"Shoulder and Arm" Questions Flashcards
What are the 3 bones from the shoulder girdle to the elbow?
Scapula
Clavicle
Humerus
What are the landmarks at the neck of the humerus?
Greater tubercle (laterally) Lesser tubercle (medially) Intertubercular sulcus (in between)
What is the name of the joint between the acromion and the clavicle?
Acromioclavicular joint
What are the two ends of the clavicle?
Acromial (at acromion)
Sternal (at sternum)
What are the borders and angles of the scapula?
Superior, lateral and medial borders
Inferior and superior angles (lateral “angle” is the acromion)
What are the two lateral extensions of the scapula where lots of muscles attach?
Coracoid process (anterior, looks like a hook) Acromion (posterior, articulates with clavicle)
What is the name of the space where the humerus articulates with the scapula?
Glenoid fossa/cavity
glenohumeral joint
What are the fossae of the scapula?
1 anterior 2 posterior
Anterior = subscapular fossa
Posterior divided by scapular spine into supraspinous fossa and infraspinous fossa
Where is the suprascapular notch?
Between superior angle of the scapula and the coracoid process (little dip)
Where is the head and neck of the scapula?
Laterally
Head is the lip of the glenoid cavity
Neck is just medial to that below the acromion
What are the 3 joints associated with the scapula?
Gleno-humeral joint
Acromio-clavicular joint
Scapulo-thoracic joint (physiological “joint” with chest wall via muscles)
How do you identify the orientation of a random clavicle bone?
There is a sternal and an acromial end and shaft is divided into medial 2/3rd lateral 1/3rd
Use the inferior surface markings
- impression for costoclavicular ligament is close to sternal end on inferior surface
- subclavian groove (for subclavius muscle) is around midpoint of inferior surface of the shaft)
- conoid tubercle at acromial end
- trapezoid line at acromial line (ridge on underside of acromial end)
Acromial end is usually slightly fatter and sternal end more cylindrical
What attaches at the conoid tubercle and the trapezoid line?
Conoid = coracoclavicular ligament Trapezoid = trapezoid ligament
What are the 4 nerves in contact with the humerus?
Axillary
Radial
Ulnar
Median
How can the median nerve be damaged?
Runs anterior to distal humerus
- damaged by fractures/dislocations around the elbow joint
How can the axillary nerve be damaged?
Winds around surgical neck of the humerus
- can be damaged in shoulder dislocations
How can the ulnar nerve be damaged?
Runs posterior to the medial epicondyle
- can be damaged in fractures/dislocations around the elbow joints
How can the radial nerve be damaged?
Runs in the radial groove
- can be damaged by fractures of the humeral shaft
Where are the two necks and the head of the humerus and which neck is more commonly damaged?
Head of humerus (inserts into glenoid cavity)
Anatomical neck - lip of bone just after head
Surgical neck - area between expanded head and narrow shaft, quite weak, easier to fracture
Surgical is more commonly fractured than anatomical.
Where is the radial groove and what is it formed from?
Wraps around to the posterior of the humerus
- starts as intertubercular sulcus (groove)
What is the ridge of bone called on the shaft of the humerus?
Deltoid tuberosity
What muscles attach to the intertubercular groove and where on it do they attach?
Pec. major attaches to lateral lip
Teres major attaches to medial lip
Lat. dorsi attaches to the floor
What joints is the pectoral girdle made up of?
Sterno-clavicular joint Acromio-clavicular joint Gleno-humeral joint Scapulo-thoracic joint (all of these are synovial joints except scapulo-thoracic)
What are the ligaments involved in the sterno-clavicular joint?
Sterno-clavicular ligaments
What are the ligaments involved in the acromio-clavicular joint?
- Acromio-clavicular ligament
- Coraco-clavicular ligament (conoid + trapezoid ligs.)
- Coraco-acromial ligament
What are the ligaments involved with the shoulder joint capsule? (glenohumeral joint)
- Gleno-humeral ligament (strengthens anterior capsule part)
- Coraco-humeral ligament (strengthens superior capsule part)
- Transverse humeral ligament (holds tendon of long head of the bicep in intertubercular sulcus)
Which muscles cause flexion at the shoulder joint?
Pec. major (clavicular head)
Deltoid (anterior fibres)
Coraco-brachialis
Biceps brachii