L33 Shoulder

Question 1

What are the anatomical regions of the upper extremeties?

Answer 1

Shoulder (pectoral, scapular, deltoid regions)

Arm (brachium)

Forearm (antebrachium)

Hand (palmar/dorsal)

Question 2

What are the bones of the shoulder (pectoral girdle)?

What bone makes up the arm?

Forearm?

Hand?

Answer 2

Clavicle and scapula

Humerus

• ulna (medial)
• radius (lateral)
• carpals (in wrist)
• metacarpals (in palm)
• phalanges (in digits)

Question 3

How is UE Deep Fascia named?

Answer 3

Based on region (e.g. Deltoid fascia)

Deep fascia is continuous with
intramuscular septa that form
fascial compartments

intramuscular septa connects to bone

Question 4

What are the dermatomes of the UE

Answer 4

C5-T1

Question 5

What is the UE cutaneous innervation?

Answer 5

Question 6

What nodes make up the superficial lymphatics?

Answer 6

Cubital Nodes: drain to humeral nodes

Deltopectoral nodes: drain to apical axillary nodes

These are superficial to deep fascia and follow superficial veins

Question 7

What nodes make up the deep llymphatics?

What is the flow pattern of lymph?

Answer 7

Pectoral, Subscapular, Humeral, (central axillary and apical axillary?)

Located deep to deep fascia, follows deep veins

Question 8

What are the bony features of the Scapula?

Answer 8

Scapular Spine: posterior superior ridge

Infraspinous fossa: Posterior body of scapula, inferior to spine

Supraspinous fossa: superior body of scapula

Subscapular fossa: anterior body of scapula

Coracoid process: “hook” projection on lateral edge of superior anterior scapula, helps stabilize stabilize should joint along w/ acromion

Acromion process: lateral end of spine, joins to clavicle, stabilizes shoulder joint

Glenoid cavity: site of articulation w/ head of humerus

Suprascapular notch: On superior anterior edge of scapula, medial coracoid process

Question 9

What is the AC joint?

Answer 9

Acromioclavicular joint: connects clavicle to acromion. -synovial plane joint (rotation)
-partial articular disc process.
Stabilized by:
coracoacromial lig.,
acromioclavicular lig.,
coracoclavicular ligaments: trapezoid (lateral) and conoid (medial)

Question 10

What is the SC joint?

Answer 10

• *Sternoclavicular (SC) joint**: connects clavicle to sternum
• synovial ball & socket
• articular disc
• strong

Stabilized by:

• *Interclavicular lig** (over jugular notch)
• *Ant/Post sternoclavicular** ligs
• *Costoclavicular** lig

Only joint between UE and body

Question 11

How is the humerus joined to the scapula?

What are the joint’s components?

Answer 11

• *Glenohumeral (shoulder) joint**: head of humerus to glenoid cavity
• synovial ball in socket
• most freedom of any joint

Components (from exterior to interior):
Rotator Cuff tendons, Coracohumeral lig.
Glenohumeral ligs.
Glenoid Labrum: fibrocartilage
-extends socket

Question 12

Shoulder joint summary of movements

SC

AC

Glenohumeral

Answer 12

Sternoclavicular (SC) joint
-circumduction

Acromioclavicular (AC) joint
-rotation

Glenohumeral (shoulder) joint
-flexion/extension, abduction/adduction,
medial/lateral rotation, circumduction

Question 13

Extrinsic shoulder muscles: attachments
outside the UE, but act on UE; “axioappendicular”

Answer 13

trapezius: elevate, depress, retract
scapula

latissimus dorsi: extend, adduct, medially
rotate humerus

levator scapulae: elevate scapula, inferiorly
rotate glenoid cavity

rhomboids: retract scapula, inferiorly
rotate glenoid cavity

Pectoralis major: adduct, medially rotate humerus

Pectoralis minor: stabilize scapula

Serratus anterior: protract scapula

Question 14

trapezius

Answer 14

PA: sup. nuchal line, EOP,
nuchal lig. Sp C7-T12
DA: clavicle, acromion process,
scapular spine
Act: elevate, depress, retract
scapula
Inn: spinal accessory n (CN XI)

Question 15

latissimus dorsi

Answer 15

PA: sp T7-T12,
thoracolumbar fascia,
iliac crest
DA: intertubercular sulcus
Act: extend, adduct, medially
rotate humerus
Inn: thoracodorsal n

Question 16

levator scapulae

Answer 16

PA: tp C1-C4
DA: medial border of scapula
Act: elevate scapula, inferiorly
rotate glenoid cavity
Inn: dorsal scapular n

Question 17

rhomboid major & minor

Answer 17

PA: sp T2-T5, nuchal lig. (maj)
sp C7 & T1 (min)
DA: medial border of scapula
Act: retract scapula, inferiorly
rotate glenoid cavity
Inn: dorsal scapular n

Question 18

pectoralis major

Answer 18

PA: clavicle, sternum, costal cartilage 1-6
DA: intertubercular sulcus
Act: adduct, medially rotate humerus
Inn: medial & lateral pectoral nn

Question 19

pectoralis minor

Answer 19

PA: ribs 3-5
DA: coracoid process
Act: stabilize scapula
Inn: medial pectoral n

Question 20

serratus anterior

Answer 20

PA: ribs 1-8
DA: medial border of scapula
Act: protract scapula
Inn: long thoracic n

Question 21

Intrinsic shoulder muscles:
all attachments are within the
UE, “scapulohumeral”

Answer 21

Deltoid: abduct, medially rotate humerus

Supraspinatus: initiates abduction of humerus

Infraspinatus: laterally rotates humerus

Teres minor: adducts and laterally rotates humerus

Teres major: adducts and medially rotates humerus

Subscapularis: medially rotates & adducts humerus

Question 22

Deltoid

What muscle aids deltoid action?

What is the deltoid a common site for?

Answer 22

PA: clavicle, acromion, scapular spine
DA: deltoid tuberosity
Act: abduct, medially rotate humerus
Inn: axillary n

Deltoid is aided by supraspinatus for first 15°
of abduction, remainder is primarily deltoid
and upward rotation of the scapula

Intramuscular injections, 2-3 finger breadths below
acromion process

Question 23

supraspinatus

Answer 23

PA: supraspinous fossa
DA: greater tubercle of humerus (superior facet)
Act: initiates abduction of humerus
Inn: suprascapular n

Question 24

infraspinatus

Answer 24

PA: infraspinous fossa
DA: greater tubercle (inferior facet)
Act: laterally rotates humerus
Inn: suprascapular n

Question 25

teres minor

Answer 25

PA: lateral border of scapula DA: greater tubercle (inferior facet) Act: adducts and laterally rotates humerus Inn: lower subscapular n

Question 26

teres major

Answer 26

PA: inferior angle of scapula DA: intertubercular sulcus Act: adducts and medially rotates humerus Inn: long thoracic n

Question 27

subscapularis

Answer 27

PA: subscapular fossa DA: lesser tubercle Act: medially rotates & adducts humerus Inn: upper & lower subscapular nn

Question 28

Rotator Cuff: function and components

Answer 28

Increases stability of the shoulder (glenohumeral) joint Rotator cuff muscles (**SITS**): supraspinatus infraspinatus teres minor subscapularis

Question 29

Degenerative tendonitis of the rotator cuff: What might lead to a tear? Where is injury most common? How is this injury tested?

Answer 29

Repetitive use → inflammation → impingement on coraco-acromial arch Sudden strain on degenerating cuff may lead to rotator cuff tearing **Injury to supraspinatus most common** Test: cannot initiate abduction; if fully abducted, arm falls in an uncontrolled manner during slow adduction

Question 30

What are the major arteries of the shoulder (not including axiallary branches)?

Answer 30

**Subclavian a**. gives rise to: **Thyrocervical trunk** which gives rise to: -inferior thyroid a. -transverse cervical a. (w/ spinal access. n.) -suprascapular a. (w/ suprascapular n.) **Dorsal scapular a.** (w/ dorsal scapular n.) **Axillary a.**

Question 31

“Army over Navy” What artery, nerve, and ligament is involved and how are they oriented?

Answer 31

* *Suprascapular a. courses superior** to the superior transverse scapular ligament * *Suprascapular n. courses inferior** to the superior transverse scapular ligament superior transverse scapular ligament covers suprascapular notch

Question 32

Axillary a. What are it's boundaries and branches?

Answer 32

* *First part**: boundary = 1st rib to (pec minor?) * *single branch: superior thoracic a** * *Second part:** (beneath pectoralis minor?) * *Two branches:** - **thoracoacromial a.**: - pectoral branch - clavicular branch - acromial branch - deltoid branch - **lateral thoracic a.** * *Third Part:** Superior boundary = teres minor, inferior = teres major, medial = long head of tricep m, lateral = surgical head of humerus * *Three Branches:** - subscapular a. - anterior humeral circumflex a. - posterior humeral circumflex a.

Question 33

**Quadrangular (quadrilateral) space** Contains? Boundaries? Trauma or compression?

Answer 33

**Contains:** Axillary n. Posterior humeral circumflex artery **Formed by:** Teres minor Long head of triceps brachii Teres major Surgical neck of humerus * *Trauma or compression:** - quadrangular space syndrome - shoulder pain & parasthesia

Question 34

Shoulder Veins

Answer 34

Transverse cervical & Suprascapular veins → External jugular v. → Subclavian v.