Shoulder Region and Arm I

Question 1

Definition of the pectoral girdle

Answer 1

Bones of appendicular skeleton that connects arms to our sides (clavicle, scapula)

Question 2

Definition of the arm, forearm and upper limb

Answer 2

Between shoulder and forearm at elbow joint

Between arm at the elbow joint to the wrist joint

Between the shoulder joint and the hand

Question 3

What are the 3 main bones that make up the pectoral girdle

What are the 3 main joints in the pectoral girdle and upper limb

Answer 3

Manubrium sterni, clavicle, scapula

Sternoclavicular joint
Acromioclavicular joint
Glenohumeral joint

Question 4

What joint connects the upper limb to the thorax

Why is this the only 1

Answer 4

Sternoclavicular joint

Stability sacrificed for movement

Question 5

Describe the key osteological features on the superior surface of the clavicle

Answer 5

Scapula articualtion
Manubrium articulation

Has a curved tendril shape

Question 6

Describe the key osetological features on the inferior surface of the clavicle

Answer 6

Near the scapula articulation

• Acromial facet
• Trapezoid line (attachment for trapezoid ligament)
• Conoid tubercle (conoid ligament attachment)
• Subclavian groove (attachment for subclavius)

By the manubrium articulation
-Sternal facet

Question 7

What makes the clavicle different from other bones

How does the male clavicle differ from the female clavicle

Answer 7

Long bone with no medullary cavity
Trabecular surrounded by compact bone

1st bone to ossify in embryo but last to finish

Male clavicle is thicker, bigger muscles attach here

Question 8

Describe the 4 ligaments found at the sternoclavicular joint

Describe the 2 joints found between the sternum and ribs

Name the muscle found between the clavicle and R1

Answer 8

Interclavicular ligament
Post and ant sternoclavicular ligament
Costoclavicular ligament

Sternoclavicular joint = synovial saddle joint that acts like a ball and socket
-Has an articular hyaline disc between a joint cavity

Sternal synchondroses (hyaline) between CC and sternum

Subclavius

Question 9

Describe the function of the sternoclavicular ligaments

Answer 9

Ligaments stabilise joints

Ant and post sternoclavicular ligament surrounds the SCJ capsule

Question 10

What is cleidocranial dysostosis

What causes it?

Answer 10

Skeletal defect, affects clavicles and teeth

• Clavicles are v thin/not present
• V disorganized teeth

Cause by RUNX2 gene defect

Question 11

Describe what can happen in a clavicular fracture

What can cause a clavicular fracture

Answer 11

Caused by direct blow/force transmitted from arm

Sternocleidomastoid can pull medial part upwards => skin perforation

Question 12

Describe the key osteological features on the anterior surface of the scapula

Answer 12

Coracoid process anterior to acromion process

Suprascapular notch on superior border

Superior, lateral and medial border
Superior, inferior and lateral angle

Subscapular fossa on body
Neck between coracoid process and body

Question 13

Describe the key osteological features on the posterior surface of the scapula

Answer 13

Acromium process anterior to coracoid process

Spine from acromium process => supraspinous and infraspinous fossa

Superior, lateral and medial border
Superior, inferior and lateral angle

Question 14

Describe the key osteological features on the lateral surface of the scapula

Answer 14

Glenoid cavity between acromium and coracoid process

Glenoid cavity between the superior and inferior angle

Question 15

Describe what happens in a scapular fracture

When does a scapular fracture occur

Answer 15

V thin bone but protected by many layers of muscle
Needs massive force to break it

Check ABCs

Question 16

What is an os acromiale

Answer 16

Acromium develops from 4 separate parts in childhood and fuses by adulthood
Failure of fusion => Os acromion (free fragments)

Question 17

What are the 3 main ligaments found the the acromioclavicular joint

Answer 17

Acromioclavicular ligament,

• articulations lined with fibrocartilage and divided by fibrocartilage articular disc
• incomplete articular disc, no muscles connect articulating bones
• synovial joint

Trapezoid ligament
-attaches to trapezoid line on clavicle

Conoid ligament
-Attaches to conoid tubercle

Trapezoid + coracoid ligament => coracoclavicular ligament

Question 18

What happens in an acromioclavicular joint dislocation

Answer 18

Acromioclavicular ligament torn in a separated shoulder

Question 19

Describe the scapulothoracic joint

What movements are possible here

Answer 19

No bony articulations

Elevation
Depression
Retraction
Protraction
Upwards rotation
Downwards rotation

Question 20

Name the 4 muscles found in the deep posterior axioappendicular region

Answer 20

Levator scapulae
Rhomboid minor
Rhomboid major
Serratus anterior

Question 21

What are the

• attachments
• innervations
• actions associated with the
• levator scapulae
• rhomboid major
• rhomboid minor
• serratus anterior

Answer 21

Levator scapulae

• Post tubercle of C1-4 => medial border
• Dorsal scapular nerve
• Retracts, elevates scapula

Rhomboid minor

• Spinous process of C7-T1 => medial border
• Dorsal scapular nerve
• Retracts, rotates scapula

Rhomboid major

• Spinous processes of T2-5 => medial border
• Dorsal scapular nerve
• Retracts, rotates scapula

Serratus anterior (boxer muscle)

• Medial scapular border => lateral of R1-9
• Long thoracic nerve
• Scapula rotation, elevates arm

Question 22

Describe what happens in winged scapula

How is it treated?

Answer 22

Paralysis of serrates anterior due to lesions to long thoracic nerve

Treated by strength training and physical therapy
Surgery

Question 23

Name the 2 superficial posterior axioappendicular muscles

Answer 23

Trapezius

Latissimus dorsi

Question 24

What are the

• Attachements
• Innervations
• Actions associated with the
• trapezius
• latissimus dorsi

Answer 24

Trapezius

• Occipital skull bone => scapula spine
• Cranial 11
• Sup contracts => elevates
• Middle contracts => retracts
• Inf contracts => depress scapula

Latissimus dorsi

• Lower thoracic, lumbar, sacral spine => ant of humerus
• thoracodorsal nerve
• Extends, adducts, med rot of humerus

Question 25

Describe the key osteological features on the anterior of the humerus

Answer 25

Head (articulates with shoulder joint)
Greater and lesser tubercle (latissimus doris attachment)
Inter tubercular sulcus in between
Deltoid tuberosity (deltoid muscle attaches)

Lateral supraepicondylar ridge

Radial fossa (entry point for radial head) superior to capitulum

Coronoid fossa (articulates with coracoid process on ulna) superior to trochlea

Medial epicondyle (forearm muscle attachment)

Question 26

Describe the key osteological features on the posterior of the humerus

Answer 26

Radial groove (for radial nerve)

Medialsupracondylar ridge

Olecranon fossa (olecranon of ulna articulates here) medial to lateral epicondyle