SLHS 3302 Exam 2

At constant temperature, a sealed gas container's volume is reduced to one-third. What happens to the pressure?

A. It falls to one-third

B. It stays the same

C. it triples

D. it doubles

C. It triples

Boyle's Law holds pressure and volume in an inverse relationship at fixed temperature (P × V is constant), so pressure increases as volume decreases

During quiet inhalation, air enters the lungs because:

A. the lungs actively suck air in with their own muscle

B. thoracic volume increases, which lowers alveolar pressure below atmosphere

C. alveolar pressure rises above atmospheric

D. the diaphragm pushes the air down into the lungs

B. thoracic volume increases, which lowers alveolar pressure below atmosphere

• When the diaphragm contracts and moves inferiorly and the external intercostals expand the rib cage, the thoracic cavity enlarges

• Boyle's Law a larger volume means a lower pressure, so air flows down the gradient into the lungs.

What couples the lung to the chest wall, so that the lung expands when the thorax expands?

A. The high positive pressure inside the pleural space pushing the lung open.

B.  A rigid bony connection between rib and lung.

C.  Direct muscle attachments running from the ribs into the lung tissue.

D.  The adhesive force of the pleural fluid.

the adhesive force of the pleural fluid

What actually produces the pressure a gas exerts on the walls of its container?

A. The weight of the container itself

B. a single strong push from the gas as a whole

C. the force of countless gas molecules colliding with the surfaces

D. the chemical bonding of the gas molecules to the container wall

C. the force of countless gas molecules colliding with the surfaces

Air moves into and out of the lungs because:

air flows down a pressure gradient, from an area of higher pressure to an area of lower pressure

Rank atmospheric, intra-alveolar, and intrapleural pressure from highest to lowest at the moment air is flowing into the lungs, and state what this means for intrapleural pressure relative to the atmosphere.

during inspiration, atmospheric pressure is greater than intra-alveolar pressure, and intra-alveolar pressure is greater than intrapleural pressure.

Which statement about quiet breathing is correct?

A. Inspiration is active; quiet expiration relies on passive elastic recoil

B. both phases are entirely passive

C. expiration is the active phase and inspiration is passive

D. both inspiration and expiration always require muscle contraction

A. Inspiration is active; quiet expiration relies on passive elastic recoil

what two muscle groups does inspiration use

1. diaphragm

2. external intercostals

A U-tube manometer shows a 10-centimeter water displacement while a person blows steadily into the connecting tube. What pressure is being reported, and why can this stand in for alveolar pressure?

Blowing into the tube displaces the water by a distance that corresponds to the pressure exerted, so you can use it as a pressure measurement. 10 centimeters of water are being reported.

During quiet expiration, air leaves the lungs because pressure within the lungs becomes:

A. lower than atmospheric pressure

B. zero

C. greater than atmospheric pressure

D. exactly equal to atmospheric pressure

C. greater than atmospheric pressure

Which statement correctly describes the passive force of breathing?

A. it is inherent and always present, arising from the elastic recoil of the apparatus - no muscle required

B. it is present only during expiration

C. it exists only when a large muscular effort is made

D. it is produced by contraction of the chest wall muscles

A. it is inherent and always present, arising from the elastic recoil of the apparatus - no muscle required

When the breathing apparatus holds more air than it does at rest, the passive recoil force tends to be:

Expiratory — it recoils toward a smaller size, like releasing a stretched spring.

The passive recoil force of the breathing apparatus is greatest when the apparatus is:

Farthest from its resting size, in either the stretched or the compressed direction. (like a coil spring)

At the resting position of the linked breathing apparatus, the pulmonary apparatus's tendency to ____ is balanced by the chest wall's tendency to ____.

A. collapse inward; also collapse inward

B. generate active muscle force; do the same

C. collapse inward; spring outward

D. spring outward; collapse inward

C. collapse inward; spring outward

• the pulmonary apparatus to collapse is opposed by an equal and opposite force of the chest wall to expand, giving a mechanically neutral, balanced state

When the pulmonary apparatus is removed from the chest wall, what resting state does it take, and what does that tell you about the kind of force it can exert?

the pulmonary apparatus rests in a collapsed state containing very little air — represented as a collapsed spring

A respiratory muscle whose isolated action increases lung volume is classified as:

an inspiratory muscle

A respiratory muscle whose isolated action decreases lung volume is classified as:

an expiratory muscle

Which description best fits the diaphragm?

 A. flat sheet of muscle with no tendon.

 B.A paired strap muscle running down the front of the neck.

 C. An unpaired, dome-shaped muscle with a strong central tendon that separates the thorax from the abdomen.

D.  One of the bones forming the floor of the thorax.

 C. An unpaired, dome-shaped muscle with a strong central tendon that separates the thorax from the abdomen.

Name two of the diaphragm's named fiber groups by their point of origin, and briefly state what the "zone of apposition" is.

the costal part originates from the inner surfaces of the last six ribs and their cartilages, and the sternal part originates from the inner surface of the xiphoid process of the sternum

The zone of apposition is the region — about 6 to 9 cm — where the costal diaphragm fibers lie directly apposed to the inner surface of the rib cage

During a forceful cough or very loud speech, which muscles are recruited to help drive air out?

A. the diaphragm and the external intercostals

B. no muscles at all - expiration is always passive

C. the pulmonary apparatus’s own muscle layer

D. the abdominal muscles and the interosseous internal intercostals

D. the abdominal muscles and the interosseous internal intercostals (both decrease lung volume)

A patient's lungs have become stiffer and harder to stretch than a healthy lung (a restrictive pattern). Using the concepts of passive and active force, explain: (a) what "passive force" and "active force" mean; (b) how the resting position of the breathing apparatus is set; and (c) how the increased stiffness would change the passive recoil this patient must contend with during a breath.

Passive force is the inherent, always-present elastic recoil of the apparatus (spring-like, no muscle needed), while active force comes from the contraction of the chest-wall muscles; either force can act in the inspiratory or expiratory direction; The resting position is when the pulmonary apparatus's inward recoil is opposed by an equal and opposite outward recoil of the chest wall. A stiffer, harder-to-stretch apparatus behaves like a stiffer spring, so a given deformation from rest now produces a greater passive recoil.; Consequence for the patient: the inspiratory muscles must generate more active force to stretch the stiffer apparatus open, since active muscular force is what departs from the passive resting condition

Inspiratory reserve volume (IRV) is best defined as the air that can be inspired:

A. that remains in the lungs after a maximal forced exhale

B. below a normal expiratory tidal volume

C. above a normal inspiratory tidal volume. maximal effort

D. during normal, quiet breathing

C. above a normal inspiratory tidal volume. maximal effort

The four respiratory volumes are described as mutually exclusive. This means:

A. each volume includes the one before it

B. they do not overlap - each is a seperate pocket of air

C. only one can be measured at a time

D. they cancel each other out

B. they do not overlap - each is a seperate pocket of air

Which sum correctly builds functional residual capacity (FRC)?

A. ERV + RV

B.  TV + IRV + ERV + RV.

C.  TV + IRV.

D.  IRV + TV + ERV.

A. ERV + RV

Suppose a spirometry workup gives a patient a total lung capacity of 6000 mL and a vital capacity of 4500 mL. Work out the residual volume, and explain how the structure of the capacities lets you do it.

RV = TLC − VC = 6000 − 4500 = 1500

Why can residual volume not be measured directly by spirometry?

because the lungs can never be voluntarily emptied, so some air always remains and never flows through the meter

Residual volume is functionally important because it:

A. adds to the total air you can move in and out

B. provides the air for a normal quiet breath

C. keeps the alveoli from collapsing, making breathing easier

D. is the largest volume you can forcibly exhale

C. keeps the alveoli from collapsing, making breathing easier

Lung volume is often expressed in percent vital capacity (%VC). Give the resting end-expiratory level in an upright body position, and explain the advantage of using %VC.

At the end of a resting tidal expiration in an upright (sitting or standing) body position, the breathing apparatus sits at about 40 %VC. Expressing volume as percent vital capacity allows breathing events to be compared across people of different sizes.

Vital capacity is best defined as the total amount of air that can be:

A. forcibly expired after a maximal inspiration (IRV + TV + ERV)

B. inspired after a tidal expiration

C. the sum of all four volumes

D. left in the lungs after a normal tidal expiration

A. forcibly expired after a maximal inspiration (IRV + TV + ERV)

A spirometry tracing shows a markedly reduced vital capacity, with the movable volumes all scaled down, in a patient whose lungs are stiff and hard to expand. Reasoning from the definitions of the volumes, this pattern is most consistent with:

A. a loss of residual volume

B. a person simply breathing quietly at the moment of the test

C. a perfectly normal, athletic breather

D. a restrictive pattern, in which a stiff, hard to expand apparatus limits how much air can be moved

D. a restrictive pattern, in which a stiff, hard to expand apparatus limits how much air can be moved

Quiet, automatic ("tidal") breathing — the kind happening right now without your thinking about it — is generated primarily by neurons in the:

A. Spinal cord

B. cerebral cortex

C. Medulla of the brainstem

D. Limbic system

medulla of the brainstem

Breathing can be both involuntary and voluntary because:

A. Voluntary breathing bypasses the peripheral nerves

B. The lungs themselves decide when to switch modes

C. the brainstem generates the automatic rhythm, while higher brain centers govern special acts

D. two entirely separate sets of breathing muscles exist, one voluntary and one automatic

C. the brainstem generates the automatic rhythm, while higher brain centers govern special acts

"The nervous system controls breathing" becomes concrete when you can name the road the command travels. The diaphragm and chest-wall muscles receive their motor commands via:

A. cranial nerve (vagus) only

B. no nerve- the diaphragm contracts on its own

C. cranial nerve XII (hypoglossal)

D. spinal nerves

D. spinal nerves

• Twenty-two spinal nerves contribute to the control of breathing, supplying the diaphragm and chest-wall muscles, and control commands are sent to muscles through the peripheral nerves

Which nerve innervates the sternocleidomastoid, the muscle that elevates the sternum, clavicle, and rib cage?

A. The accessory nerve

B. vagus

C. glossopharyngeal

D. hypoglossal

A. The accessory nerve

• innervates the sternocleidomastoid muscle, which elevates the sternum, clavicle, and rib cage

While serving life through ventilation and gas exchange, the breathing apparatus also drives speech. Alveolar pressure most directly contributes to speech:

A. word meaning

B. nothing- during speech the apparatus stops serving ventilation

C. tongue placement for consonants

D. loudness (intensity)

D. loudness (intensity)

• a higher target alveolar pressure produces louder speech while a lower target produces softer speech

Explain how the breathing apparatus can power speech while still keeping you alive.

provides the driving forces that generate speech — contributing to loudness (intensity), voice frequency (pitch), — and at the same time it continues to serve its primary functions of ventilation and gas exchange The same air stream that powers speech is the air that keeps oxygen coming in and carbon dioxide going out

Compared with a sustained vowel (an extended steady utterance), running speech is characterized by:

A. no pressure changes at all across a spoken phrase

B. expiratory volume, duration, and alveolar pressure that vary breath to breath with phrase length, stress, and loudness

C. inspiration during which no air pressure is generated

D. a perfectly constant alveolar pressure held across the whole vital capacity

B. expiratory volume, duration, and alveolar pressure that vary breath to breath with phrase length, stress, and loudness

A frightened person begins to hyperventilate. This illustrates that:

A. emotion has no access to the breathing system

B. the medulla has stopped functioning

C. hyperventilation proves the lungs act independently of the brain

D. Emotional influences from higher brain areas can override the brainstem’s automatic breathing rhythm

D. Emotional influences from higher brain areas can override the brainstem’s automatic breathing rhythm

A patient reports repeatedly stopping breathing during sleep (sleep apnea). Using what you know about the control of tidal breathing and competing or reflexive drives, explain (a) which control center normally maintains breathing during sleep, (b) why breathing continues even without conscious effort, and (c) how a breakdown in this control could lead to the clinical picture. Then note one everyday, non-clinical example of one drive overriding another.

A) The medulla in the brainstem is the usual control center for tidal breathing, and breathing during sleep is a passive, involuntary act. 

B) Breathing continues without conscious effort because it helps us maintain homeostasis and operates independently of the upper brain, therefore it does not need to be a conscious  activity.

C) A breakdown in the neurons being sent from the medulla to the diaphragm could cause sleep apnea. 

Which description best captures what the larynx is, before we ever talk about voice?

A. An organ whose only job is producing speech.

B. A fixed bony tube that keeps the airway permanently open.

C. An adjustable air valve positioned vertically between the trachea and pharynx.

 D. A muscle that pumps air into and out of the lungs.

C. An adjustable air valve positioned vertically between the trachea and pharynx.

Which of the following is one of the larynx's three primary biological functions?

A. Digesting food that has entered the throat.

B. Warming and humidifying inspired air.

C. Trapping air in the lungs to stabilize the torso for physical exertion, such as lifting a heavy object.

D. Generating the fundamental frequency of the voice.

C. Trapping air in the lungs to stabilize the torso for physical exertion, such as lifting a heavy object.

what are the larynxs three primary jobs

When we say voice production is a superimposed function of the larynx, we mean that:

A. Sound generation is layered on top of a structure whose first jobs are protecting the airway and body.

B. The larynx must stop protecting the airway whenever it makes sound.

C. Voice was the larynx's original and only purpose.

D. Sound is actually produced elsewhere and merely passes through the larynx.

A. Sound generation is layered on top of a structure whose first jobs are protecting the airway and body.

Which grouping of the laryngeal cartilages is correct?

 A. All of the laryngeal cartilages are paired.

 B. Unpaired: thyroid, cricoid, epiglottis. Paired: arytenoid, corniculate, cuneiform, triticeal.

C. Unpaired: thyroid, arytenoid. Paired: cricoid, epiglottis.

D. Unpaired: arytenoid, corniculate. Paired: thyroid, cricoid.

 B. Unpaired: thyroid, cricoid, epiglottis. Paired: arytenoid, corniculate, cuneiform, triticeal.

Which statement best describes the thyroid cartilage?

A. A single leaf-shaped elastic cartilage tucked behind the root of the tongue.

 B. A complete ring that encircles the airway below the other cartilages.

 C. A pair of small pyramid-shaped cartilages perched on top of the cricoid.

 D. The largest laryngeal cartilage, forming a shield-like housing over the front and sides of the larynx.

 D. The largest laryngeal cartilage, forming a shield-like housing over the front and sides of the larynx.

Why does the adult male larynx typically produce a lower-pitched voice than the adult female larynx?

A. The female larynx simply sits lower in the neck.

B. Men have an extra laryngeal cartilage that women lack.

C. Greater vocal-fold mass raises frequency, so bigger folds mean higher pitch.

D. The male thyroid laminae fuse at a more acute angle (~90° vs ~120° in females), reflecting longer, more massive vocal folds, and frequency is inversely proportional to mass.

D. The male thyroid laminae fuse at a more acute angle (~90° vs ~120° in females), reflecting longer, more massive vocal folds, and frequency is inversely proportional to mass.

The hyoid bone is discussed with the larynx even though it is "technically not part of the larynx." Describe two features that make the hyoid unusual, and explain why it can serve as an anchor for so many muscles.

The hyoid is a free-floating, U-shaped bone: it does not directly attach to any other bone, and its open end faces toward the back (see Hixon p.66). Because it is suspended by a web of muscles and ligaments rather than fixed to a neighboring bone, it is highly mobile and can be pulled in many directions, which lets it act as a movable anchor for the many muscle systems of the tongue and larynx (see Netter p.83).

The laryngeal framework is built of cartilage, bone, ligament, and tendon. State how its flexibility changes from childhood to adulthood, and name the process that stiffens much of the cartilage over time.

The framework is soft and pliable in childhood and becomes hard and more rigid in adulthood (see Hixon p.63). Much of the cartilage is hyaline cartilage, which may calcify with advancing age - the process is called ossification

Name the three types of joints found in the larynx in order of increasing mobility, giving the one-word mobility of each, and name one laryngeal joint that is the most mobile type.

From least to most mobile: the fibrous joint is immobile, the cartilaginous joint is slightly mobile, and the synovial joint is highly mobile

A frontal section through the middle of an adult vocal fold reveals a layered structure. From the airway surface inward, which sequence is correct?

A.Muscle → epithelium → lamina propria → mucosa.

B.A single uniform layer of tissue over muscle.

C.Epithelium → superficial, intermediate, and deep layers of the lamina propria → muscle.

D.  Epithelium → vocal ligament → superficial lamina propria → muscle.

C.Epithelium → superficial, intermediate, and deep layers of the lamina propria → muscle.

The five histological layers regroup into functional units. Which grouping matches the body–cover model?

A. The vocal ligament is the cover and the mucosa is the body.

B. The epithelium alone is the cover and everything below it is the body.

 C. All three lamina propria layers together form the vocal ligament.

 D. The mucosa (epithelium + superficial lamina propria) is the pliable cover, the vocal ligament (intermediate + deep lamina propria) lies between, and the muscle is the body.

D. The mucosa (epithelium + superficial lamina propria) is the pliable cover, the vocal ligament (intermediate + deep lamina propria) lies between, and the muscle is the body.

How do the ventricular (false) vocal folds differ from the true vocal folds?

A. The false folds are the primary vibrators of voice and the true folds only protect the airway.

B.The false folds are muscle-sparse and act as a protective laryngeal valve, while the true folds are the layered vibrating sound source.

C. The opening between the false folds is always narrower than the glottis.

D.The false folds sit below the true folds in the airway.

B.The false folds are muscle-sparse and act as a protective laryngeal valve, while the true folds are the layered vibrating sound source.

The glottis is divided into a membranous portion and a cartilaginous portion. Which statement is accurate?

A. The glottis is the opening between the ventricular folds.

B. The membranous glottis is the back 40% between the arytenoid cartilages.

C. The membranous glottis occupies about 60% of the fold length toward the front; the cartilaginous glottis occupies about 40% toward the back.

TD. he whole glottis is cartilaginous.

B. The membranous glottis is the back 40% between the arytenoid cartilages.

During sustained phonation, what drives each individual open-and-close cycle of the vocal folds?

A. A separate muscle twitch fires to open and close the folds on every single cycle. 

B. Gravity pulls the folds open and shut.

C. The folds vibrate only when the epithelium contracts.

D. Aeromechanical forces — air pressures and airflows — move the positioned folds passively to and fro.

D. Aeromechanical forces — air pressures and airflows — move the positioned folds passively to and fro.

As tracheal pressure rises and pushes the lower part of the folds apart, the glottis takes on a particular shape. What happens across the cycle?

A. The glottis stays a fixed rectangular slit throughout the cycle.

B. The glottis is convergent (wider at the bottom) as the lower folds open, then becomes divergent (narrower at the bottom) as tissue recoil drives them back toward midline.

C.Intraglottal pressure stays constant the whole time.

D.The folds close from the top down first.

B. The glottis is convergent (wider at the bottom) as the lower folds open, then becomes divergent (narrower at the bottom) as tissue recoil drives them back toward midline.

Using the body–cover model, predict how a lesion that adds mass and stiffness to the pliable mucosal cover of the folds would affect voice.

A. It would have no effect, because vibration is powered entirely by muscle twitches.

B. It would only change the false folds, leaving voicing untouched.

C. It would impair the wave-like vibration and closure of the folds, degrading the voice.

 D. It would improve the voice by making the folds firmer.

C. It would impair the wave-like vibration and closure of the folds, degrading the voice.

What single rule sorts a laryngeal muscle into the "intrinsic" versus "extrinsic" group?

A.  Intrinsic muscles have both attachments inside the larynx; extrinsic muscles have one attachment inside and one outside.

B. Intrinsic muscles move the whole larynx; extrinsic muscles tune the vocal folds.

C.Intrinsic muscles are voluntary and extrinsic muscles are involuntary.

 D. Intrinsic muscles are large and extrinsic muscles are small.

A.  Intrinsic muscles have both attachments inside the larynx; extrinsic muscles have one attachment inside and one outside.

Which list correctly names the five intrinsic muscles of the larynx?

A. Only the thyroarytenoid and the cricothyroid.

B. Cricothyroid, cricoarytenoid, geniohyoid, mylohyoid, and arytenoid.

C. Thyroarytenoid, sternothyroid, thyrohyoid, digastric, and cricothyroid.

D.Thyroarytenoid, posterior cricoarytenoid, lateral cricoarytenoid, arytenoid, and cricothyroid.

D.Thyroarytenoid, posterior cricoarytenoid, lateral cricoarytenoid, arytenoid, and cricothyroid.

Which statement about the thyroarytenoid muscle is correct?

A. it is the only abductor of the vocal folds.

B.It attaches outside the larynx, making it an extrinsic muscle.

C. It sits above the vocal folds and rarely contains muscle.

D. It forms most of the mass of each vocal fold and has thyromuscularis and thyrovocalis (vocalis) subdivisions, with the vocal ligament running along the internal edge of the thyrovocalis.

D. It forms most of the mass of each vocal fold and has thyromuscularis and thyrovocalis (vocalis) subdivisions, with the vocal ligament running along the internal edge of the thyrovocalis.

A patient takes a deep breath and the vocal folds swing apart. Which muscle is responsible, and what is special about it?

A.  The posterior cricoarytenoid — it is the only abductor of the vocal folds.

B.The lateral cricoarytenoid — the only abductor.

C. The cricothyroid — the only abductor.

D. The arytenoid muscle — the only abductor.

A.  The posterior cricoarytenoid — it is the only abductor of the vocal folds.

How does the cricothyroid muscle raise vocal pitch?

A. It increases the distance between the thyroid and arytenoid cartilages, which stretches the folds and increases their length and tension.

B. It adds mass to the folds to make them heavier.

C. It shortens the folds by pulling the thyroid and arytenoid cartilages together.

D. It closes the glottis airtight.

A. It increases the distance between the thyroid and arytenoid cartilages, which stretches the folds and increases their length and tension.

Adduction and abduction of the folds arise from rotating the arytenoid cartilages. Which description is correct?

 A. For adduction, the vocal processes rotate medially and inferiorly; for abduction, they rotate superiorly and laterally.

B.  Adduction and abduction come from bending the thyroid cartilage, not rotating the arytenoids.

C. Adduction means the vocal folds get longer.

D. For adduction, the vocal processes rotate superiorly and laterally.

 A. For adduction, the vocal processes rotate medially and inferiorly; for abduction, they rotate superiorly and laterally.

Which statement about the motor innervation of the intrinsic laryngeal muscles is correct?

A. The cricothyroid receives no motor innervation.

B. All intrinsic muscles are supplied by the glossopharyngeal nerve (CN IX).

C. The recurrent laryngeal nerve supplies all intrinsic muscles except the cricothyroid, which is supplied by the external branch of the superior laryngeal nerve.

D. The recurrent laryngeal nerve supplies every intrinsic muscle including the cricothyroid.

C. The recurrent laryngeal nerve supplies all intrinsic muscles except the cricothyroid, which is supplied by the external branch of the superior laryngeal nerve.

When we call laryngeal airway resistance or glottal size a "control variable," what do we mean?

A. It is a fixed anatomical landmark that never changes.

B. It is an adjustable property of the larynx that the nervous system can set higher or lower to change how the larynx behaves.

C. It is a value the clinician measures but the body cannot change.

D. It is a property only used during speech and never during breathing.

B. It is an adjustable property of the larynx that the nervous system can set higher or lower to change how the larynx behaves.

What is the key difference between laryngeal opposing pressure and laryngeal airway resistance?

A. They are two names for the same measurement.

B. Opposing pressure is the net force holding the closed larynx shut; airway resistance is the opposition an open-but-constricted larynx offers to airflow.

C. Airway resistance is largest when the airway is wide open.

D. Opposing pressure applies only when air is flowing fast; resistance applies only when the larynx is sealed.

B. Opposing pressure is the net force holding the closed larynx shut; airway resistance is the opposition an open-but-constricted larynx offers to airflow.

Laryngeal opposing pressure has three components. Which answer lists them and names the biggest contributor?

A. Compressive muscular pressure (the greatest), surface tension between the moist folds, and gravity.

B. Surface tension, gravity, and airway resistance.

C. Airflow, air pressure, and temperature.

D. Gravity alone, which is the greatest contributor.

A. Compressive muscular pressure (the greatest), surface tension between the moist folds, and gravity.

Which change would increase laryngeal airway resistance?

 A. A tighter, longer constriction at the vocal folds, and/or faster airflow through the larynx.

B. Opening the glottis as wide as possible.

C. Slowing the airflow to a trickle at a fixed glottal area.

D. Nothing the folds do changes resistance, since it is fixed.

 A. A tighter, longer constriction at the vocal folds, and/or faster airflow through the larynx.

Which pairing of glottal configuration and the muscles that produce it is correct?

 A. A maximally large glottis comes mainly from posterior cricoarytenoid contraction; airtight closure comes from strong lateral cricoarytenoid and arytenoid muscle activity.

B. A maximally large glottis comes from the lateral cricoarytenoid and arytenoid muscles.

C. A medium glottis requires airtight contraction of all adductors.

D. Glottal size cannot be adjusted once the folds are formed.

 A. A maximally large glottis comes mainly from posterior cricoarytenoid contraction; airtight closure comes from strong lateral cricoarytenoid and arytenoid muscle activity.

The epiglottis folds back to cover the laryngeal aditus during swallowing. What actually moves it?

A. Air pressure from the lungs blows it shut.

B. Its own muscle fibers contract to pull it down.

C. External mechanisms — the aryepiglottic muscles and elevation of the laryngeal housing pressing it against the tongue base — because the epiglottis is cartilage only, with no motive force of its own

C. External mechanisms — the aryepiglottic muscles and elevation of the laryngeal housing pressing it against the tongue base — because the epiglottis is

Why is the movement of the laryngeal housing relevant to safe swallowing?

A.The housing stays perfectly still during swallowing.

B. Only the false vocal folds, never the epiglottis or housing, protect the airway.

C. Housing movement opens the airway wider for food to pass into the lungs.

D. Elevating the housing forces the epiglottis against the tongue base, compressing it back and down over the laryngeal opening to help prevent aspiration.