Last lecture 1 Flashcards
What does the larynx open into?
the laryngopharynx below the oropharynx
The laryngopharynx is primary a ____
sphincter
What is the primary feature/action of the laryngopharynx?
separates the respiratory from the digestive tracts
What is a secondary feature of the the laryngopharynx?
phonation
What is the larynx composed of?
skeleton of cartilages held together by fibrous membranes
What maintains the shape of the cartilages of the larynx?
intrinsic muscles of the larynx
What cartilage is the foundation of the laryngeal skeleton?
cricoid cartilage
The cricoid cartilage can be described as what type of ring?
A signet ring because it is thinner anteriorly
What cartilages articulate with the posterior aspect of the cricoid cartilage?
two arytenoid cartilages
What shape are the arytenoid cartilages?
pyramidal
The arytenoid cartilages have what coming off of them?
two processes: the vocal process the muscular process
Where does the vocal process attach to from the larynx?
the vocal ligament
What kind of articulation do the arytenoid cartilages have with the cricoid?
a synovial articulation, with the cricoid enabling them to rotate around a vertical axis
What shape is the thyroid cartilage?
sheild-shaped
What are the horns sticking off the thyroid cartilage called?
inferior cornu
What does the inferior cornu articulate with?
also with the cricoid cartilage
What form’s the laryngeal prominence (adam’s apple)?
the two lamina of. the thyroid meeting in the midline
What is the epiglottis?
a leaf-like cartilage attached to the internal aspect of the upper border of the thyroid
Where does the free upper border of the epiglottis project to?
above the level of the thyroid
What is the action of the epiglottis?
during swallowing, it folds posteriorly over the opening of the larynx directing food and water into the esophagus
What kind of cartilage is the epiglottis composed of? What about the other cartilages?
elastic cartilage; hyaline cartilage
Laryngeal cartilages are linked by fibrous membranes to what?
each other, the hyoid bone above, and the first tracheal cartilage below
A thickened within the fibrous membrane linking the laryngeal cartilages may be considered a what?
a ligament
What does the thyrohyoid membrane link together?
the hyoid bone to the thyroid cartilage
The thyrohyoid membrane is thickened in the middle to form what and laterally to form what?
the median thyrohyoid ligament and the lateral thyrohyoid ligament
What does the cricotracheal ligament join together?
cricoid cartilage to the first tracheal cartilage
what does the cricothyroid membrane join?
the cricoid cartilage, the thyroid and arytenoid cartilages
The upper free border of the cricothyroid membrane extends where?
from the vocal process of the arytenoid cartilage to the deep surface of the thryoid cartilage, meeting its counterpart from the opposite side at midline
Where the upper free border of the cricothyroid membrane meets at midline is called what?
vocal ligament
What is the median cricothyroid ligament?
a midline thickening in the cricothyroid membrane
What is the quadrangular membrane?
a thinner membrane that joins the arytenoid cartilage to the epiglottis
The lower free border of the quadrangular membrane forms what?
the vestibular ligament
What kind of musculature does the larynx have?
both intrinsic and extrinsic
What is the action of the extrinsic larynx muscles?
stabilize or move the larynx as a whole
What muscles are depressors of the larynx and hyoid?
infrahyoid muscles
What muscles are elevators of the larynx and hyoid?
suprahyoid muscles
What is the action of the intrinsic muscles of the larynx?
alter the position of one part of the laryngeal skeleton relative to the others
the action of the intrinsic larynx muscles results in what?
alteration of the length and tension of the vocal cords or the size and shape of the rima glottidis
Where does the posterior cricoarytenoid mm. extend?
arise from the posterior aspect of the cricoid cartilage and extend superolaterally to insert into the muscular process of the arytenoid cartilage
Action of the posterior cricothyroarytenoid mm.
pull back on the muscular process rotating the arytenoid process and thereby swinging the local processes laterally separating the vocal folds
The separation of the vocal folds by the posterior cricoarytenoid mm is called what?
aBduction of vocal folds
What is the only aBductor of the larynx?
posterior cricoarytenoid mm.
What two muscles pass between the two arytenoid cartilages and draw the cartilages together, therefore aDducting the vocal folds?
transverse and oblique arytenoid mm.
What muscle inserts on the muscular process of the arytenoiud cartilages and aDducts the vocal folds?
lateral cricoarytenoid mm.
What muscles lie within the larynx and lateral to the vocal fold?
thyroarytenoid mm.
A bundle of the lower fibers from the thyroarytenoid mm. attaches to t he vocal process of arytenoid cartilage and is renamed what?
vocalis muscle
The cricothyroid m. does what action?
stetches and tenses the vocal ligament
What is the only intrinsic larynx muscle to not be innervated by the recurrent laryngeal n and what is it innervated by instead?
cricothyroid muscle; it is innervated by external laryngeal n.
Damage to the recurrent laryngeal nerves during thyroidectomy leads to what?
damage to the vocal cords on the affected sides causing a hoarse voice
Damage to both of the recurrent laryngeal nerves causes what?
reduces the voice to a whisper and may produce respiratory distress
the mucus membrane above the vocal folds receives sensory innervation from where and blood supply from where?
internal laryngeal nerve and superior laryngeal artery
Where does superior laryngeal artery come from?
super thyroid a.
the internal laryngeal n. and superior laryngeal a. pierce through what together?
thyrohyoid membrane
the mucous membrane below the vocal folds is innervated by what and supplied by what artery?
recurrent laryngeal n. and inferior laryngeal artery
Where does inferior laryngeal artery come from?
inferior thyroid artery
the orbit is a four-sided ___ with the apex facing?
triangle, inward
what are the four sides of the pyramidal shape of the orbit lined by?
thickened funnel shape fascial layer called the preorbita.
what walls of the orbital fascia are the thinnest? what are they a clinical threat of becoming eroded by?
medial and floor of the orbit are the thinnest, clinical threat of becoming eroded by persistent infection of ethmoidal or maxillary sinuses.
where is the lacrimal gland located? how many openings does it have? what is secreted where?
located in the superolateral aspect of the orbit, 9-13 openings that secrete tears into the conjunctival sac.
how do the conjunctiva and cornea stay moist and lubricated?
blinking sweeps the tears across the eye and conjunctiva sac medially.
how is the tears drained from the eye medially?
by the punctum, on the medial aspect of each eyelib.
where does fluid go after draining into the punctum ?
into the nasolacrimal duct that opens under the inferior chonca on the lateral wall of the inferior meatus.
each eyelid contains and semilunar shaped plate of dense connective tissue called the ?
tarsal plate
what are embedded into the tarsal plates? what do they secrete?
tarsal glands that secrete a fatty substance that functions in preventing the eyelids from sticking together when closed.
how are the tarsal plates anchored to the bony orbit?
medial and lateral palpebral ligaments
what is the voluntary skeletal muscle that raises the upper eyelid?
the levator palprebrae superioris
what muscle assists the levator palpebrae superioris ?
the superior tarsal muscle is a smooth fatigue-resistant muscle that assists in holding the eyelid in the open position. responsible for the tone of the eyelid.
how does the eyelid rest in the raised position?
just above the iris of the eye.
what innervates the superior tarsal muscle? what happens if this was lesioned?.
sympathetic fibers that travel with the frontal nerve, a lesion of the superior cervical ganglion (horners syndrome) can cause the tone to be lost and the eyelid to fall below the pupil.
name the extraoccular muslces?
superior, medial, lateral, inferior rectus
superior/ inferior oblique
levator palpebrae superioris.
