Gross - Spring - Equine And Ruminant Larynx - Mt1

Front 1

Does the horse or ruminant have the cuneiform process? How is the cuneiform cartilage different from the dog?

Back 1

The horse and dog are the only species with a cuneiform process, the ruminant does not. This cuneiform process is fused to the epiglottic cartilage, not the arytenoid cartilage like in the dog.

Front 2

Is the epiglottis hyaline or elastic? What about the thyroid/cricoid cartilages?

Back 2

Epiglottis is elastic
The others are hyaline cartilage.

Front 3

Do the equine corniculate cartilages curve cranially or caudally?

Back 3

Caudally, as in the dog.

Front 4

Is the body of the thyroid cartilage larger in the ox or horse? What is the clinical signifigance?

Back 4

Larger in the ox. Signifigant because the caudal notch can be used as a surgical approach to the larynx in the horse.

Front 5

What is the condition that involves the muscle extending from the median crest of the equine cricoid cartilage? What is that muscle?

Back 5

Laryngeal hemiplegia
cricoarytenoideus dorsalis m.

Front 6

What is 3 in this ox larynx?

Back 6

Corniculate processes of the arytenoid cartilage

Front 7

Name these

Back 7

this one has mucosa on it

Front 8

In small animals, we called 5 the laryngeal ventricle. What should we be prepared to call it in the horse?

Back 8

Lateral laryngeal ventricle

Front 9

Do ruminants have lateral laryngeal ventricles?

Back 9

No

Front 10

Do ruminants have vestibular folds?

Back 10

No

Front 11

What makes up the vocal fold in the ox?

Back 11

Covers the vocal ligament and underlying part of thyroarytenoideus m.

Front 12

What makes up the aryepiglottic fold in the ox?

Back 12

From lateral border of epiglottic cartilage to corniculate process of arytenoid

Front 13

What is the entrance to the larynx called in the horse?

Back 13

Aditus laryngis

Front 14

What are the three areas of the laryngeal cavity of the horse?

Back 14

Vestibule, glottic cleft, infraglottic cavity

Front 15

What is the action of sternothyroideus m?

Back 15

Pulls larynx caudally

Front 16

What is the action of the hyoepiglotticus?

Back 16

Pulls the epiglottis toward the basihyoid bone.

Front 17

Where does cricothyroideus m. course between in the horse? What is its action?

Back 17

Arises from the lateral surface and caudal edge of the cricoid cartilage
Inserts on the caudal border and adjacent part of the lateral surface of the thyroid lamina
Narrows glottic cleft; tenses vocal folds

Front 18

Where does the arytenoideus transversus m. course between in large animals? What is its action?

Back 18

Courses transversely across the dorsal surface of the larynx and attaches to the muscular processes of the arytenoid cartilages
Narrows glottic cleft by drawing the arytenoid cartilages together (adduction

Front 19

Where does the cricoarytenoideus dorsalis m. course between in large animals? What is its action? What innervates it?

Back 19

Arises from the lamina and median ridge of the cricoid cartilage
Inserts on the muscular process of the arytenoid cartilage
Enlarges the glottic cleft by rotating the arytenoid cartilage so that the vocal process moves laterally (abduction)

Innervated by the recurrent laryngeal n.

Front 20

Where does the cricoarytenoideus lateralis m. course between in large animals? What is its action?

Back 20

Arises from the rostral border of the cricoid arch
Inserts on the muscular process of the arytenoid cartilage
Narrows the glottic cleft by rotating the arytenoid cartilage medially (adduction)

Front 21

What three muscles in the equine close the glottis?

Back 21

Ventricularis, vocalis (thyroarytenoideus m.) and cricoarytenoideus lateralis muscles pull the muscular process of the arytenoid cartilage ventrally. Arytenoideus transversus muscle draws the arytenoid cartilages together

Front 22

What muscle in the equine opens the glottis?

Back 22

Cricoarytenoideus dorsalis muscle pulls the muscular process dorsocaudally, rotating the arytenoid so that the vocal process and fold are pulled laterally

Front 23

If you saw this when intubating, what would you think?

Back 23

Dorsal displacement of the soft palate in the horse

Front 24

If you saw this when intubating, what would you think?

Back 24

Epiglottic entrapment in the horse

Front 25

If you saw this when intubating a horse, what would you think?

Back 25

You'd think - awesome - this is the normal position of epiglottis during breathing.

Front 26

Where does the ventricularis m. in the horse course between? What are its actions?

Back 26

Arises from the medial surface of the rostral part of the thyroid lamina and from a small part of the cricothyroid membrane
Inserts dorsally on the muscular process of the arytenoid cartilage
Narrows the glottic cleft

Front 27

Where does the vocalis m. course between? What is its action?

Back 27

Arises from the body of the thyroid cartilage
Inserts on the muscular process of the arytenoid cartilage
Narrows the glottic cleft

Front 28

Where does thyroarytenoideus m. course between in the ruminant?

Back 28

Not divided into vocalis and ventricularis mm. in the ruminant
Arises ventrally from the basal part of the lateral border of the epiglottis, the medial surface of the thyroid lamina and from the cricothyroid membrane
Inserts on the vocal and muscular processes of the arytenoid cartilage

Front 29

What muscles do the recurrent laryngeal n. and cranial laryngeal n. innervate?

Back 29

Recurrent laryngeal n.
Innervates all intrinsic laryngeal muscles except the cricothyroideus m.
Sensory to the mucous membrane of the caudal portion of the larynx

Cranial laryngeal n.
Innervates the cricothyroideus m.
Sensory to the mucous membrane of the cranial portion of the larynx

Front 30

What feature of the large animal pharynx allows saliva to pass the larynx without swallowing?

Back 30

Piriform recess

Front 31

Follow the pathway of air from the nasal cavity through to the trachea in the large animal.

Back 31

1 Nasal cavity
2 Oral cavity
3 Soft palate
4 Nasopharynx
5 Root of tongue
6 Larynx
7 Laryngopharynx
8 Caudal end of palatopharyngeal arch
9 Esophagus
10 Cricoid cartilage
11 Trachea

Front 32

Name these numbered structures of the equine larynx.

Back 32

1 Epiglottis
2 Laryngeal entrance
3 Pharyngeal recess
4 Auditory tube opening

Front 33

What are one and two of this equine larynx? What would you see in roarings?

Back 33

1 Arytenoid cartilage
2 Left and right vocal folds

In roarings you’ll see the arytenoid adducting, instead of normally abducted.

Front 34

What is the difference between a horse and a ruminant hyopharyngeus m.?

Back 34

The horse hyopharyngeus m. arises from the thyrohyoid bone and thyroid lamina.

The ruminant hyopharyngeus m. arises from the thyrohyoid, ceratohyoid, and stylohyoid bone.

Front 35

Where does the hyoepiglotticus m. course from in the horse vs the ruminant?

Back 35

It courses from the basihyoid bone in the horse and the ceratohyoid bone in the ruminant.