Exam 3: Shoulder

Question 1

Extrinsic Muscles

Answer 1

• thoracoappendicular
• has attachment to thoracic wall
• ant (4): pec major, minor, subclavius, serratus ant.
• post (4):
  
  • superficial: trapezius, lattisimus dorsi
  • deep: levator scapulae & rhomboids

Question 2

Intrinsic Muscles

Answer 2

• scapulohumeral
• only attach to shoulder bones
• deltoid, trees major, 4 rotator cuff muscles

Question 3

Pec Major

Answer 3

ORIGIN: clavicular head & sternocostal head
INSERTION: lat. lip of inter tubercular groove of hum.
FUNCTION: adduct & med. rotate hum., flex clavicle
INNERVATION: med. & lat. pectoral n.

Question 4

Pec Minor

Answer 4

*lies under/covered by pec major
ORIGIN: coracoid process
INSERTION: ribs 3,4,5
FUNCTION: fix scapula to thoracic wall, stretch arm forward, lift ribs when pec girdle is fixed/elevated for inspiration
INNERVATION: med. pectoral n.

Question 5

Subclavius

Answer 5

*some protection to subclavian a. & other vessels
ORIGIN: 1st rib & its costal cartilage
INSERTION: mid. 3rd of clavicle at inf. surface
FUNCTION: anchors & depresses clavicle

Question 6

Serratus Anterior

Answer 6

ORIGIN: external lateral surface rubs 1-8
INSERTION: medial border of scapula
FUNCTION: protracts scapula (punch & reach), rotates inf angle of soap. so gleaned is raised (combing hair), holds cap against thoracic wall
INNERVATION: long thoracic n.

Question 7

Shoulder Paralysis

Answer 7

• cause: injury to long thoracic n. or any injury above nerves spinal level
• appearance: winged
  
  • med border & inf angle of scapula is pulled away from posterior thoracic wall, particularly when arm is raised or pushing ant. against object
• cannot abduct above horizontal

Question 8

Trapezius

Answer 8

ORIGIN: sup. nuchal line, C7-T12
INSERTION: lat. clavicle, acromion, spine of scapula
FUNCTION:
-sup. fibers- elevate scap
-mid fibers- retract cap
-inf fibers- depress scap & lower shoulder
-cooperation of sup. & inf fibers rotate scap
INNERVATION: spinal accessory n.

*to test- shrug against resistance

Question 9

Latissimus Dorsi

Answer 9

ORIGIN: T7, thoracolumbar fascia, iliac crest
INSERTION: floor of inter tubercular groove of humerus
FUNCTION: extends, adducts & medially rotates hum., bring body towards arm (climbing)
INNERVATION: thoracodorsal n.

Question 10

Injury to Thoracodorsal Nerve

Answer 10

• can be injured during surgery
• unable to use axillary crutch b/c no counter force for should when it is pushed up by crutch
• cannot climb

Question 11

Levator Scapulae

Answer 11

*sup. 3rd lies deep to sternocleidomastoid
*inf 3rd lies deep to trap.
ORIGIN: transverse process of C1-4
INSERTION: med. border (superior angle) of soap
FUNCTION: elevate scapula
INNERVATION: dorsal scapular n.

Question 12

Rhomboids

Answer 12

*lies deep to trap
ORIGIN: C7-T5
INSERTION: med. border of scap
FUNCTION: retract scapula
INNERVATION: dorsal scapular n

Question 13

Deltoid

Answer 13

ORIGIN: spine of scapula, accordion, clavicle
INSERTION: deltoid tuberosity (shaft of humerus)
FUNCTION: abduction, flexion, extension, stabilizes shoulder joint by holding head of hum. in gleaned cavity during movement
INNERVATION: axillary n.

*when examining- start after abducting arm 15 degrees

Question 14

Injury of Axillary Nerve

Answer 14

• causes- shoulder joint dislocation, hum. surgical neck fracture & intramuscular injection of medication
• appearance- loss of sensation on the lateral side of poximal arm skin. muscle atrophy- loss of shoulder contour

Question 15

Teres Major

Answer 15

ORIGIN: inferior angle of scapula
INSERTION: med. lip of interlobular groove
FUNCTION: stabilizes hum head in socket & counteracts deltoid during abduction
-adduction & med. rotate of humerus
INNERVATION:

Question 16

Triangular Space

Answer 16

exits circumflex scapular a.

Question 17

Quadrangular Space

Answer 17

exits post. circumflex hum. a. & axillary n.

Question 18

Rotator Cuff (SITS)

Answer 18

Supraspinatus-insert greater tubercle
Infraspinatus- insert greater tubercle
Teres Minor- insert greater tubercle
Subscapularis- insert lesser tubercle
FUNCTION:
-supraspinatus: abduct
-subscapularis & teres minor- adduct
-subscapularis, teres minor- medial rotate
-infraspinatus & teres minor- laterally rotate

Question 19

Rotator Cuff Injuries

Answer 19

• cause- avoiding crashing into object, throwing ball hard, shoulder dislocation
• result- pain in anterosuperior part of shoulder, shoulder joint dislocation
• testing- lower fully abducted arm slow & smooth, when reach 90 degrees- arm suddenly drops (supraspinatus injury)

Question 20

Subacromial Bursistis & Calcific Supraspinatus Tendinitis

Answer 20

• location- between tendon of supraspinatus & acromion, coracoacromial ligament & deltoid
• result- pain during abduction –> Painful Arc Syndrome