2.2.3. Posterior Shoulder

Question 1

label the parts of the scapula

Answer 1

1. supraspinous process
2. infraspinous fossa
3. spine
4. scapular notch (suprascapular notch
5. acromion
6. infraglenoid tubercle - origin of of triceps brachii

Question 2

label the parts of the scapula

Answer 2

1. glenoid cavity with the upper portion of the supraglenoid tubercle (bicep brachii attachment) and the lower portion of the (3.) infraglenoid tubercle (tricep brachii attachment)
2. neck
3. coracoid process

Answer 3

1- head

2- lesser tubercle & its crest (the ridge that is the continuation of the tubercle)

3- greater tubercle & its crest (the ridge that is the continuation of the tubercle)

4- intertubercular sulcus (bicipital groove – where the tendon of the long head

of the biceps runs)

5- anatomic neck (along the capsule of the glenohumeral joint) (GA p 526A)

6- surgical neck (runs across the metaphysis - space between ball portion (epiphysis) and the shaft (diaphysis) that is considered to be part of the growth plate)

Answer 4

1- radial groove (spiral groove for the radial nerve & deep brachial artery)

2- head of humerus

Question 5

What is the significance of the deltoid tuberosity?

Answer 5

Where the deltoid attaches

Answer 6

1. deltoid
2. supraspinatus
3. infraspinatus
4. teres major
5. teres minor
6. long head of triceps brachii
7. lateral head of triceps brachii

Question 7

Where does the deltoid attach?

Answer 7

Origin: lateral third of clavical

         lateral acromion

         and inferior edge of spine of scapula

Insertion: the deltoid protuberance of humerus

Question 8

Where does the supraspinatus attach?

Answer 8

supraspinatus - attaches to the supraspinous fossa of the scapula and the greater tubercle of the humerus

Question 9

Where does the infraspinatus attach?

Answer 9

infraspinatus - attaches to the infraspinous fossa of the scapula and the greater tubercle of the humerus;

Question 10

Teres Major Attachments?

Answer 10

Goes from the posterior aspect of the inferior angle of the scapula and inserts at the intertubercular sulcus of the humerus

Question 11

Action of the teres minor?

Answer 11

laterally rotates the arm and stabilizes the humerus

Question 12

Question 13

What are the four SITS muscles?

Answer 13

Supraspinatus

Infraspinatus

Teres Minor

Subscapularis

Question 14

What do the SITS muscles do?

Answer 14

these four miscles form the musculotendinous rotator cuff; they assist the deltoid in the first 15 degrees of arm abduction

Question 15

In what posture do patients usually sustain rotator cuff injuries

Answer 15

the most common injuries arise from use above the “horizontal” level (i.e. swimming, throwing, racquet sports, weightlifting)

Question 16

How does one test a patient for “degenerative tendonitis of the rotator cuff”

Answer 16

ask the patient to lower the fully abducted limb slowly and smoothly; from approximately 90 degrees abduction, the limb will suddenly drop if there is a rotator cuff issue.

Question 17

Describe the parts of the axillary artery

Answer 17

Part 1 - located between the 1st rib and pectoralis major; enclosed in axillary artery sheath with one branch (superior thoracic artery)

Part 2 - posterior to the pectoralis major, has 2 branches (thoracoacromial and lateral thoracic arteries)

Part 3 - extends from the lateral border of the pectoralis minor to the inferior border of the teres major; has 3 branches (largest - subscapular artery, anterior circumflex humeral and posterior circumflex humeral arteries)

Question 18

What is the triangular space?

Answer 18

the triangle bounded by the teres major, teres minor, & the long head of the triceps

Question 19

What is the triangular interval?

Answer 19

between the long & lateral heads of the triceps

Question 20

What nerve are we worried about with humural fractures of the shaft?

Answer 20

radial nerve as it spirals around the mid-humerus

Question 21

Where do we find the circumflex artery?

Answer 21

Transits the triangular space

Question 22

Describe the relationship of the suprascapular a. and n. with the suprascapular (aka superior transverse scapular) ligament.

Answer 22

the artery goes over the ligament; the nerve goes under it

Question 23

What is the largest branch of the axillary arteries?

Answer 23

Subscapular artery

Question 24

Question 25

Question 26

Answer 26

Question 27

Saturday night Palsy?

Answer 27

associated with someone who sleeps off a hangover with the back of the arm draped over the edge of the bed or bedrail. They awaken with the so-called “Saturday night palsy.” This palsy manifests itself as a radial nerve loss: inability to raise the wrist - or a “wrist-drop”.

Question 28

What nerve innvervates the deltoid

Answer 28

innervated by axillary nerve

Question 29

What does the deltoid do?

Answer 29

It abducts the shoulder, flexes it and extends it.

Question 30

What innvervates the supraspinatus

Answer 30

innervated by the suprascapular nerve

Question 31

What does the supraspinatous do?

Answer 31

aBduction of the armand stabilizes the humerus

Question 32

What innervates the supraspinatus

Answer 32

innervated by suprascapular nerve

Question 33

What does the infraspinatus do?

Answer 33

It laterally rotates the arm and stabilizes the humerus

Question 34

Where does the teres major attach

Answer 34

Goes from the posterior aspect of the inferior angleof the scapula. Inserts on the intertubercular sulcus of the humerus

Question 35

What does the Teres Major do?

Answer 35

teres major - rotates the shoulder joint laterally in combination with the infraspinatus

Question 36

What innervates the teres major

Answer 36

Innervated by the lower subscapular nerve

Question 37

Innervation of the teres minor

Answer 37

innervated by axillary nerve

Question 38

Action of the Teres minor

Answer 38

laterally rotates the arm and stabilizes the humerus

Question 39

Teres minor attachments

Answer 39

goes from the lateral border of the scapula to the greater tuburcle of the humerus

Question 40

Triangular space

Answer 40

Borders:

Teres major inferiorly

Long head of the triceps laterally

Medial is teres minor

Question 41

What makes up the quadrangular space?

Answer 41

Subscapularis & teres minor (superior), teres major (inferior), long head of the triceps (medial), and surgical neck of the humerus (lateral).

Question 42

What is the Blood Supply of the deltoid

What is the innervation of the deltoid?

Answer 42

deltoid branch of thoraco-acromial artery

posterior circumflex humeral artery

axillary nerve