Muscles of the Back

Question 1

Back of the neck is supplied by dorsal rami of the _____ nerves.

Answer 1

cervical

Question 2

Dorsal rami of C1 and C8 carry _____ axons only.

Answer 2

efferent; no sensory function!

Question 3

The first layer of the back consists of:

Answer 3

latissimus dorsi and trapezius

Question 4

The second layer of the back consists of:

Answer 4

splenius muscle, levator scapulae, rhomboid major and minor, serratus posterior superior and serratus posterior inferior muscle

Question 5

Third layer of the back consists of:

Answer 5

erector spinae muscles

Question 6

The fourth layer of the back consists of:

Answer 6

multifidus, rotators, intertransversii, and suboccipital muscles

Question 7

Functionally, only the ____ group is involved in the movement of the vertebral column and maintaining posture.

Answer 7

deep (intrinsic muscles)

Question 8

Deep (intrinsic) muscles are innervated by:

Answer 8

the dorsal rami of the spinal nerves

Question 9

All muscles in the superficial group are supplied by

Answer 9

anterior rami of spinal nerves through brachial plexus except trapezius.

Question 10

Superficial back muscles control ____ ____ movements as well as aid in respiration.

Answer 10

upper limb

Question 11

The origin is the _____ end.

Answer 11

immovable

Question 12

Insertion is the _____ end.

Answer 12

movabale

Question 13

The ____ muscle is a large superficial back muscle that resembles a trapezoid.

Answer 13

trapezius

Question 14

_____ _____ innervates the trapezius muscle.

Answer 14

accessory nerve

Question 15

actions of the trapezius:

Answer 15

• retraction of the scapula
• depression of the scapula
• elevation of the scapula
• superiorly rotates glenoid cavity
• neck extension

Question 16

Actions of the latissimus dorsi:

Answer 16

• medial rotation of shoulder joint
• extension of should joint
• adduction of shoulder joint

Question 17

innervation of the latissimus dorsi

Answer 17

thoracodorsal nerve

Question 18

Actions of the rhomboids

Answer 18

retract, elevate the scapula

Question 19

innervation of the rhomboids

Answer 19

dorsal scapular nerve (C5)

Question 20

Action of levator scapulae

Answer 20

elevation of the scapular only

Question 21

innervation of the levator scapulae

Answer 21

dorsal scapular nerve

Question 22

True muscles of the back and neck: Superficial layer

Answer 22

splenius capitis and splenius cervicis

Question 23

True muscles of the back and neck: intermediate layer

Answer 23

iliocostalis, longissimus, and spinalis

Question 24

True muscles of the back and neck: deep layer

Answer 24

semispinalis, multifidus, rotatores breves and rotatores longi

Question 25

True muscles of the back and neck: deepest layer

Answer 25

interspinales, intertransversarii, levatores costarum

Question 26

innervation of the true muscles of the back and neck

Answer 26

branches of the dorsal rami of the spinal nerves

Question 27

functions of the true muscles of the back and neck

Answer 27

maintain posture; control movement of the vertebral column

Question 28

The most superficial layer of the intrinsic back muscles includes the ____ group of muscles. They extend along the posterior and lateral aspects of the neck and upper part of the thorax.

Answer 28

splenius

Question 29

Action of the splenius group of muscles

Answer 29

bilateral head extension; unilateralL lateral flexion and rotation of the head

Question 30

Erector spinae group muscles are ____ muscles of the back.

Answer 30

true

Question 31

Erector spinae group muscles are supplied by the

Answer 31

dorsal rami of the spinal nerves

Question 32

Which group of muscles are the chief extensor of the vertebral column?

Answer 32

erector spinae

Question 33

Transversospinal group consists of:

Answer 33

semispinalis, mulifidus, rotators

Question 34

action of the transversospinal group

Answer 34

extension and stabilization of the vertebral column

Question 35

Innervation of the transversospinal group

Answer 35

posterior rami of spinal nerves

Question 36

Action of the levator costarum

Answer 36

bilateral: extends thoracic spine
unilateral: bends thoracic spine

Question 37

Triangle of auscultation

Answer 37

A region of the posterior thorax devoid of superficial back muscles, which allows for optimal auscultating lung sounds.

Question 38

Borders of the triangle of auscultation include:

Answer 38

Laterally: medial border of the scapula (border of rhomboid major)
Medially: ascending fibers of the trapezius
Inferiorly: superior border of the latissimus dorsi.

Question 39

Inferior lumbar (petit’s) triangle

Answer 39

a region of the lower back devoid of superficial back muscles, which is mildly susceptible to herniation.

Question 40

Borders of the inferior lumbar triangle include:

Answer 40

laterally: external oblique
medially: latissimus dorsi
inferiorly: iliac crest