Tag Archives: Anatomy & Physiology
Supraglottic phonation
Making voice by means of supraglottic vibration rather than glottic (true vocal cord) vibration. The supraglottic tissues used for vibration can vary between individuals. Vibrating tissue can be the false vocal cords (false cord phonation), aryepiglottic cords, or apical arytenoid mucosa.
Supraglottic phonation may become necessary if the vocal cords are absent or scarred to the point of being unable to vibrate. Examples might include larynx trauma, partial laryngectomy with loss of one or both vocal cords or an inability to bring them close enough together to be entrained into vibration, or progressive radiation damage (radiation fibrosis), usually many years after treatment for cancer.
Photos:
False cord phonation due to flaccid true cords (1 of 5): before false cords begin to vibrate
An elderly man, quiet by nature who uses the voice little, complains of weak, gravelly voice quality. This view of phonation, standard light, shows a slightly wider dark line of phonatory blurring. Also, the false vocal cords are overly approximated, but not yet participating in vibration (for that, see images 4 and 5).
False cord phonation due to flaccid true cords (2 of 5): before false cords begin to vibrate
Strobe light reveals an unusually wide amplitude of vibration, denoting flaccidity of the true vocal cords.
False cord phonation due to flaccid true cords (3 of 5): before false cords begin to vibrate
Maximum closed phase shows the telltale residual opening at the anterior commissure (from this perspective, the lowermost end of the true cords), also a potent indicator of flaccidity.
False cord phonation due to flaccid true cords (4 of 5): after false cords begin to vibrate
When asked to produce louder voice, the false cords begin to participate in vibration, and a rough, gravelly superimposed “godfather” quality arrives. Notice that the true cords are in at least partial open phase of vibration.
False cord phonation due to flaccid true cords (5 of 5): after false cords begin to vibrate
Now the false cords are in open phase of vibration, and the true cords are in maximum closed phase of vibration, with the same residual opening anteriorly seen in photo 3. False cord phonation is not to be seen most accurately as primary here, but as a secondary result of effort necessitated by flaccid true cords.
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Supraglottic phonation (1 of 6)
After right hemilaryngectomy for cancer, performed
elsewhere, breathing position. Notice the left vocal cord (right of image) is partially intact (arrow), though with scarring at its anterior end (at “S”).
Supraglottic phonation (2 of 6)
During supraglottic phonation using conventional view, true vocal cords cannot be seen.
Supraglottic phonation (3 of 6)
Under strobe illumination. With assistance of topical anesthesia, during high pitched phonation, is the only “true vocal cord voice” this patient can achieve. This is the “closed” phase of vibration, though of course the glottis is not truly closed as one can see from the persistence of the black glottal gap.
Supraglottic phonation (4 of 6)
Same view as photo 3, still under strobe illumination, now with left vocal cord slightly lateralized for the “open phase” of vibration. Note that the black glottal gap is slightly wider. This “glottic” or true vocal cord voice is extremely breathy and high-pitched, and will not serve the patient’s vocal needs.
Supraglottic phonation (5 of 6)
Strobe view during supraglottic phonation, using a much lower pitch and with a rough vocal quality. This is the “closed” phase of vibration with residual aryepiglottic and false cord tissue at "X" partially closing at the level of the intact left false vocal cord.
False cord phonation
Making voice by vibrating the false vocal cords. This kind of phonation is unlike normal phonation or voice-making, which uses the true vocal cords.
False cord phonation produces a much deeper, rougher voice quality than normal phonation. It is purposefully used in certain kinds of vocal performance, such as Tibetan chant or heavy metal screaming. It can also occasionally serve as an alternate voice for a person whose true cords are unable to vibrate—due, for example, to their surgical removal or to scarring. It can also be produced concurrently with true cord phonation to produce a “Louis Armstrong” effect.
Photos:
False cord phonation due to flaccid true cords (1 of 5): before false cords begin to vibrate
An elderly man, quiet by nature who uses the voice little, complains of weak, gravelly voice quality. This view of phonation, standard light, shows a slightly wider dark line of phonatory blurring. Also, the false vocal cords are overly approximated, but not yet participating in vibration (for that, see images 4 and 5).
False cord phonation due to flaccid true cords (2 of 5): before false cords begin to vibrate
Strobe light reveals an unusually wide amplitude of vibration, denoting flaccidity of the true vocal cords.
False cord phonation due to flaccid true cords (3 of 5): before false cords begin to vibrate
Maximum closed phase shows the telltale residual opening at the anterior commissure (from this perspective, the lowermost end of the true cords), also a potent indicator of flaccidity.
False cord phonation due to flaccid true cords (4 of 5): after false cords begin to vibrate
When asked to produce louder voice, the false cords begin to participate in vibration, and a rough, gravelly superimposed “godfather” quality arrives. Notice that the true cords are in at least partial open phase of vibration.
False cord phonation due to flaccid true cords (5 of 5): after false cords begin to vibrate
Now the false cords are in open phase of vibration, and the true cords are in maximum closed phase of vibration, with the same residual opening anteriorly seen in photo 3. False cord phonation is not to be seen most accurately as primary here, but as a secondary result of effort necessitated by flaccid true cords.
Thin and weak voice (1 of 4)
This man has a thin and weak voice, often with a superimposed gravelly, rough quality. In this view, false cords, marked with dotted lines, obscure the true cords and their vibration is indicated by blurred margins.
True cords during closed phase (2 of 4)
At much closer range under strobe light, the true cords are approximated during the closed phase of vibration. The false cords should remain lateralized throughout voice production (but don’t).
Flase cords during open phase (3 of 4)
From same viewing position, but during open phase of vibration, showing very “wide” amplitude of vibration caused by flaccidity. The false cords are beginning to come together.
Bowing (1 of 4)
The true cords are together posteriorly but with major bowing seen at the pre-phonatory instant, to explain the husky, weak quality of voice.
Closed phase (2 of 4)
As a result of the need to compress together the weak true cords, false cords also overcompress. This is closed phase of true cords; false cords have not yet reached midline as they are vibrating more slowly than the true cords.
False cord phonation (3 of 4)
Now the false cords have come into contact but below them the true cords have begun their open phase of vibration. We hear the husky, weak true voice with the superimposed rough, gravelly false cord phonation.
True cords vibrate (1 of 4)
At relatively high pitch, only the true cords vibrate. This is closed phase, under strobe light.
True and false cords, closed phase (3 of 4)
At low pitch, where false cord phonation is facilitated. Both true and false cords are in closed phase of vibration (though the true cords are obscured by the false cords).
Hemilaryngectomy (1 of 4)
After removal of the anterior larynx (hemilaryngectomy) for cancer that recurred after radiation therapy. Though not well seen here, the vocal cords are surgically absent. The black dot seen is for orientation to the next photo. A = arytenoid; E = epiglottis.
Within the larynx (2 of 4)
A view within the larynx. Note again that vocal cords are surgically absent, with only the arytenoid cartilages remaining at the level of the cords. The black dot, on the left arytenoid cartilage, orients to the prior photo. The dot is on the right vocal process.
"Wolfman Jack" voice (3 of 4)
The patient is about to produce his rough, “Wolfman Jack” voice but the arytenoid mounds have not yet started to vibrate.
Audio:
True cord phonation
False cord phonation
True and false cord phonation
Laryngeal vestibule
The “airspace” above the level of the vocal folds that is bounded by the posterior surface of the epiglottis, the medial surfaces of the aryepiglottic folds, and the anterior faces of the arytenoid cartilages.
Tracheoesophageal party wall
The membranous shared wall between the trachea and esophagus. The tracheoesophageal party wall is also known as the membranous trachea. This membranous wall makes up one-third of the trachea’s circumference; the other two-thirds is bolstered and stiffened by cartilaginous rings. These stiff cartilaginous rings help to keep the trachea open, whereas the membranous wall has some flexibility and may momentarily bulge into and narrow the tracheal passageway, as during a cough or a Valsalva maneuver.
Photos:
Tracheobronchial cough vibration (1 of 2)
Patient with SNC who is treated for presumed infection because of her congested rumbling “productive-sounding” cough. The "X" marks the same place in this photo and the following photo.
Tracheobronchial cough vibration (2 of 2)
Patient is at the moment of a deep, productive-sounding cough, but in fact it is not productive. Her many courses of antibiotics are probably unnecessary. The narrowing of the lumen is due to inward bulging of the membranous tracheal wall. The blur is caused by vibration during this cough.
Abducted breathing position (1 of 5)
Normal laryngeal entrance, with vocal cords in abducted (breathing) position.
View of mid-trachea (2 of 5)
View in normal mid-trachea. Note that the cartilaginous rings make up approximately 2/3 of the circumference and that the membranous trachea (upper photo at 'X') is more flat.
View just above the carina (3 of 5)
View just above the carina, where the distal trachea splits into left and right mainstem bronchi. Anterior take-off of carina at the 'X'. The straight line delimits the membranous (flexible) tracheal wall.
Wheezing begins (4 of 5)
With Valsalva maneuver to accentuate patient’s functional expiratory wheezing. Note that the membranous tracheal and bronchial walls bulge inward on a functional basis to narrow the airway. Wheezing begins to be heard. The 'X' again marks the anterior take-off of the carina. Compare with Photo 3.
Posterior commissure
The flat, front-facing surface of the glottic aperture that lies between the vocal cord’ posterior ends. When the vocal cords are in abducted (breathing) position, the posterior commissure is at its widest, since the cord’ posterior ends are spread furthest apart from each other. When the vocal cords have come together into adducted (voicing) position, the posterior commissure is essentially just the point of contact between the posterior ends of the cords.
In individuals who have acid reflux or other inflammatory conditions, the mucosa at the posterior commissure may thicken (pachyderma).
See also: anterior commissure.
Anterior commissure
The point at which the vocal cords are joined together, which is at the most anterior end of each cord. Compare this with the posterior commissure.
Hypopharynx
The inferior-most part of the pharynx, made up of the pyriform sinuses, the lowest part of the posterior pharyngeal wall, and the post-arytenoid/post-cricoid areas.
Pyriform sinus
Pyriform sinus refers to the pear-shaped fossa (Latin for “trench”) just lateral to the laryngeal entrance. Its medial surface is the aryepiglottic cord; laterally it is bounded by the thyroid cartilage, and posteriorly by the low posterior pharyngeal wall. The pyriform fossas and post-arytenoid area together constitute the “swallowing crescent,” which channels swallowed material just before it enters the esophagus, behind the larynx.
Vocal process
A projection of the anterior arytenoid cartilage, to which is attached the membranous vocal cord.
Photos:
Vocal processes, accentuated by vocal cord atrophy (1 of 3)
Panoramic view of the vocal cords just before voicing. Notice the obvious outline of both vocal processes. (For orienting, the processes are bounded at one end by small arrows.) The processes shine through particularly clearly due to the marked atrophy of the vocal cords as a whole.
Vocal processes, accentuated by vocal cord atrophy (1 of 4)
The vocal processes in this patient are extremely visible because the rest of the vocal cord on each side is atrophic and bowed.
Vocal processes, accentuated by vocal cord atrophy (2 of 4)
The vocal cords approach each other for voicing. Note the evident asymmetry between the vocal processes. The left vocal process (right of image) projects further anteriorly than does the opposite process. It is also at a higher (more cephalad) level.
Vocal processes, accentuated by vocal cord atrophy (3 of 4)
Phonation, closed phase of vibration, under strobe lighting. Note the overlap (scissoring) of the left vocal process (right of image) on top of the other process.