Pectoral Girdle Flashcards
How is the clavicle attached to the sternum?
At the synovial acromioclavicular joint at the sternum
What is the clavicle?
The collar bone
What is the scapula?
The shoulder blade between ribs 2 and 7
How is the scapula attached to the pectoral girdle?
By deep and superficial muscles on the medial border and muscles attach at the spine
Why is the glenohumeral joint unstable?
Because the head of the humerus is 4x bigger than the bony socket
How is the instability of the glenohumeral joint overcome?
By the presence of fibrocartilage labrum which extends the actual size of the joint
The loose fibrous capsule allows range of movement
Ligamentous thickening gives stability (corahumeral ligament)
Where does the corahumeral ligament go from?
The coracoid process to the humerus
What muscles are responsible for the stability of the glenohumeral joint?!
The rotator cuff muscle (4 muscles) which contract together to stabilise the joint
What movements can the elbow produce?
Flexion (bringing into the body) and extension (bringing lower arm down)
At the distal part of the humerus, what articulates with the radius and ulna?
Medial condyle trochlea > ulna
Lateral condyle captilum > radius
What strengthens the articulations between the humerus and the radius and ulna?
Collateral ligaments strength the fibrous capsule around the joint to allow it to be fixed in extension (carrying)
What is the movement of the radius and ulna in supnation and pronation?
in pronation the distal end of the radius move in debt of the ulna (supnation is reverse)
What are the three elements of the radioulnar joint?
Superior radioulnar joint
Inferior radioulnar joint
interosseus membrane
In the superior radioulnar joint what is present?
An articular ligament around the head of the radius
In the inferior radioulnar joint what is present?
The ulna is covered in an articular disc that contacts the radius
