Lecture 10- Extrinsic Back Muscles

Question 0

Superficial extrinsic

•Produce & control …….. …… …….

Answer 0

upper limb movements

Question 1

Superficial extrinsic
•Posterior axio-appendicular muscles => connect …… skeleton with ……. …….. skeleton (pectoral girdle and humerus).

Answer 1

axial

superior appendicular

Question 2

Superficial extrinsic

•Mostly innervated by ……. …….. of cervical spinal nerves (despite being dorsal muscles!).

Answer 2

anterior rami

Question 3

Superficial extrinsic muscles

•Include:

Answer 3

• Trapezius
• Latissimus dorsi
• Levator scapulae
• Rhomboid major
• Rhomboid minor

Question 4

Trapezius

Proximal attachment

Answer 4

Meidal third of superior nuchal line; external occiptal protuberance; nuchal ligament; spinous processes of C7-T12 vertebrae

Question 5

Trapezius

Distal attachment

Answer 5

Lateral third of clavicle; acromion and spine of scapula

Question 6

Trapezius

Innervation

Answer 6

Motor: Spinal accessory nerve (CN XI)
Sensory: C3 & C4 spinal nerves

Question 7

Trapezius

Main actions

Answer 7

Descending part elevates; ascending part depresses; middle part (or all parts together) retracts scapula;
Descending and ascending parts together rotate glenoid cavity superiorly.

Question 8

Latissimus dorsi

Proximal attachment

Answer 8

Spinous processes of T7 to T12, thoracolumbar fascia, iliac crest, ribs 10-12

Question 9

Latissimus dorsi

Distal attachment

Answer 9

Floor of intertubular sulcus of humerus

Question 10

Latissimus Dorsi

Innervation

Answer 10

Thoracodorsal nerve
(C6, C7, C8)

Question 11

Latissimus Dorsi

Main Action

Answer 11

Extends, adducts and medially rotates humerus

Raises body toward arms during climbing

Question 12

Levator scapulae

Proximal attachment

Answer 12

Posterior tubercles of transverse processes of C1-C4 vertebrae

Question 13

Levator scapulae

Distal attachment

Answer 13

Medial border of scapula superior to root of scapular spine

Question 14

Levator Scapula

Innervation

Answer 14

Dorsal scapular (C5) and cervical (C3, C4) nerves

Question 15

Levator scapulae

Main actions

Answer 15

Elevates scapula

Tilts glenoid cavity inferiorly (by rotating scapula)

Question 16

Rhomboid major

Proximal attachment

Answer 16

Spinous processes

of T2-T5 vertebrae

Question 17

Rhomboid Major

Distal attachment

Answer 17

Medial border of scapula from level of spine to inferior angle

Question 18

Rhomboid Major

Innervation

Answer 18

Dorsal scapular nerve

C4, C5

Question 19

Rhomboid Major

Main actions

Answer 19

Retracts scapula and rotate it to depress glenoid cavity

Fix scapula to thoracic wall

Question 20

Rhomboids minor

Proximal attachment

Answer 20

Nuchal ligament

Spinous processes of C7 & T1 vertebrae

Question 21

Rhomboid Major

Distal attachment

Answer 21

Smooth triangular area at medial end of scapular spine

Question 22

Rhomboid Minor

Innervation

Answer 22

Dorsal scapular nerve

C4, C5

Question 23

Rhomboid Minor

Main actions

Answer 23

Retracts scapula and rotate it to depress glenoid cavity

Fix scapula to thoracic wall

Question 24

Rhomboid Minor | Intermediate extrinsic

Answer 24

* Serratus posterior superior | * Serratus posterior inferior

Question 25

Intermediate extrinsic No what? Innervation?

Answer 25

No respiratory function | Innervated by intercostal nerves.

Question 26

Serratus posterior superior | Superior attachment

Answer 26

Nuchal ligament, spinous processes of C7 to T3

Question 27

Serratus posterior superior | Inferior attachment

Answer 27

Superior borders of 2nd to 4th ribs

Question 28

Serratus posterior superior | Innervation

Answer 28

2nd to 5th intercostal nerves

Question 29

Serratus posterior superior | Main action

Answer 29

Proprioception | (Elevates ribs)

Question 30

Serratus posterior inferior | Superior attachment

Answer 30

Spinous processes | of T11 to L2

Question 31

Serratus posterior inferior | Inferior attachment

Answer 31

Inferior borders of 8th to 12th ribs near their angles

Question 32

Serratus posterior inferior | Innervation

Answer 32

Anterior rami to T9 to T12 thoracic spinal nerves

Question 33

Serratus posterior inferior | Main Action

Answer 33

Proprioception | (Depress ribs)

Question 34

The thoracodorsal nerve innervates which extrinsic back muscle?

Answer 34

Latissimus Dorsi

Question 35

Which nerve provides motor innervation to trapezius?

Answer 35

Motor: Spinal accessory nerve (CN XI)

Question 36

What is the main action of levator scapulae?

Answer 36

Elevates the scapula

Question 37

Which nerve spinal cord segments contribute to the dorsal scapular nerve?

Answer 37

C4, C5

Question 38

What is the main action of the serratus posterior muscles?

Answer 38

Proprioception