Scapular Region

Question 1

Identify the bony landmarks that serve as attachment sites for the scapular muscles.

Answer 1

Medial border, superior border, lateral border, superior angle, inferior angle, lateral angle, subscapular fossae, supraspinous fossae, infraspinous fossae, crest of spine, acromion of spine, spinoglenoid notch of spine, supraglenoid tubercle of glenoid cavity, infraglenoid tubercle of glenoid cavity, coracoid process

Question 2

Name the scapular muscles.

Answer 2

Deltoid, supraspinatus, infraspinatus, teres minor, subscapularis, teres major

Question 3

Name the actions and innervations (including common spinal cord segment) for the deltoid.

Answer 3

C5-C6
Attachments: from the clavicle, acromion and spine of the scapula to the deltoid tuberosity of the humerus
Actions: flexion and medial rotation (anterior), abduction (middle), extension and lateral rotation, horizontal extension of the humerus (posterior)
Innervation: axillary nerve

Question 4

Name the actions and innervations (including common spinal cord segment) for the supraspinatus.

Answer 4

C4-C6
Attachments: from the medial 2/3 of the supraspinous fossa to the superior facet of the greater tubercle of the humerus and to the shoulder joint capsule
Actions: initiates humeral abduction and laterally rotates humerus; stabilizes GH joint (reinforces superior aspect of joint capsule)
Innervation: suprascapular nerve

Question 5

Name the actions and innervations (including common spinal cord segment) for the infraspinatus.

Answer 5

C5-C6
Attachments: from the medial 2/3 of the infraspinous fossa to the middle facet of the greater tubercle of the humerus and to the shoulder joint capsule
Actions: lateral rotation of humerus; stabilize GH joint
Innervation: suprascapular nerve

Question 6

Name the actions and innervations (including common spinal cord segment) for the teres minor.

Answer 6

C5-C6
Attachments: from the upper 2/3 of the dorsal surface of the lateral border of the scapula to the inferior facet of the greater tubercle of the humerus and to the shoulder joint capsule
Actions: medial rotation of the humerus; stabilize GH joint
Innervation: axillary nerve

Question 7

Name the actions and innervations (including common spinal cord segment) for the subscapularis.

Answer 7

C5-C6
Attachments: from the subscapular fossa to the lesser tubercle of the humerus
Actions: medial rotation of humerus; stabilize GH joint
Innervation: upper and lower subscapular nerves

Question 8

Name the actions and innervations (including common spinal cord segment) for the teres major.

Answer 8

C5-C6
Attachments: from the dorsal surface of the inferior angle scapula and lower 1/3 of the lateral border of the scapula to the medial lip of the intertubercular sulcus of the humerus
Actions: humeral adduction, medial rotation, and extension
Innervation: lower subscapular nerve

Question 9

Use a drawing to summarize collateral circulation at the scapula.

Answer 9

See drawing 7

Question 10

Describe the location and contents of the following neruovascular tracts: quadrangular space, medial border of scapula, and scapular notch.

Answer 10

Quadrangular Space: axillary n., posterior circumflex humeral a.
Medial border of scapula: dorsal scapular n., dorsal scapular a.
Scapular notch: suprascapular n., suprascapular a.

Question 11

Describe the following injuries and relate anatomical structures to each: shoulder separation, shoulder dislocation

Answer 11

Shoulder Separation: Grade I (AC ligament sprained with minimal clavicle dislocation), Grade II (AC ligament torn, CC ligament sprained and slight upward movement of clavicle), Grade III (AC and CC ligaments torn and acromion drops down)
Shoulder Dislocation: torn labrum, torn GH ligament, humeral head shifts toward the front of the body

Question 12

Describe the location and contents of the subacromial space.

Answer 12

Location: subacromial bursa, subdeltois bursa, subtendinous of subscapularis bursa
Composition: lined by synovial membrane, filled with synovial fluid

Question 13

Predict what neurovascular structures would be injured based on a bone fracture located at the medial border of the scapula.

Answer 13

Dorsal scapular n. And dorsal scapular a.

Question 14

Describe the location and function of the bursar of the scapular region.

Answer 14

Location: subacromial, subdeltoid, subtendinous of subscapularis
Function: cushion, reduce friction between bone and tendon

Question 15

Identify structures from the Cross Section ID List on the deltoid muscle level photograph on Kenhub

Answer 15

See kenhub