Head Muscles Flashcards
What are the muscles of the head in the horse (that we need to know)?
levator nasolabialis, caninis, levator labii superioris, zygomaticus, depressor labii inferioris, malaris
What is the origin of the levator nasolabialis in the horse?
frontal and nasal bones
In the horse, what does the levator nasolabialis do before it inserts?
it splits into a dorsal and ventral branch
In the horse, what does the dorsal branch of the levator nasolabialis insert on?
the upper lip and the lateral wing of the nostril
In the horse, what does the ventral branch of the levator nasolabialis insert on?
the commissure of the lips
What is the function of the levator nasolabialis?
elevates the upper lip and comissure and dilates the nostril
In the horse, what is the origin of the caninis?
maxilla near the facial crest
In the horse, what is the insertion of the caninis?
lateral wing of the nostril
What is the course of the caninis in the horse?
courses in between both branches of the levator nasolabialis
What is the function of the caninis?
dilates the nostril
In the horse, what is the origin of the levator labii superioris?
the junction of the lacrimal, zygomatic, and maxillary bones
In the horse, where does the levator labii superioris insert?
on the upper lip via the same tendon
What is the function of the zygomaticus?
it retracts and elevates the angle of the mouth
In the horse, what is the origin of the depressor labii inferioris?
alveolar border of the mandible
In the horse, what is the insertion of the depressor labii inferioris?
the lower lip
What is the function of the depressor labii inferioris?
depresses and retracts the lower lip
For nerve blocking in the horse, what facial muscles need to be pushed out of the way?
the levator labii superioris and depressor labii inferioris
What are the facial muscles of the ruminant?
levator nasolabialis, levator labii superioris, caninis depressor labii superioris, zygomaticus, malaris and depressor labii inferioris
In the ruminant, what is the origin of the levator nasolabialis?
rostral part of the frontal bone and frontalis muscle
In the ruminant, what does the levator nasolabialis do after its origin?
divides into superficial and deep portions
In the ruminant, where does the superficial part of the levator nasolabialis insert?
nostril and upper lip
In the ruminant, where does the deep part of the levator nasolabialis insert?
lateral nasal cartilages, incisive bone, and lateral part of the nostril
In the ruminant, what is the origin of the levator labii superioris?
the facial tuberosity
In the ruminant, what is the insertion of the levator labii superioris?
the muzzle
What is the course of the levator labii superioris in the ruminant?
it courses between the two portions of the levator nasolabialis muscle
In the ruminant, what is the function of the levator labii superioris?
elevates the lip
In the ruminant, what is the origin of the caninis?
the facial tuberosity
In the ruminant, what is the insertion of the caninis?
the lateral portion of the nostril
Where does the caninis course in the ruminant?
between the two portions of the levator nasolabialis
In the ruminant, what is the origin of the depressor labii superioris?
maxilla and facial tuberosity
In the ruminant, what is the insertion of the depressor labii superioris?
the upper lip and ventral portion of the nostril
What is the function of the depressor labii superioris in the ruminant?
retracts the rostral portion of the upper lip and the ventrolateral portion of the nostril
In the ruminant, how is the malaris structured?
it has both rostral and caudal parts
What is the origin and insertion of the rostral portion of the malaris?
O: facial part of the lacrimal bone
I: buccal fascia dorsal to the buccinator
In the ruminant, what is the function of the rostral portion of the malaris?
it raises the caudal part of the cheek
What is the origin and insertion of the caudal portion of the malaris?
O: masseteric fascia
I: lower eyelid
In the ruminant, what is the function of the caudal portion of the malaris?
Depresses the lower eyelid and widens the palpebral fissure
