Laryngeal and Vocal Fold Physiology Flashcards
Name some primary biological functions of the VFs
regulate airflow in and out of respiratory tract
protective-close when we swallow
species-specific vocalizations
Why do VF tissues change dynamically?
to adjust pitch and loudness of vocalizations
What kind of structure are the VFs?
LAYERED
VF epithelium
anchored to the remainder of fold
Which layer of the Lamina Propria vibrates a lot?
superficial
What kind of fibers is the superficial layer of the Lamina Propria made of mostly?
elastic fibers
What kind of fibers is the deep layer of the Lamina Propria made of?
collagenous fibers
What kind of fibers is the intermediate layer of the Lamina Propria made of?
elastic, BUT is less flexible and more dense than the superficial layer
VF is also made up of which muscle?
the TA
Cover of VF
epithelium and superficial layer of lamina propria
Transitional Zone of VF
intermediate and deep lamina propria
Body of VF
the muscle-TA
Differences between cover, transitional zones, and body
cover and transitional zones are passively regulated while the body can be actively regulated
Medial Compression
forces that act to approximate the VFs at midline
-combo of LCA and IA to rotate the arytenoid cartilages
Longitudinal Tension
- stretching forces applied to VF tissue
- use of CT, TA, and extrinsic mm’s
What is the relationship between compression forces and the phonatory threshold?
higher compression forces translate into a higher phonatory threshold for vibration initiation
-more compression, higher phonatory threshold
Pitch changes MAY result from..
changes in length and tension of VFs
What happens when the VFs increase in length?
increase in length of the overall VF by itself decreases thickness of VF which can function to elevate pitch if operating alone
Increase in TENSION is more important for pitch elevation. Tension increases dramatically because..
changes in eleastic nature of VF tissue when it is lengthened due to antagonistic contraction of TA and CT
What is pitch?
relates to the frequency of VF vibration
Frequency
is an objective measure of a physical phenomenon
-rate at which an object vibrates and is measure in Hz
Describe the contraction of CT alone
stretches vocal ligaments and VF tissue
does not significantly increase pitch
Describe TA contraction alone
only acts to shorten the VFs and decrease the distance between the thyroid and arytenoid
What happens when these actions occur simultaneously?
effective longitudinal tension builds
Why does PCA activity increase slightly during pitch shifts?
may function to prevent a forward movement of the arytenoid cartilage when the CT contract and pulls TA thinner
may act to anchor the arytenoid from the strain of tension also
What happens when these actions occur simultaneously?
effective longitudinal tension builds
Why does PCA activity increase slightly during pitch shifts?
may function to prevent a forward movement of the arytenoid cartilage when the CT contract and pulls TA thinner
may act to anchor the arytenoid from the strain of tension also
Name some primary biological functions of the VFs
regulate airflow in and out of respiratory tract
protective-close when we swallow
species-specific vocalizations
Pitch lowering is primarily achieved by what?
changes in TA activity
How does the TA lower pitch?
- reduction in distance between thyroid and arytenoids
- vocal ligament becomes relaxed as a consequence
In general, intensity is regulated by..
the degree of medial compression in the glottis and greater respiratory drive
What does more medial compression result in?
greater levels of resistance to air flow, thus producing an increase in Psg
