The Hyoid, Larynx And Swallowing Flashcards
What is the hyoid apparatus? Which bones are they?
5 bones associated with the larynx
Stylohyoid, epihyoid, keratohyoid, thyrohyoid, basihyoid
Are the hyoid bones paired or unpaired?
All paired except basihyoid
The thyrohyoid is attached to what cartilage?
The thyroid cartilage
Which 4 muscles are associated with the hyoid apparatus?
Sternohyoideus
Thyrohyoideus
Mylohyoideus
Geniohyoideus
Which nerve innervates the thyrohyoideus and sternohyoideus? What is their function?
Cervical nerve
Draw hyoid causally
What is the innervation and action of the mylohyoid?
Trigeminal
Draw hyoid rostrally
What is the innervation and action of the geniohyoideus?
Hypoglossal nerve
Draw hyoid rostrally
Why is the larynx hard to see on the radiograph of younger animals?
Less calcified
What is the primary and secondary function of the larynx?
Protect lower respiratory tract from foreign bodies
Vocalisation
What type of tissue makes up the larynx? What does the hyoid apparatus do in terms of the larynx?
Cartilaginous and smooth muscle tube
Suspends larynx from skull
What is the vestibule of the larynx? What is its entrance called?
Funnel shaped part,ventral floor is the epiglottis
Lies rostrally
Laryngeal aditus
What are the cartilages of the larynx?
Thyroid
Epiglottis
Arytenoid
Cricoid
Are the cartilages of the larynx paired or unpaired?
All unpaired except arytenoid
What shape is the arytenoid cartilage? What shape is the cricoid cartilage?
2 horned
Ring - thicker at top
Does nasal breathing take place above or below the soft palate?
Above
What is the vestibular fold?
The mucosal fold at the end of the vestibule
What is the vocal fold? What is it’s function?
The vocal chord - vocalisation
What is the aryepiglottic fold?
Mucosal fold from arytenoid to epiglottis
How many pairs of muscles open the glottis? How many pairs open it?
7 pairs close
1 pair open
What is the function of the cricoarytenoideus dorsalis? IMPORTANT
Abducts arytenoid
Opens glottis
Which is the only muscle to open the glottis?
Cricoarytenoideus dorsalis
Give one example of a muscle which closes the glottis and innervation
Cricoarytenoideus lateralis Laryngeal nerve (runs up trachea)
What is the laryngeal saccule? What is it’s opening called?
Pocket in the larynx
Laryngeal ventricle of larynx
Brachycephalic dogs often need ventriculotomy. Why is this?
Laryngeal saccule eversion (closes on itself - struggle to breathe)
Which nerves supply the larynx
Vago-accessory complex
Cranial laryngeal nerve (AE, VE, SVE)
Recurrent laryngeal nerve (AE,EE, SVE)
Roaring in horses is due to what? How is this caused? What is the solution?
Laryngeal collapse
Paralysis of cricoarytenoideus dorsalis
Surgery - suture arytenoid cartilage open
The larynx is very sensitive and reflexes. Why might local anaesthetic be needed when tubing an animal before an operation?
Irritation causes coughing and closure of the glottis
When swallowing, what happens?
Tongue squeezes bolus
Glottis closes
Hyoid apparatus swings forward
And reverses
The swallowing reflex is innervates by which nerve for afferent and efferent?
Afferent - glossopharyngeal, vagus
Efferent - vago-accessory complex
