facial muscles

Question 1

Platysma m.

Answer 1

origin dorsal median raphe of the neck

insertion: angle of the mouth; also inserts over orbiculares oris m.
innervation: dorsal and ventral buccal branches of facial n.
action: draw commissure of lips caudally

Question 2

orbicularis iris m.

Answer 2

located along free border of the lips around the angle of the mouth
innervated by dorsal and ventral buccal brs. of facial n.
action: close mouth opening
pull nose downward during sniffing
dilate nostril

Question 3

buccinator m.

Answer 3

attachments: alveolar borders of the mandible and maxilla and buccal mucosa
innervation: Dorsal and ventral buccal brs. of facial n.
action: : move food from the vestibule to the masticatory surface of the teeth

Question 4

levato nasolabialis m.

Answer 4

origin: frontal region between the orbits and maxillary bone
insertion: edge of upper lip and external nostril
innervation: auriculopalpebral br. of facial n.
action: dilate nostril and raise upper lip

Question 5

zygomaticus m.

Answer 5

origin: rostral border of the scutiform cartilage
insertion: commissure of lip
innervation: auriculopalpebral br. of facial n.
action: draw the commissure of the mouth dorsocaudally; draw the scutiform carriage and ear rostrally

Question 6

parotidoauricularis m.

Answer 6

origin: caudal to the laryngeal region, on or near the ventral midline
insertion: antitragus of the ear
innervation: facial n.
action: depresses ear

Question 7

orbicularis oculi m.

Answer 7

encircles the eye
closes the palpebral fissure
innervated by palpebral brs. of auriculopalpebral br. of facial nerve

Question 8

retractor angel oculi lateralis m.

Answer 8

covers the lateral palpebral ligament
retracts the lateral angle of eye caudally (causes eye to squint)
innervated by palpebral brs. of auriculopalpebral br. of facial nerve

Question 9

levator anguli oculi medialis m.

Answer 9

located dorsomedial to the eye
raises the eyelid
innervated by palpebral brs. of auriculopalpebral br. of facial nerve