thyroid Cartilage
Posterior:
Vocal Process of Arytenoid Cartilage
Laterally:
Cricoid Cartilage
Medially:
Vocal Ligament
What is the job of the Intrisic Muscles of the Larynx?
- Protect against entry of Foreign materials
- Expel Objects
- Tune vocal folds
What part of the larynx creates speech?
- Larynx Creates a buzzing tone, everthing above creates speech
What does Flexion of the Cricothryoid muscles do the vocal folds?
- What joint is moving
- Pulls them down ANTERIORLY by pulling (rotating) down thyroid cartilage
- INCREASES tension by INCREASING fold length
- Cricothyroid Joints
What is the only 1 of the 7 intrinsic laryngeal muscles that is not innervated by the inferior layngeal n.?
- What is its innervation?
- Cricothyroid
- Superior Layngeal n. (EXTERNAL branch)
T or F: the nerve to the cricothyroid passes through a hole in the thyroid membrane.
FALSE, Cricothryoid is innervated by the EXTERNAL branch of the Superior Laryngeal n. but the INTERNAL branch passes through the Thyroid membrane (with superior Laryngeal a. => superior thyroid a.)
Fibers from what muslce ascend to the aryepiglottic fold and blend with the aryepiglottic muscles along the laryngeal inlet?
Thyroarytenoid muscle
Fibers of the Thyroarytenoid muscle that attach to the eppigottis are given a different name.
- Name?
- What do they do?
- Thyroeppiglottic muscles
- Work WITH the Thyroarytenoid Muscles to pull down the epiglottis to cover the laryngeal inlet
What muscle flexes to shorten the vocal folds and oppose the action of the cricothyroid m.?
- Thyoarytenoid
What makes up the intercartilagenous and intramembranous glottis?
Intermembranous:
-True vocal folds and space between them
Intercartilagenous:
- Vocal Processes of Arytenoid Cartilages and the Space between them
What is the space between the vocal cords called?
Rima Glottis
What muscles are flexed and relaxed during normal breathing?
Flexed:
- Posterior Arytenoids
Relaxed:
- Transverse and Oblique Arytenoids
***Since we spend most of our time breathing the POSTERIOR Arytenoids are FLEXED most of the time
**What muscles are contracted during normal Speaking?
- Lateral Arytenoid
2. Transverse and Oblique Arytenoid
**What is the status up the intermembranous and intercartilaginous parts of the larynx during speaking?
- CLOSED
**What regulates tension on the vocal Cords during normal speaking?
- Thyroartenoid (loosens, deepens)
- Vocalis (controls tone?)
- Cricoarytenoid m.
What shaped the tone produced by the vocal cords into speech?
- Pharynx
- Oral Cavity
- Nasal Cavity
- Tongue
- Lips
What 5 characteristics control the vibration of the vocal folds?
- Level of ADduction
- Thickness of Vocal Folds
- Length of Vocal Folds
- Tension on Vocal Folds
- Breath
What controls the level of ADDUCTION of the vocal cords?
- what if these muscles are weak?
- How Strongly the Cricoarytenoids are contracting
- Weak muscles = Breathy sound
What controls the THICKNESS of vocal folds?
- Thin vocal cord sound
- Thick vocal cord sound
- Cricothyroid mm.
- Vocalis m.
THIN:
High Pitched Voice
THICK:
Deep voice
What aspect of the sound of speech is controlled by TENSION on the vocal folds?
- Affects tone PITCH
- Too much causes tightness in the throat and harsh tone
Describe how the following change moving from low to high tone?
- Length INCREASES
- Tension on Vocal folds INCREASES
- Thickness of Vocal folds DECREASE
How can the intermembranous Glottis close Independently of the Intercartilaginous glottis?
Contract:
LATERAL cricoarytenoids
Relax:
Transverse and Oblique arytenoids
T or F: the vocal cords vibrate during a whisper.
FALSE, the air passing through is shaped into recognizable sounds by the structures of Superior Larynx
What is the state intermembranous glottis and intercartilaginous glottis during coughing?
- muscles controlling this?
- both are SHUT tight
Flexed:
- Lateral Arytenoids
- Transvers and Oblique Arytenoids
What are the fiber types and action of the INTERNAL branch of the SUPERIOR LARYNGEAL n.?
GSA:
Mucosa and Glands Down Above Vocal Folds (Including Ventricles and sacculus)
GVA:
Mucosa and Glands Down Above Vocal Folds (Including Ventricles and sacculus)
SA:
Taste (base of tongue epiglottis)
What nerve descends under the tendinous arch between the thyroid and cricoid cartilages?
- What does it innervate
- EXTERNAL SUPERIOR Laryngeal n.
- Innervates Cricothyroid
***this happens after it pierces and innervates the inferior constrictor (which creates the arch)
What are the fiber types and action of the INFERIOR laryngeal n.?
- BE to ALL Intrinsic Muscles of larynx (EXCEPT Cricothyroid)
- GVE: all glands and mucosa BELOW vocal folds (including conus elasticus ligment)
- GSA: Below Vocal folds (including conus elasticus ligment)
What are the fiber types and actions of the EXTERNAL branch of the superior laryngeal n.?
- BE - Cricothryoid Muscle
What nerve gives parasympathetic innervation to the epiglottis, tongue, laryngeal inlet, and vestibule?
- GVE fibers of Internal Superior Laryngeal n.
What is the terminal branch of the recurrent laryngeal nn.?
- Inferior Laryngeal n.
Give the path of blood from the subclavian a. to the laynx.
- Subclavian a.
- Thyrocervical trunk
- Inferior Thyroid a.
- Interior Laryngeal a.
Give the path of blood from the external carotid a. to the larynx.
- External Carotid a.
- Superior thyroid a.
- Superior laryngeal a. (actually pierces thyroid membrane w/ the v. and n.)
What are some risk factors for laryngeal cancer?
- Smoking
- Drinking
- Weak Immune System
- GERD
- Male
What causes a hemmoragic polyp on the vocal cords?
- Broken Capillaries
**Polyp can hit the other side and cause some calluses to form
What is the key indicator that something could be wrong with the larynx or its innervation?
Hoarseness
What nerves are at risk in surgery on the carotid and what effect would this have?
**Note this is a unilateral lesion so loss of function would only occur on the side of the injury
- Cervical Portion of Vagus
- Cut this and you would probably die - Superior Laryngeal n.
Internal portion:
- Loss of sensation in the and parasympathetic activity of mucosa and glands down to vocal folds (GSA, GVE)
- Loss of some taste (SA)
External Portion:
- Loss of function of Cricothyroid (no anterior down rotation of thyroid cart.)
What nerves are at risk in surgery on the thyroid and what is the effect of hitting these?
**Note this is a unilateral lesion so loss of function would only occur on the side of the injury
- Inferior Laryngeal
- Hit only one side you probably would have hoarseness of voice due to loss of function of the intrinsic muscles of the larynx (BE)
- No parasympathetic activity below vocal folds (GVE)
- No sensory below folds (GSA)
- External Branch of Superior laryngeal n.
- loss of function of Cricothyroid
What would a pancoast tumor affect?
- RIGHT RECURRENT LAYNGEAL => inferior laryngeal a. on the right
- Hoarseness of the voice
Would a pancoast tumor on the left lung apex have the same effect as the right?
- NO because on the left side the LEFT recurrent laryngeal is around the arch of the aorta and travels more medially
When would lung cancer affect the LEFT recurrent laryngeal?
- If they metastasize to the Mediastinum or to the Tracheobrochial lymph nodes
What should you think when you hear about a problem with the LEFT vocal cord?
- Cancer in the CHEST near Left Recurrent Laryngeal
What shoud you think when you hear about a problem with the RIGHT vocal cord?
- Pancoast tumor (ON RIGHT lung apex)
