Lecture 16/17 10/24/24 Flashcards

1
Q

What are the functions of the upper airway in horses?

A

-olfaction
-phonation
-deglutition
-thermoregulation
-filtering
-conditioning inspired air
-protection of lower airway from aspiration
-conduit of airflow to and from lung

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2
Q

What are the anatomical considerations regarding the upper airway of the horse?

A

-large dead space volume
-high resistance to flow
-tends to collapse in response to neg. pressure generated during inspiration

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3
Q

What is the limiting factor in a horse’s exercise capacity?

A

upper airway

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4
Q

What is the tidal volume and minute ventilation in a horse at rest?

A

tidal vol: 5L
minute ventilation: 75 L

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5
Q

How does exercise impact a horse’s tidal volume and minute ventilation?

A

increases it 20-fold

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6
Q

What is impedance?

A

-ratio of driving pressure and resulting airflow
-measure of how much airflow is opposed by the respiratory system

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7
Q

What are the characteristics of impedance on inspiration and expiration?

A

-impedance is 2x as high on inspiration
-sub-atmospheric intraluminal pressures cause airway to narrow on inspiration
-positive intraluminal pressures enlarge airway diameter during exhalation

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8
Q

What is the importance of the Bernoulli effect?

A

reducing the radius by 1/2 increased resistance by 16 fold

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9
Q

What is a progressive ethmoidal hematoma?

A

-encapsulated, expansive, distorting, and destructive mass
-usually originates within ethmoid turbinate

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10
Q

Where might a progressive ethmoidal hematoma expand into?

A

-nasal passages
-pharynx
-paranasal sinuses

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11
Q

What are the clinical signs of a progressive ethmoidal hematoma?

A

-hemorrhagic or serosanguineous unilateral nasal discharge that is intermittent and not associated with exercise
-respiratory noise
-unequal airflow
-fetid breath
-facial distortion
-coughing/choking
-hematoma at external nares
-possible for horse to be affected bilaterally

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12
Q

What is a cleft palate?

A

incomplete cleft that can impact the hard and soft palate

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13
Q

What is the most common cleft palate presentation?

A

incomplete cleft of the soft palate that involves the caudal half to two-thirds of the structure

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14
Q

In which direction do the embryonic palatal folds fuse in a cleft palate?

A

rostral to caudal

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15
Q

What is aryepiglottic fold entrapment?

A

aryepiglottic folds become dorsally displaced
-fold covers tip of epiglottis and entraps it
-folds of mucous membrane tissue expand when epiglottis is elevated during deglutination

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16
Q

What is dorsal displacement of the soft palate?

A

-soft palate is displaced dorsally during swallowing
-epiglottis covers the adducted arytenoid cartilages and vocal folds
-intermittent or persistent malpositioning of the caudal edge of soft palate dorsal to epiglottis

17
Q

What are the clinical signs of continuous dorsal displacement of the soft palate?

A

-continual emission of rumbling noise that is greatest on expiration
-bulging of cheeks from mouth breathing
-cough
-bilateral nasal discharge when eating
-epiglottic abnormality
-may occur after strangles or guttural pouch infection

18
Q

What are the clinical signs of intermittent dorsal displacement of the soft palate?

A

-may only occur during strenuous exercise
-intermittent noise production that is greatest during expiration
-mouth breathing
-excessive salivation
-bulging of cheeks
-coughing
-swallowing

19
Q

How is dorsal displacement of the soft palate diagnosed?

A

-history/clinical signs
-endoscopy

20
Q

What is the goal of treatment for dorsal displacement of the soft palate?

A

alleviate any primary disease of the upper respiratory tract that could cause the DDSP

21
Q

What are the treatment options for dorsal displacement of the soft palate?

A

-tying the tongue
-sclerotherapy
-surgical removal of caudal free border of soft palate
-sternothyrohyoidectomy

22
Q

What is recurrent laryngeal hemiplegia?

A

-neurogenic atrophy of intrinsic muscles of the larynx
-secondary to neuropathy of motor neurons in the recurrent laryngeal nerve

23
Q

Which side of the larynx is most commonly affected in recurrent laryngeal hemiplegia?

A

left side

24
Q

What are the characteristics of muscular innervation in the larynx?

A

-recurrent laryngeal nerve innervates all intrinsic muscles of the larynx except one
-cricothyroideus muscle is NOT innervated by recurrent laryngeal nerve

25
Q

How is recurrent laryngeal hemiplegia diagnosed?

A

-complaint of exercise intolerance
-rasping roar on inspiration during exercise
-physical exam to rule out other causes
-palpation of larynx
-long, loud grunt and sigh when threatened with a stick
-inability to neigh properly/hoarseness
-endoscopic examination

26
Q

What are the treatment options for recurrent laryngeal hemiplegia?

A

surgery:
-ventriculectomy: adherence of vocal fold to lateral larynx wall
-prosthetic laryngoplasty: mimic permanent contraction of muscle with suture
-arytenoidectomy
-laryngeal re-innervation

27
Q

What is chondropathy of the arytenoid cartilage?

A

chronic inflammation of the arytenoid cartilage that results in deformity, ossification, and immobility

28
Q

What are the clinical signs of chondropathy of the arytenoid cartilage?

A

-inspiratory difficulty during exercise that may progress to difficulty at rest
-inspiratory noise produced during exercise and eventually at rest
-equal distribution between right and left sides

29
Q

How is chondropathy of the arytenoid cartilage treated?

A

arytenoidectomy:
-total: entire cartilage removed
-subtotal: corniculate and muscular processes are not removed
-partial: entire cartilage except muscular process is removed

30
Q

Which teeth are not associated with any sinus?

A

-premolar 2 (#6)
-premolar 3 (#7)

31
Q

What are the characteristics of premolar 4/#8?

A

-rostral roots are not in a sinus
-caudal roots are in the rostral maxillary sinus

32
Q

What are the characteristics of molar 1/#9?

A

-all roots are in the rostral maxillary sinus
-oldest tooth in head
-most commonly associated with problems

33
Q

What are the characteristics of molar 2/#10?

A

-rostral roots are in rostral maxillary sinus
-caudal roots are in caudal maxillary sinus

34
Q

What are the characteristics of molar 3/#11?

A

all roots are in the caudal maxillary sinus