Lecture 4.3 - Muscles of eyes, mastication, soft palate, and tongue

Question 1

What is a lacrimal apparatus?

Answer 1

the path of a tear from the lacrimal gland to the nasal cavity

• lacrimal gland produces tear (parasympathetic from facial nerve)
• lacriman ducts, surface of eye, lacrimale lake/puncta/canaliculi/sac, nasolacrimal duct, nasal cavity inferior to the inferior concha

Question 2

What are the muscles of eye movement?

Answer 2

• 6 ocular muscles move the eyeball – 4 straight and 2 oblique
• the 4 rectus muscles arise by a common tendinous ring

Question 3

Where does the tendon of superior oblique muscles run through?

Answer 3

• through a fibrocartilaginous loos called trochlea and then inserts into the sclera of eyeball

Question 4

Inferior oblique eye muscle (OINA)

Answer 4

O: orbital plate of maxilla
I: sclera of eye
N: Oculomotor
A: elevates and laterally deviates gaze

Question 5

Superior oblique eye muscle (OINA)

Answer 5

O: common tendinous ring
I: sclera of eye
N: trochlear
A: depresses and laterally deviates gaze

Question 6

Inferior Rectus eye muscle (OINA)

Answer 6

O: common tendinous ring
I: sclera of eye
N: oculomotor
A: depresses and medially deviates gaze

Question 7

Lateral Rectus eye muscle (OINA)

Answer 7

O: common tendinous ring
I: sclera of eye
N: abducens
A: laterally deviates gaze

Question 8

Media Rectus eye muscle (OINA)

Answer 8

O: common tendinous ring
I: sclera of eye
N: oculomotor
A: medially deviates haze

Question 9

Superior Rectus eye muscle (OINA)

Answer 9

O: common tendinous ring
I: sclera of eye
N: oculomotor
A: elevated and medially deviates gaze

Question 10

What are the extraocular muscle functions?

Answer 10

• once the eye is adducted, the superior and inferior obliques work best to lower and raise the eye
• once the eye is abducted, the superior and inferior recti work best to raise and lower the eye

Question 11

What muscles are needed to look directly upwards?

Answer 11

both superior rectus and inferior oblique

Question 12

What muscles are needed to look directly down?

Answer 12

both inferior rectus and superior oblique

Question 13

What are the characteristics of the trigeminal nerve and its 3 branches?

Answer 13

• main sensory nerve for head
• motor nerve for the muscles of mastication
• 3 large branches:
• • to the area above and media to the eye (sensory)
• • the the maxillary region (sensory)
• • to the mandibular region (sensory and motor)

Question 14

What happens if there is a lesion in the trigeminal nerve?

Answer 14

• causes anesthesia of corresponding areas of scalp, face, cornea, conjunctiva, nose, mouth and tongue and also paralysis of muscles of mastication; when mouth is opened mandible moves to paralyzed side

Question 15

Temporalis (OIA)

Answer 15

O: floor of temporal fossa
I: coronoid process of mandible
A: anterior and posterior fibers elevate mandible; posterior fibers retract mandible

Question 16

Masseter (OIA)

Answer 16

O: zygomatic arch
I: lateral surface of mandible
A: elevates and protrudes mandible; deep fibers retrude mandible

Question 17

Medial pterygoid (OIA)

Answer 17

O: tuberosity of maxilla and lateral pterygoid plate
I: medial surface of angle of mandible
N: elevates and help protrude mandible

Question 18

Lateral pterygoid (OIA)

Answer 18

O: upper head: greater wing of sphenoid; lower head: lateral pterygoid plate
I: neck of mandible and articular disc, capsule of TM jiont
A: protrude mandible and produce side-to-side movement

Question 19

What muscles are used in protraction/retraction of jaw?

Answer 19

Protraction: lateral pterygoid, little bit of medial pterygoid, masseter
Retraction: posterior fibers of temporalis, deep part of masseter, geniohyoid, digastric

Question 20

What is the temporomandibular joint (TMJ)?

Answer 20

formed by head of mandible, mandibular fossa, and articular tubercle of temporal bone

Question 21

What muscles are used in elevation and depression of jaw?

Answer 21

Elevation: (biting movement) temporalis, masseter, medial pterygoid
Depression gravity, lateral pterygoid, digastric, geniohyoid, mylohyoid

Question 22

What muscles contracts when move the mandible to one side?

Answer 22

• temporal of same side
• medial/lateral pterygoid of opposite side
• masseter of same side

Question 23

What kind of joint is the TMJ?

Answer 23

• hinge and gliding joint
• forward gliding and hinge-like rotation
• when the mouth is opened, the head and the articular disc move forward until the head lies inferior to the articular tubercle

Question 24

What is the muscle movement at the TMJ?

Answer 24

• lateral pterygoid pulls head of mandible anteriorly
• head (condyle) and articular disc slide anteriorly
• occurs when mouth opens a lot
• wears on the bone and/or cartilage can cause pain
• can be confused with ear pain

Question 25

How is the TMJ dislocated and its symptoms?

Answer 25

- TMJ is easily dislocated - usually dislocates anteriorly, especially when yawning or taking a large bite - the person is then unable to close the mouth - also dislocated during tooth extraction or by a blow to the chin when mouth is open (usually bilateral)

Question 26

How is the TMJ damage occured?

Answer 26

- powerful compressive forces act on TMJ - can occur from: - - frequently chewing gum - - frequently chewing heard foods like nuts, hard vegetables, toothpicks - - grinding teeth - - nail biting

Question 27

Which muscles elevate mandible and close mouth?

Answer 27

temporalis, masseter, and medial pterygoid

Question 28

Which muscles pull mandible anteriorly and opens mouth?

Answer 28

lateral pterygoid and anterior belly of the digastric

Question 29

Which muscles tenses the floor and roof of mouth

Answer 29

mylohyoid and tensor veli palatini

Question 30

What does the oral palate form? What does it consist of?

Answer 30

- forms the roof of the mouth and floor or nasal cavity. - consists of: - - hard palate: anterior, immobile - - soft palate: posterior, mobile, tip of uvula

Question 31

What is the hard palate formed by?

Answer 31

- the palatine process of maxillae and horizontal process of palatine bones; it is arched

Question 32

What are the muscles of the soft palate?

Answer 32

- also called velum palatinum - tensor veli palatini - - tenses soft palate, opens pharyngotympanic tube, CN V3 - levator veli palatini - - elevates soft palate, CN X

Question 33

Function and innervation of uvular, palatopharyngeus, and palatoglossus?

Answer 33

- Uvular elevates uvula, CN X - Palatopharyngeus elevates pharynx, CN X - Palatoglossus elevates tongu, CN X

Question 34

What are the extrinsic muscles of tongue with function and innervation?

Answer 34

- all innervated by CN XII - Styloglossus retracts and elevates tongu - Genioglossus protrudes and depresses tongue - Hypoglossus retracts and depresses tongu

Question 35

What are the salivary glands and ducts innervated by?

Answer 35

- innervated by parasympathetic fibers - from facial nerve: submandibular gland, sublingual gland - from glossopharyngeal: parotid gland