the Larynx Flashcards
what are the 3 single cartilages?
epiglottis, cricoid, thyroid
what are the 3 paired cartilages?
arytenoids, corniculates, cuniforms
hyoid bone
- not part of larynx but many laryngeal structures connect to it
- suspened and attached via ligaments + muscles
- U-shaped with corbus (body) anteriorly, and open posteriorly, cornea are 2 ‘horns’ at either side
Thyroid carticlage
- sg + largest
- 2x lamina plates fused together in V-shape forming larygeal promience anteriorly
- x2 superior cornea which are connected to hyoid via thyrohyoid muscles
- x2 inferior cornea which connect to cricoid forming the crico-thyroid pivot joint
- made of hyaline cartilage
Epiglottis
- sg
- leaf-shaped
- made of elastin cartilage
- connects to thyroid via the thyroidepiglottic ligament and the base of the tongue
- protects airway and structures of larynx during swallowing by folding posteriorly
Cricoid Cartilage
-sg + ‘ring’ shaped
-sits just superior to tracheal rings at base of larynx
-relatively stationary
-taller posteriorly than anteriorly
attached posteriorly and laterally to arytenoids via the cricoaryntenoid muscles
-attached anteriorly to thyroid via cricothyroid muscle
Arytenoid cartilages
- paired
- pyramid shaped
- attached to vocal folds via ligaments
- attached superiorly to corniculates via a ball-socket joint
- adduction and abduction causes movement of vocal folds
Coniculate Cartilages
- paired
- attached inferiorly to aryntenoids via a ball-socket joint which enables rotation and gliding forwards and back
- have no role in speech production
Cuniform Cartilages
- paires
- ‘hidden’ w/in larynx
- no role in speech production
Intrinstic muscles
- connect laryngeal structures TO EACH OTHER (w/in larynx)
- cause movement of individual laryngeal structures but not whole larynx
- responsible for vocal fold movement
- regulate size & shape of glottal space
- 5 paired muscles
what are the instrintic muscles
5-paired:
- Thyroaryntenoids
- Posterior Cricothyroids
- Lateral Cricothyroids
- (Anterior) Cricothyroids
- Arytenoids
Thyroidaryntenoid muscles
- sometimes called ‘vocalis muscles’
- instristic (paired)
- connect thryoid to aryntenoids
- cause adduction and abduction of vocal folds
- regulate glottal space
cricothyroid muscles
-x3 paired: posterior, lateral, anterior
-connect cricoid and thyroid
instrisic (paired)
arytenoid muscles
connect both aryntenoids
intristic (paired)
Extrinstic laryngeal muscles
- connect laryngeal structure to structures OUTSIDE the larynx (often hyoid)
- cause movement (depression + elevlation) of WHOLE larynx (e.g. during swallow)
- 2 subcategories: supra + infra hyoid
Extrinstic suprahyoid muscles
connect laryngeal structures to structures above the hyoid bone 6 muscles: -digastrius -stylohyoid -mylohyoid -hyoglossis -genoglossis -geniohyoid
Extrinstic infrahyoid muscles
connect laryngeal structures to structures below the hyoid
3 muscles:
-thyrohyoid (attaches thyroid to hyoid)
-Sternohyoid (runs between sterm and hyoid)
-Omohyoid (paired)
Cranial Nerves affecting the larynx
- Trigenmedial (V)
- Facial (VIII)
- Vagas (X)
- Hypoglossal (XII)
which crancal nerve controls all intrinsic muscles
Vagas (X)
Types of connective tissue found in the larynx
tendons, ligaments, mucus membrane
what do tendons connect
muscle to cartilage
what do ligaments connect
muscle to muscle
what are mucus membranes
tissues which surround structures to protect them
what are the 2 paired liagments on the larynx
- Vesticular (false VF)
2. True VFs
Vocal Cords
thyroidaryntenoid muscles which abduct and adduct
Vocal folds
mucus membranes covering vocal cords to protect them (2x paired)
True VFs
- involved in phonation
- directly surround vocal ligaments and thyroiaryntenoid muscles
- pealy white in colour
Vestricular folds
- False VFs
- lie parellel and slight superior to true VFs
- no role in phonation
adducted VFs
when VFs are together, adducting is the movement of VFs together (abducted->adducted)
Abducted VFs
when VFs are apart, abducting is the movement of VFs away from each other (adducted->abducted)
how does pitch alteration occur
altering tension, stretch and contraction of VFs which changes rate of vibration (quicker vibration=increased strectch = increased pitch)
what does altering the relationship b/w the cricoid and thyoid cartilage do?
alter length of VFs
