The Head Flashcards
Which muscle’s only action is to open the glottis?
cricoarytenoideus dorsalis
What is common in small and large animal medicine and commonly occurs on the left side?
Laryngeal Paralysis
What innervates the cricothyroid muscle?
cranial laryngeal nerve (a branch off the vagus nerve)
What are the cricoarytenoideus dorsalis and lateralis and the thyroarytenoideus muscles innervated by?
caudal laryngeal nerve (a branch off the recurrent laryngeal nerve)
What happens if innervation to the cricoarytenoideus dorsalis is damaged (stops)?
the resulting nerve damage causes a lack of abduction of the arytenoid cartilages during inhalation and the glottal opening remains narrowed unilaterally (bilateral if there is bilateral nerve damage).
What is laryngeal hemiplegia?
when only one side of the glottis remains narrowed due to lack of innervation to the cricoarytenoideus dorsalis muscle.
What results from laryngeal hemiplegia?
Increased respiratory sounds, effort on inhalation, and exercise intolerance can result from this condition, due to the narrowed opening of the respiratory tract.
Which species have additional salivary glands? Where are they located?
Cats have additional salivary glands (molar glands) which lie in a small flap of the sublingual fold, immediately adjacent to the lingual aspect of teeth 308 and 408.
What is a sialocele?
a pocket of saliva caused by damage or blockage to a salivary duct
Why is the molar gland relevant to small animal medicine?
Care must be taken during extractions of these teeth not to damage the molar glands, or catch them in a suture while closing tissue over the extraction site, to avoid formation of an iatrogenic sialocele.
What duct is most commonly effected by a sialocele?
parotid duct
How is a sialocele treated?
removal of effected salivary gland
How many muscles are used to open the mouth?
only one
Which palpebral ligament is stouter than the other? When is this apparent?
The medial palpebral ligament is much stouter than the lateral palpebral ligament.This difference is best appreciated during an enucleation (removal of the eyeball and nictitating membrane) when the palpebral ligaments must be cut in order to remove the globe from its surrounding periorbita. The medial palpebral ligament is much more developed and thus requires more effort to incise.
What happens when a dog blinks?
- palpebra sweeping over globe cause corneal reflex -> retractor bulbi muscles contract and pull eye caudally into orbit
- as eye is pulled caudally, nictitating membrane (third eyelid) sweeps over anterior surface of eye
