Masticatory, Lingual, Hyoid muscles and the Eye

Question 1

Temporalis muscle

Answer 1

origin: temporal fossa
insertion: coronoid process of the mandible
action: Raise mandible (Shut the jaw)
innervation: Mandibular division of the trigeminal n.

Question 2

Masseter muscle

Answer 2

origin: zygomatic arch
insertion: masseteric fossa, the ventrolateral surface of the ramus of the mandible, and the angular process
action: Raise mandible (Shut the jaw)
innervation: Mandibular division of the trigeminal n.

Question 3

Pterygoid muscle

Answer 3

medial and lateral;

origin: pterygopalatine fossa
insertion: medial surface and caudal margin of the ramus of the mandible and angular process, ventral to the insertion of the temporal muscle
action: Raise mandible (Shut the jaw)
innervation: Mandibular division of the trigeminal n.

Question 4

Digastricus muscle

Answer 4

divided into rostral and caudal parts

origin: paracondylar process of the occipital bone
insertion: body of the mandible
action: opens the jaws
innervation: rostral part- mandibular nerve (branch of cranial nerve V), caudal- facial nerve (CN VII)

Question 5

Zygomatic salivary gland

Answer 5

between the eyeball and pterygoid muscles; hidden laterally bu the zygomatic bone; opens into the vestibule by one main and several minor ducts lateral to the last superior molar tooth

Question 6

Styloglossus muscle

Answer 6

origin: stylohyoid bone
insertion: middle of the tongue
action: Lift and draw tongue caudal (Move tongue)
innervation: Hypoglossal n.

Question 7

Hyoglossus muscle

Answer 7

origin: thyrohyoid and basihyoid
insertion: root of the tongue
action: Depress and draw tongue caudal (Move tongue)
innervation: Hypoglossal n.

Question 8

Genioglossus muscle

Answer 8

origin: intermandibular articulation and adjacent surface of the body of the mandible
insertion: body of the tongue
action: Depress and protrude tongue, retract apex (Move tongue)
innervation: Hypoglossal n.

Question 9

Sternohyoid muscle

Answer 9

origin: sternum and first costal cartilage
insertion: basihyoid bone
action: Draw tongue and larynx caudally
innervation: Cervical spinal nn.

Question 10

Thyrohyoid muscle

Answer 10

origin: thyroid cartilage of the larynx
insertion: thyrohyoid bone
action: Draw hyoid apparatus caudally
innervation: Hypoglossal n. (CN XII)

Question 11

Geniohyoid muscle

Answer 11

origin: on and adjacent to the intermandibular articulation
insertion: basihyoid bone
action: Draw hyoid apparatus and larynx rostrally
innervation: Hypoglossal n. (CN XII)

Question 12

Periorbita

Answer 12

cone shaped sheath of connective tissue and smooth muscle that encloses the eyeball and its muscles, vessels, and nerves

Question 13

Lacrimal gland

Answer 13

small, flat lobular structure lying on the medial side of the orbital ligament within the periorbita

Question 14

Levator palpebrae muscle

Answer 14

origin: apex of the orbit
insertion: as a flat tendon in the upper eyelid
action: Raise upper eyelid
innervation: Oculomotor n. (CN III)

Question 15

Dorsal oblique muscle

Answer 15

insertion: trochlea
action: Rotation of eye, dorsal part towards midline
innervation: Trochlear n.

Question 16

Ventral oblique muscle

Answer 16

origin: rostral border of the palatine bone at the level of the maxillary foramen
insertion: sclera at the insertion of the lateral rectus
action: Rotation of eye, ventral part toward midline (opposes action of the dorsal oblique m.)
innervation: Oculomotor n.

Question 17

Dorsal Rectus muscle

Answer 17

origin: small area around optic canal and optic fissure
insertion: sclera
action: Upward movement of eye
innervation: Oculomotor n.

Question 18

Lateral Rectus muscle

Answer 18

origin: small area around optic canal and optic fissure
insertion: sclera
action: Abduction of the eye
innervation: Abducent n.

Question 19

Medial Rectus muscle

Answer 19

origin: small area around optic canal and optic fissure
insertion: sclera
action: Adduction of the eye
innervation: Oculomotor n.

Question 20

Ventral Rectus muscle

Answer 20

origin: small area around optic canal and optic fissure
insertion: sclera
action: Downward movement of the eye
innervation: Oculomotor n.

Question 21

Retractor bulbi muscles

Answer 21

sit within the rectus muscles and surround the optic nerve

action: Retraction of eye
innervation: Abducent n.

Question 22

Trochlea

Answer 22

cartilaginous plaque attached at the level of the medial angle of the eye to the wall of the orbit

Question 23

Cornea

Answer 23

part of the external fibrous coat, anterior one fourth, transparent, avascular

Question 24

Sclera

Answer 24

part of the external fibrous coat; forms the posterior three fourths, opaque, vascular

Question 25

Limbus

Answer 25

corneoscleral junction

Question 26

Iris and Pupil

Answer 26

iris: circular and radial smooth muscle; pigmented diaphragm with a central opening (pupil)

Question 27

Mylohyoid muscle

Answer 27

origin: medial surface of the body of the mandible
insertion: midventral raphe; basihyoid bone
action: Draw hyoid apparatus cranially, lift floor of the mouth
innervation: Mandibular division of the trigeminal n.