Term
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Definition
chewing of food
muscle mass involved w/ chewing is greater for closing the mouth (elevation of mandible) than for opening the mouth ( depression the mandible)
Branches of trigeminal nerve (cranial nerve V) innervate them
Temporalis, masseter, medial & lateral pterygoid and digastricus muscles. |
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Term
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Definition
attached to sagittal crest of skull and bulk lies in temporal fossa on either side of cranium.
elevates mandible in order to bring upper and lower arcades of teeth into contact.
well developed in pits and rotts |
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Term
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Definition
arises from maxillary region of head and zygomatic arch to insert on caudal part of mandibl.
acts to elevate mandible & move laterally
well developed in quarter horses. |
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Term
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Definition
medial & lateral pterygoid muscles arise from pterygoid and palatine bones to insert on mandible.
act to close mouth and side to side grinding movements |
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Term
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Definition
arises from an area caudal to the temporomandibular joint and inserts on angle of the jaw.
has 2 bellies and functions to forcibly depress the mandible (open the mouth) |
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Term
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Definition
muscles of facial expression
responsible for movement of skin and appendages of the face and head (nose, lips, eyelids, and ears)
thin, cutaneous muscles innervated by the facial nerve (cranial nerve VII) |
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Term
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Definition
divided into rostral and caudal groups.
actions- responsible for the wide variety of movements that animals can make with their ears.
equine ear muscles- frontoscutalaris M; Interscutalaris M; Cervicoscutalaris M; Zygomaticoscutalaris M; Zygomaticoauricularis M |
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Term
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Definition
| surrounds the palpebral fissure (opening of the eyelids) and is a sphincter like muscle that allows forceful closure of the eyelids. |
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Term
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Definition
| another sphincter like muscle surrounding the margins of the mouth and controlling lip movement. |
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Term
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Definition
| thin muscle that forms the walls of the cheek. |
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Term
| levator nasolabialis muscle |
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Definition
arises from the maxillary bone to the edge of the superior or upper lip. action is to dilate the nostrils and raise the upper lip.
ex: snarling dog |
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Term
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Definition
thin strap muscle that extends from the facial crest in ungulates or the scutiform cartilage of the ear in carnivores to the angle of the mouth.
action- retract the angle of the mouth. |
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Term
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Definition
deep the levator nasolabialis and zygomaticus muscles. inserts on the upper lip in carnivores, ruminants, and swine and on the nostril in equids, ruminants and swine.
action: dilate the nostril and elevate upper lip. |
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Term
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Definition
| extends from the lateral aspect of the body of the mandible to the lower lip. acts to stiffen lower lip. |
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Term
| Muscles of pharynx that aid directly with deglutition or swallowing |
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Definition
Cricopharyngeus
Thyropharyngeus
Hyopharyngeus
Palatopharyngeus
Pterygopharyngeus
Levator veli palatini
Tensor veli palatini |
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Term
| muscles of larynx are involved with phonation (voice) |
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Definition
Cricothyroid M
Cricoarytenoideus dorsalis and lateralis Mm
thyroarytenoideus M
vocalis M |
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Term
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Definition
branches of vagus nerve (cranial nerve X) that leave the vagus at base of the heart and course cranially to innervate the larynx.
condition of "roaring" in horses is result of paresis or paralysis of laryngeal muscles resulting from damage to one of the recurrent laryngeal nerves. Usually its damage to the left one as it is longer of the two. |
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Term
| Intrinsic muscles of the tongue |
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Definition
w/in tongue itself and arranged in fascicles in various planes to allow movement and shape changes of tongue. need not be named as separate muscles.
Frenulum of tongue |
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Term
| extrinsic muscles of tongue |
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Definition
arise outside of the tongue & innervated by hypoglossal nerve (cranial nerve XII).
genioglossus muscle attaches to the rostral mandible and base of tongue. allows tongue to be pulled rostrally.
hyoglossus muscles: attaches to hyoid apparatus and base of tongue to allow tongue to be drawn caudally.
styloglossus muscle: attaches to the stylohyoid bone and middle of tongue to retract and elevate the tongue. |
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Term
The hyoid muscles
sternohyoideus muscle
thyrohyoideus muscle |
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Definition
associated with hyoid apparatus. Fxn- swallowing.
sternohyoideus muscle arises from sternum and first costal cartilage to insert on the basihyoid bone.
thyrohyoideus muscle is short and is dorsal to sternohyoideus, extending from the thyroid cartilage of the larynx to the thyrohyoid bone of the hyoid apparatus.
both muscles innervated by hypoglossal nerve. |
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Term
The hyoid muscles
mylohyoideus muslce
geniohyoideus muscle |
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Definition
mylohyoideus muscle- thin muscle b/t intermandibular space. aids in support of tongue and is innervated by mandibular nerve (branch of trigeminal nerve or cranial nerve V)
Geniohyoideus muscle- strap muscle from the mandibular symphysis to the basihyoid bone. acts to draw the hyoid apparatus and larynx rostrally. hypoglossal nerve innervates it. |
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