Upper limb gross anatomy 1: Pectoral girdle and shoulder

Question 1

What is the function of the clavicle?

Answer 1

A strut that holds the arm clear of the trunk, thus increasing the range of movement of the upper limb.

Question 2

How is the scapula connected to the axial skeleton?

Answer 2

Via the acromioclavicular joint and by muscles.

Question 3

Where does the pectoral girdle articulate medially with the trunk?

Answer 3

At the clavicle

Question 4

What is the most common type of fracture upon falling on an outstretched hand and why?

Answer 4

Clavicle - force of the fall is transmitted to the clavicle.

Question 5

Describe the basic structure of the clavicle.

Answer 5

Concave in lateral one third, convex in medial two thirds.

Question 6

Why is the clavicle convex in the medial two thirds?

Answer 6

To allow the passage of the neurovascular bundle supplying the upper limb.

Question 7

Which ribs lie under the scapula?

Answer 7

2-7

Question 8

What structure divides the supraspinous and infraspinous fossae of the scapula?

Answer 8

The spine of the scapula.

Question 9

What are the origins of the trapezius?

Answer 9

Superior nuchal line, external occipital protuberance, medial margin of the ligamentum nuchae, spinous processes of C7-T12 and the related supraspinous ligaments.

Question 10

What are the insertions of the trapezius?

Answer 10

Superior edge of the crest of the spine of the scapula, acromion, posterior border of lateral one-third of clavicle.

Question 11

What movements are achieved by the upper fibres of the trapezius?

Answer 11

Elevates the scapula.

Question 12

What movements are achieved by the middle fibres of the trapezius?

Answer 12

Retract the scapula.

Question 13

What movements are achieved by the lower fibres of the trapezius?

Answer 13

Depress the scapula.

Question 14

What movements are achieved by all of the fibres of the trapezius working together?

Answer 14

Rotation of the glenoid cavity superiorly.

Question 15

What is the nerve supply to the trapezius?

Answer 15

Motor - spinal part of the accessory nerve (CNXI)

Sensory (proprioception) - anterior rami of C3-4

Question 16

Where does latissimus dorsi attach to the humerus?

Answer 16

Floor of intertubular sulcus of humerus.

Question 17

What are the actions of latissimus dorsi?

Answer 17

Extends, adducts and medially rotates humerus; raise body towards arms during climbing.

Question 18

What are the axial attachments of levator scapula?

Answer 18

Posterior tubercles of transverse processes of C1-4.

Medial border of scapula superior to root of scapular spine.

Question 19

What is the nerve supply to levator scapula?

Answer 19

Dorsal scapular (C4-5) and cervical (C3-4) nerves.

Question 20

What are the axial attachments of rhomboid minor?

Answer 20

Proximal: Nuchal ligament; spinous processes of C7 and T1.

Distal: Smooth triagular area at medial end of scapular spine.

Question 21

What is the nerve supply to rhomboid major?

Answer 21

Dorsal scapular nerve (C4-5)

Question 22

What are the axial attachments of rhomboid major?

Answer 22

Proximal: Spinous processes of T2-5.

Distal: medial border of scapula from level of spine to inferior angle

Question 23

What is the nerve supply to rhomboid minor?

Answer 23

Dorsal scapular nerve (C4-5)

Question 24

What are the actions of levator scapulae?

Answer 24

Elevates scapula and rotates the glenoid cavity inferiorly by rotating scapula

Question 25

What are the actions of rhomboid major and minor?

Answer 25

Retract scapula and rotate glenoid cavity inferiorly; fix scapula to thoracic wall.

Question 26

What are the origins of deltoid?

Answer 26

Inferior edge of the crest of the scapular spine Lateral margin of the acromion Anterior border of the lateral 1/2 of clavicle

Question 27

What is the insertion of deltoid?

Answer 27

Deltoid tuberosity of humerus.

Question 28

What are the actions of deltoid as a whole?

Answer 28

Abduction of the arm.

Question 29

What are the actions of the anterior fibres of deltoid?

Answer 29

Assist pectoralis major in flexing the arm.

Question 30

What are the actions of the posterior fibres of deltoid?

Answer 30

Assist latissimus dorsi in extending the arm.

Question 31

What is the innervation of deltoid?

Answer 31

Axillary nerve

Question 32

What is the proximal attachement of supraspinatus?

Answer 32

Supraspinous fossa of scapula.

Question 33

What is the distal attachment of supraspinatus?

Answer 33

Superior facet of greater tubercle of humerus.

Question 34

What is the nerve supply to supraspinatus?

Answer 34

Supracapsular nerve C4-6

Question 35

What is the proximal attachment of infraspinatus?

Answer 35

Infraspinous fossa of scapula.

Question 36

What is the distal attachment of infraspinatus?

Answer 36

Middle facet of greater tubercle of humerus.

Question 37

What is the nerve supply to infraspinatus?

Answer 37

Supracapsular nerve

Question 38

What are the main actions of supraspinatus?

Answer 38

Initiates and assists deltoid in abduction of arm and acts as with rotator cuff muscles.

Question 39

What are the actions of infraspinatus?

Answer 39

Laterally rotates arm; acts with rotator cuff muscles.

Question 40

What is the proximal attachment of teres minor?

Answer 40

Middle part of lateral border of scapula

Question 41

What is the distal attachement of teres minor?

Answer 41

Middle facet of greater tubercle of humerus.

Question 42

What is the nerve supply to teres minor?

Answer 42

Axillary nerve C5-6

Question 43

What are the main actions of teres minor?

Answer 43

Laterally rotates arm and acts with rotator cuff muscles.

Question 44

What are the proximal attachments of teres major?

Answer 44

Posterior surface of inferior angle of scapula.

Question 45

What is the distal attachment of teres major?

Answer 45

Medial lip of inter-tubercular sulcus of humerus.

Question 46

What is the nerve supply to teres major?

Answer 46

Lower subcapsular nerve C5-6

Question 47

What are the functions of teres major?

Answer 47

Adducts and medially rotates arm.

Question 48

What are the proximal attachments of subscapularis?

Answer 48

Subscapular fossa (most anterior surface of fossa.

Question 49

What is the distal attachement of subscapularis?

Answer 49

Lesser tubercle of humerus.

Question 50

What is the nerve supply to subscapularis?

Answer 50

Upper and lower subcapsular nerves C5-7

Question 51

What are the main actions of subscapularis?

Answer 51

Medially rotates arm as part of rotator cuff, helps hold the head of the humerus in the glenoid cavity.

Question 52

What is the mnemonic that helps you recall the attachments of the rotator cuff muscles?

Answer 52

From greater tubercle to lesser tubercle: Teres minor Infraspinatus Supraspinatus Subscapularis

Question 53

What are the four borders of the quadrangular space?

Answer 53

Superiorly: teres minor Inferiorly: teres major Medially: long head of triceps brachii Laterally: humerus

Question 54

Which artery and nerve are located within the quadrangular space?

Answer 54

Axillary nerve and posterior circumflex artery

Question 55

What movements are possible at the glenohumeral joint and which muscles are involved?

Answer 55

Flexion - clavicular deltoid Extension - spinal deltoid Medial rotation - deltoid, teres major, subscapularis Lateral rotation - spinal deltoid, infraspinatus, teres major Abduction - acromial deltoid Adduction - teres major

Question 56

Which muscle is responsible for the initiation of abduction at the glenohumeral joint?

Answer 56

Supraspinatus

Question 57

What are the attachments of the long head of biceps brachii?

Answer 57

Arises from the supraglenoid tubercle, crosses head of humerus within cavity of glenohumeral joint.

Question 58

What are the attachments of the long head of triceps brachii?

Answer 58

Infraglenoid tuberosity

Question 59

Which muscles produce protraction of the scapula?

Answer 59

Pectoralis major, pectoralis minor and serratus anterior

Question 60

Which muscles produce retraction of the scapula?

Answer 60

Trapezius (middle fibres), rhomboid major and minor and latissimus dorsi

Question 61

Contraction of which muscles produce elevation of the scapula?

Answer 61

Trapezius (superior fibres), levator scapula, ?serratus anterior, ?rhomboids

Question 62

Which muscles contract to produce depression of the scapula?

Answer 62

Pectoralis major, latissimus dorsi, trapezius (inferior fibres)

Question 63

Which muscles produce medial rotation of the scapula?

Answer 63

latissimus dorsi, pectoralis major, teres major, subscaplaris