Muscles of mastication

Question 1

What are the muscles used for closing the mouth?

Answer 1

Temporalis, masseter, mylohyoides and pterygoide

Question 2

What are the muscles for opening the mouth?

Answer 2

Digastricus muscle

Question 3

What is the innervation for the muscles of opening the mouth?

Answer 3

Mandibular nerve

Question 4

What is the innervation of the muscle that helps open the mouth?

Answer 4

Rostral part - mandibular nerve

Caudal part - facial nerve

Question 5

What is the action of the temporalis muscle?

Answer 5

O: Lateral surface of skull and I: coronoid process of the mandible
Therefore contraction will raise the mandible
Bigger in carnivore for shearing

Question 6

What is the action of the masseter muscle?

Answer 6

Masseter muscle sits lateral to the mandibe
O: maxillary region and zygomatic arch and I: caudal part of the mandible
Which when contracted will raise the mandible and draw it to the side of action (side to side)
Bigger in herbivores

Question 7

What is the action of the pterygoide muscle?

Answer 7

Runs medial to the mandible (wont see on superficial prosection)
O: Pterygopalatine bone
I: Mandible
It raises the mandible and draws it inwards

Question 8

What is the action of digastricus muscle?

Answer 8

Originates: caudal to temporal mandibular join
I: ventral margin of mandible
Opens the mandible (assisted by gravity)