Exam 2: Phonation II Flashcards
Interarytenoid Muscles
- Adductors
- located on the posterior surfaces of the arytenoid cartilages
- Described as oblique and transverse arytenoid muscles
Oblique arytenoid muscle characteristics
- more superficial
- looks like an X
- a few muscle fibers continue around the apex of the arytenoid cartilage laterally, angle upward and forward, and insert into the lateral borders of the epiglottis as the aryepiglottic muscle
Oblique Arytenoid: Origin & Insertion, function
Origin: posterior surface of the muscular process and adjacent posterlateral surface of one aryenoid cartilage
Insertion: near the apex of the opposite cartilage
Function: approximate the arytenoid cartilages and are therefore regulators of medial compression
Transverse Arytenoid Muscle: Origin & Insertion, function
Origin: from the lateral margin and posterior surface of one arytenoid cartilage, course in a horizontal direction
Insertion: lateral margin and posterior surface of the opposite arytenoid cartilage
Function: contraction approximates the arytenoid cartilage by causing them to slide along the long axis toward the midline
Cricothyroid Muscle characteristics
- tensor
- actively tense or elongate the VF
- only other tensor (than thyroarytenoid muscle)
- fan-shaped
oblique fibers– pars oblique
anterior fibers– pars recta
Cricothyroid Muscle: Origin & Insertion
Origin: anterolateral arch of the cricoid cartilage
diverges and
Insertion: the thyroid cartilage as two distinct parts
Pars Oblique
lower fibers course upward and back to inset into the anterior margin of the inferior horn of the thyroid cartilage
Pars Recta
upper or anterior fibers course nearly vertical upward to insert along the inner aspect of the lower margin of the thyroid
2 parts of the arytenoid muscle
oblique and transverse
5 distinct layers of the VF
- Epithelium (cover)
- superficial layer of the lamina propria (cover)
- Intermediate layer of the lamina propria (transition)
- Deep layer of the lamina propria (transition)
- vocalis muscle (body)
Epithelium of VF
made of: squamous epithelium
- thin and stiff capsule
- maintains shape of the vocal fold (like a capsule would)
- helps regulate VF hydration
Superficial layer of the lamina propria
- Reinke’s space
- consists of loose fibrous components and elastic components in a matrix
- mass of soft gelatin
Intermediate layer of the lamina propria
made of: elastic fibers
- likened to a bundle of soft rubber-bands
- composed mostly of elastic fibers
Deep layer of VF
made of: collagenous fibers
- like a bundle of cotton threads
- made up of collagenous fibers, contributes to durability of VF
Vocalis Muscle in VF
- has both passive and active mechanical properties
- constitutes the main body of the VF
- passively, is like a bundle of stiff rubberbands
- it is a muscle, so it is active (contractile properties, help control stiffness)
Thyroarytenoid Muslce (TA)
- main mass of the VF
- vocalis muscle (medial bundle) flanks the vocal ligament
- thyromuscularis (lateral bundle) serves as the “body” of the muscle
Vocal Fold’s 3 sections
- the cover (epithelium and superficial layer of lamina propria), aslo called mucosa
- transition (intermediate and deep layers of lamina propria; this is the vocal ligament
- Body (vocalis muscle)
Physiology of VF (Thyroarytenoid)
- the mechanical properties of the outer four layers are controlled passively
- mechanical properties of the body are regulated both passively and actively
- during phonation, a wave traveling on the laryngeal mucosa from its inferior to superior surface can be seen during each cycle of vocal fold vibration, except when the vocal fold is very tense (ex: falsetto)