scapular region LOs

Question 1

deltoid

Answer 1

• BL: clavicle/acromion/spine of scapule > deltoid tuberosity of humerus
• SC segment: C5-6
• action: flexion/medial rotation (anterior), abduction (middle), extension/lateral rotation/horizontal extension (posterior) of humerus
• innervation: axillary nerve

Question 2

supraspinatus

Answer 2

• BL: medial 2/3 of supraspinous fossa > superior facet of greater tubercle of humerus/shoulder joint capsule
• SC segment: C4-6
• action: initiates humeral abduction, laterally rotates humerus, stabilizes GH joint
• innervation: suprascapular nerve

Question 3

infraspinatus

Answer 3

• BL: medial 2/3 of infraspinous fossa > middle facet of greater tubercle of humerus, shoulder joint capsule
• SC segment: C5-6
• action: lateral rotation of humerus, stabilize GH joint
• innervation: suprascapular nerve

Question 4

teres minor

Answer 4

• BL: upper 2/3 of dorsal lateral border of scapula > inferior facet of greater tubercle of humerus, shoulder joint capsule
• SC segment: C5-6
• action: lateral rotation of humerus, stabilizes GH joint
• innervation: axillary nerve

Question 5

subscapularis

Answer 5

• BL: subscapular fossa > lesser tubercle of humerus
• SC segment: C5-6
• action: medial rotation, stabilizes GH joint
• innervation: upper and lower subscapular nerves

Question 6

teres major

Answer 6

• BL: dorsal surface of inferior angle of scapula/lower 1/3 of lateral border of scapulae > medial of the intertubercular sulcus of humerus
• SC segment: C5-6
• action: humeral adduction, medial rotation, extension
• innervation: lower subscapular

Question 7

collateral circulation of scapula

Answer 7

MEDIALLY

• subclavian artery > dorsal scapular artery

LATERALLY

• subclavian artery > thyrocervical > suprascapular
• subclavian > axillary > subscapular > thoracodorsal/circumflex scapular

Question 8

quadrangular space

Answer 8

• border
  
  • lateral to long head of triceps brachii
  • inferior to teres minor
  • superior to teres maojor
  • medial to humerus
• contains
  
  • axillary nerve
  • posterior circumflex humeral artery

Question 9

medial border of scapula neurovasculature

Answer 9

• border
  
  • medial to scapula
• contents
  
  • dorsal scapular nerve
  • dorsal scapular artery

Question 10

scapular notch neurovasculature

Answer 10

• border
  
  • superficial to scapula
  • near transverse scapular ligament
• contains
  
  • suprascapular nerve (deep to/below ligament)
  • suprascapular artery (superficial)

Question 11

shoulder separation

Answer 11

• due to FOOSH: fall on an outstretched hand
• injuries to acromioclavicular ligament and coracoclavicular ligament (torn in severe cases)
• clavicle moves over the acromion, acromion free to move inferiorly and damage GH joint

Question 12

shoulder dislocation

Answer 12

• GH most frequently dislocated joint in body
  
  • inferior capsule not reinforced by rotator cuff/ligaments
  • creates vulnerability in abducted position
• anterior dislocation is 95%
  
  • risks damaging axillary contents when head of humerus descends

Question 13

subacromial space

Answer 13

• space above glenohumeral joint and below acromion
• contains bicep tendon, rotator cuff, bursa
• subacromial bursa: between acromion and suprasinatus tendon

Question 14

neurovascular structures that would be injured based on bone fracture at medial border of scapula

Answer 14

dorsal scapular nerve and artery

Question 15

location/function of bursae in scapular region

Answer 15

• scapular bursae with synovial membranes/fluid reduce friction between bones and tendons
• subacromial bursa: between acromion and supraspinatus tendon
• subdeltoid bursa: between greater tubercle of humerus and deltoid tendon
• subtendinous bursa of subscapularis: between coracoid process and subscapularis tendon

Question 16

humerus (cross section)

Answer 16

Question 17

scapula (cross section)

Answer 17

Question 18

deltoid (cross section)

Answer 18

Question 19

infraspinatus (cross section)

Answer 19

Question 20

subscapularis (cross section)

Answer 20

Question 21

trapezius (cross section)

Answer 21