Anatomy of Shoulder Complex & Upper Arm Flashcards
slender bone about 6 inches long and shaped like the letter S.
clavicle
How long is the clavicle
6 inches long
Point of weakness & large # of fractures occur in the clavicle
point at which the clavicle changes shape
flat, triangular bone
Scapula
2 major projections of scapula
- spine (hook-like projection)
- coracoid process
above the spine of the scapula
supraspinous fossa
below the spine of the scapula
infraspinous fossa
made up of the head, anatomical neck, greater and lesser tuberosities with a bicipital groove in between
(retains the long tendon of the biceps brachii muscle)
Humerus
3 bones that make up the shoulder complex & upper arm
- clavicle
- scapula
- Humerus
4 articulations of the shoulder complex & upper arm
- Sternoclavicular Joint (SC)
- Acromioclavicular Joint (AC)
- Coracoclavicular Joint (CC)
- Glenohumeral Joint (GH)
proximal end of clavicle with the manubrium of the sternum.
A fibrocartilaginous disk is interposed between the two surfaces.
The SC joint is very weak in bony arrangement but has very strong ligamentous stability
- anterior sternoclavicular
- posterior sternoclavicular
- interclavicular
- costoclavicular
Sternoclavicular Joint (SC)
interposed between proximal end of clavicle w/ the manubrium of the sternum
fibrocartilaginous disk
4 ligaments of the Sternoclavicular Joint (SC)
- Anterior Sternoclavicular
- Posterior Sternoclavicular
- Interclavicular
- costoclavicular
prevents upward displacement of clavicle
anterior sternoclavicular
prevents upward displacement of clavicle
anterior sternoclavicular ligament
posterior sternoclavicular ligament
prevents lateral displacement of clavicle
interclavicular
prevents lateral and upward displacement of clavicle
costoclavicular
gliding articulation of the lateral end of the clavicle with the acromion process.
A weak joint surrounded by a thin, fibrous sleeve and
3 ligaments:
superior and inferior acromioclavicular
the coracoclavicular ligaments
Acromioclavicular Joint (AC)
3 ligaments of the Acromioclavicular Joint (AC)
- superior acromioclavicular
- inferior acromioclavicular
- coracoclavicular
the coracoid process with the clavicle joined by the coracoclavicular ligament (divided into the conoid and the trapezoid parts)
coracoclavicular joint (CC)
the true shoulder joint. Ball and socket joint made up of the round head of the humerus and the glenoid cavity of the scapula.
A fibrocartilagenous rim known as the glenoid labrum deepens the cavity.
Surrounding the articulation is a loose, articular capsule.
Ligamentous reinforcement comes from the superior, middle, and inferior glenohumeral ligaments and the coracohumeral ligament.
Glenohumeral Joint (GH)
Ligamentous reinforcement of the Glenohumeral Joint (GH)
- Superior glenohumeral ligment
- middle glenohumeral ligament
- inferior glenohumeral ligament
- coracohumeral ligament
fibrocartilagenous rim deepens the cavity of the glenohumeral joint (GH)
glenoid labrum
True shoulder joint / Ball & socket joint of the glenohumeral joint is made of
- round head of the humerus
- glenoid cavity of the scapula
5 anterior nerve rami subdivisions create a nerve network known as
Brachial Plexis
Brachial Plexis is made of what spinal nerve segments
C5 - T1
Does the scapula contribute the first 45 degrees of GH motion
NO
Beyond 45 degrees, scapula starts to move in what ratio?
1:2 ratio
1 degree of scapula movement for every 2 degrees of humeral movement
Rotator cuff is made of what muscles
- supraspinatus
- infraspinatus
- subscapular
- teres minor
