5.1 Anatomy of the Muscular System: Intro Part 3

Question 1

What is the action of the masseter?

Answer 1

jaw closure

Question 2

What is the innervation of the masseter?

Answer 2

CN V mandibular branch (trigeminal nerve)

Question 3

What is the action of the temporalis?

Answer 3

elevates mandible, closes jaw

Question 4

What is the innervation of the temporalis?

Answer 4

CN V mandibular branch (trigeminal nerve)

Question 5

What is the head also known as?

Answer 5

occiput

Question 6

What is side bending of the neck also known as?

Answer 6

lateral flexion

Question 7

What is neck flexion?

Answer 7

action of moving the chin towards the sternum

Question 8

What does it mean for muscles to be bilateral?

Answer 8

when several muscles have differing actions acting together on both sides

Question 9

What does it mean for muscles to be unilateral?

Answer 9

several muscles that have differing actions acting on one side

Question 10

What are the important muscles of the head and neck?

Answer 10

semispinalis capitis
sternocleidomastoid
splenius capitis
longissimus cervicis
longissimus thoracis
thyrohoid
scalenes (anterior, posterior, middle)

Question 11

What is the origin and insertion of the semispinalis capitis?

Answer 11

origin = articular process of inferior cervical and transverse process of superior thoracic vertebra
insertion = occipital bone

Question 12

What is the action of the semispinalis capitis?

Answer 12

bilateral extend head
unilateral laterally flexes neck to same side

Question 13

What is the innervation of the semispinalis capitis?

Answer 13

spinal nerves

Question 14

What is the origin and insertion of the sternocleidomastoid?

Answer 14

origin = sternal end of clavicle and manubrium
insertion = mastoid region of skull

Question 15

What is the action of the sternocleidomastoid?

Answer 15

bilateral = neck flexion
unilateral = turns face to opposite side

Question 16

What is the innervation of the sternocleidomastoid?

Answer 16

CN XI (accessory nerve)

Question 17

What is the origin and insertion of the splenius capitis?

Answer 17

origin = spinous process/ligaments of inferior cervical vertebra
insertion = mastoid process, occipital bone of the skull

Question 18

What is the action of the splenius capitis?

Answer 18

bilateral extend head
unilateral laterally flexes neck to same side

Question 19

What is the innervation of the splenius capitis?

Answer 19

cervical spinal nerves

Question 20

What is the origin and insertion of the longissimus cervicis?

Answer 20

origin = transverse process of superior thoracic vertebra
insertion = transverse process of middle and superior cervical vertebra