Practical 1 Muscle Actions and Innervations

Question 1

What is the innervation of trapezius?

Answer 1

spinal accessory nerve, C1-C5 cord levels

Question 2

What is the innervation of latissimus dorsi?

Answer 2

thoracodorsal nerve, ventral rami C6-C8

Question 3

What is the innervation of levator scapulae?

Answer 3

dorsal scapular nerve, ventral ramus C5 plus ventral rami C3, C4

Question 4

What is the innervation of rhomboid major?

Answer 4

dorsal scapular nerve, ventral ramus C5 plus ventral ramus C4

Question 5

What is the innervation of rhomboid minor?

Answer 5

dorsal scapular nerve, ventral ramus C5 plus ventral ramus C4

Question 6

What is the innervation and action of splenius capitis?

Answer 6

I: dorsal rami C3-C5
A: laterally flex head and rotate face to side; bilaterally extend head

Question 7

What is the innervation and action of splenius cervicis?

Answer 7

I: dorsal rami C5-C7
A: laterally flex and rotate neck; bilaterally extend neck

Question 8

What is the innervation and action of iliocostalis lumborum?

Answer 8

I: dorsal rami lower T, all L
A: extension, lateral flexion, rotation of L spine; lateral movement of pelvis

Question 9

What is the innervation and action of iliocostalis thoracis?

Answer 9

I: dorsal rami T1-T6
A: extension, lateral flexion T spine

Question 10

What is the innervation and action of iliocostalis cervicis?

Answer 10

I: dorsal rami T1, T2; rarely C8
A: extension, lateral flexion, rotation lower C spine

Question 11

What is the innervation and action of longissimus thoracis?

Answer 11

I: dorsal rami T and L nerves
A: lateral flexion T spine and ribs (L spine inadvertently); bilaterally act in extension of T and L spine, hold T and L spine erect (increases L lordosis); lateral movement of pelvis

Question 12

What is the innervation and action of longissimus cervicis?

Answer 12

I: dorsal rami C4-C8; T1-T2
A: lateral flexion of neck; bilaterally extend neck

Question 13

What is the innervation and action of longissimus capitis?

Answer 13

I: dorsal rami C1-C3, sometimes C4
A: rotate and laterally flex head; bilaterally extend head

Question 14

What is the innervation and action of spinalis thoracis?

Answer 14

I: dorsal rami T and upper L
A: extend T spine

Question 15

What is the innervation and action of spinalis cervicis?

Answer 15

I: dorsal rami C
A: lateral flexion and rotation of C spine; bilaterally extend neck

Question 16

What is the innervation and action of spinalis capitis?

Answer 16

I: dorsal rami lower C, upper T
A: lateral flexion and rotation of head; bilaterally extend head

Question 17

What is the innervation and action of semispinalis thoracis?

Answer 17

I: dorsal rami T1-T6
A: extension, rotation, and lateral flexion of upper T and lower C spine; bilaterally extend T spine

Question 18

What is the innervation and action of semispinalis cervicis?

Answer 18

I: dorsal rami C6-C8
A: extension, rotation, and lateral flexion of C spine; bilaterally extend neck

Question 19

What is the innervation and action of semispinalis capitis?

Answer 19

I: dorsal rami C1-C6
A: turns face to side; bilaterally extends head (neck inadvertently)

Question 20

What is the innervation of multifidus?

Answer 20

dorsal rami C3-C8, T1-T12, L1-L5, sometimes S1

Question 21

What is the innervation and action of rectus capitis posterior major?

Answer 21

I: suboccipital nerve, dorsal ramus C1
A: turns face to side; bilaterally extends head

Question 22

What is the innervation and action of rectus capitis posterior minor?

Answer 22

I: suboccipital nerve, dorsal ramus C1
A: extends head

Question 23

What is the innervation and action of obliquus capitis superior?

Answer 23

I: suboccipital nerve, dorsal ramus C1
A: lateral flexion of head; bilaterally extends head

Question 24

What is the innervation and action of obliquus capitis inferior?

Answer 24

I: suboccipital nerve, dorsal ramus C1
A: turns face to side

Question 25

What is the innervation and action of quadratus lumborum?

Answer 25

I: ventral rami T12, L1-L3 or L4
A: steadies origin of diaphragm; when pelvis is fixed, it will laterally flex the L spine; bilaterally extends the L spine; stabilizes and depresses the 12th rib

Question 26

What is the innervation and action of serratus posterior superior?

Answer 26

I: intercostal nerves, ventral rami T2-T5
A: elevate upper 5 ribs in inspiration

Question 27

What is the innervation and action of serratus posterior inferior?

Answer 27

I: intercostal nerves, ventral rami T9-T11; subcostal nerve, ventral ramus T12
A: draws lower 4 ribs down and back; forced inspiration

Question 28

What is the innervation and action of longus colli?

Answer 28

I: ventral rami C2-C6, sometimes C7
A: flexion and extension of neck; rotation to the contralateral side

Question 29

What is the innervation and action of longus capitis?

Answer 29

I: ventral rami C1-C3
A: flex the head

Question 30

What is the innervation and action of rectus capitis anterior?

Answer 30

I: ventral rami C1, C2
A: flex the head

Question 31

What is the innervation and action of rectus capitis lateralis?

Answer 31

I: ventral rami C1, C2
A: laterally flex the head to the ipsilateral side

Question 32

What is the innervation of anterior scalene?

Answer 32

ventral rami C2-C6

Question 33

What is the innervation of middle scalene?

Answer 33

ventral rami C3-C8

Question 34

What is the innervation posterior scalene?

Answer 34

ventral rami C6-C8