Extrinsic Muscles of the Shoudler Flashcards Preview

ESA 2- Musculoskeletal System > Extrinsic Muscles of the Shoudler > Flashcards

Flashcards in Extrinsic Muscles of the Shoudler Deck (36):
1

What are the muscles of the shoulder associated with?

Movements of the upper limb

2

What do the muscles of the shoulder produce?

The characteristic shape of the shoulder

3

What can the muscles of the shoulder be divided into?

Extrinsic 
Intrinsic

4

What are the extrinsic muscles of the shoulder?

Those that originate from the torso, and attach to the bones of the shoulder (clavicle, scapula or humerus)

5

What are the intrinsic muscles of the shoulder?

Those that originate form the scapula and/or clavicle, and attach to the humerus

6

Where are the extrinsic shoulder muscles located?

In the back

7

What are the extrinsic shoulder muscles organised into?

A superficial and deep layer

8

What are the superficial extrinsic shoulder muscles?

Trapezius 
Latissimus dorsi

9

What is the most superficial of all the back muscles?

The trapezius

10

What shape is the trapezius?

Broad, flat, triangular

11

What do the muscles on each side of the trapezius form?

A trapezoid shape

12

What is the innervation of the trapezius?

Spinal accessory nerve (CN XI) 
C3, C4 spinal fibres

13

What is the function of the spinal accessory nerve on the trapezius?

Motor functions

14

What is the function of the C3 and C4 spinal nerves on the trapezius?

Pain reception and proprioception

15

What is the arterial supply of the trapezius?

Transverse cervical artery

16

What is the action of the trapezius?

Descending part elevates and rotates during abduction of arm
Ascending part depresses 
Middle part (or all parts together) retracts scapula 
Descending and ascending parts together rotate glenoid cavity superiorly

17

What is the most common cause of accessory nerve damage?

Iatrogenic

18

What is meant by iatrogenic?

Due to a medical procedure

19

What medical procedure in particular can cause trauma to the accessory nerve?

Operations such as cervical lymph node biopsy or cannulation of the internal jugular vein

20

How is the accessory nerve tested?

Trapezius function can be assessed

21

How can trapezius function be assessed?

By asking the patient to shrug his/her shoulders

22

What are the other clinical features of accessory nerve damage?

Muscle wasting
Partial paralysis of sternocleidomastoid 
Asymmetrical neckline

23

What happens to the fibres of the latissimus dorsi?

They converge into a tendon

24

What is the innervation of the latissimus dorsi?

Thoracodorsal nerve (C6-8)

25

What is the arterial supply of the latissimus dorsi?

Thoracodorsal artery

26

What is the action of the latissimus dorsi?

Extends, adducts, and medially rotates the humerus 
Raises body towards arm during climbing

27

What are the deep extrinsic muscles of the shoulder?

The levator scapulae 
Rhomboid minor 
Rhomboid major

28

Where are the deep extrinsic muscles of the shoulder?

In the upper back, under the trapezius

29

What shape is the levator scapulae?

Small, strap-like

30

What is the innervation of the levator scapulae?

Dorsal scapular nerve (C4, C5)
Cervical nerve (C3, C4)

31

What is the arterial supply of the levator scapulae?

Transverse cervical artery and ascending cervical artery

32

What is the action of the levator scapulae?

Elevates scapula and rotates its glenoid cavity inferiorly by rotating scapula

33

Where is the rhomboid minor situated relative to the rhomboid major?

Superiorly

34

What is the innervation of the rhomboid muscles?

Dorsal scapular nerve (C4, C5)

35

What is the action of the rhomboid muscles?

Retract scapula and rotate its glenoid cavity inferiorly
Fix scapula to thoracic wall

36

Draw a diagram illustrating the extrinsic muscle of the shoulder

Answer…