Scapula and Pectoral Regions Flashcards
What are the bones of the pectoral girdle?
- Clavicle
- Scapula
- Humerus
What are the landmarks of the clavicle?
Acromial end - lateral
Sternal end - medial
Shaft
Conoid tubercle
Depression for costoclavicular ligament (posteriormedially)
What are the joints of the pectoral girdle?
- Sternoclavicular joint
- Acromioclavicular joint
- Glenohumeral joint
- Scapulothoracic plane (not really)
What ligament attaches to the conoid tubercle of clavicle?
Conoid ligament
What are the landmarks of the scapula? (15)
Glenoid fossa
Supraglenoid tubercle
Infraglenoid tubercle
Suprascapular notch
Neck
Spine
Acromion process
Coracoid process
Superior angle
Inferior angle
Lateral border
Medial border
Supraspinous fossa
Infraspinous fossa
Subscapular fossa
What originates at the supraglenoid tubercle of the scapula?
Biceps Brachii Long Head
What originates at the infraglenoid tubercle of the scapula?
Triceps brachii long head
What ligament encloses the suprascapular notch? What else is in this notch?
Superior trasnverse scapular ligament encloses notch into a foramen
Suprascapular artery runs superior to ligament and Suprascapular nerve can get trapped in foramen
What are the landmarks of the humerus? (14)
Head
Anatomical Neck
Surgical Neck
Greater tubercle
Lesser tubercle
Intertubercular groove
Shaft
Deltoid tuberosity
Radial groove
Medial epicondyle
Lateral epicondyle
Olecranon fossa
Coronoid fossa
Trochlea Capitulum
Where is the anatomical neck of the humerus?
Between the articular surface of the head of the humerus and the greater and lesser tubercles. Junction between proximal epiphyses and diaphysis
Where is the surgical neck of the humerus?
Distal to greater and lesser tubercles. Inferior to anatomical neck
What runs in the intertubercular groove of the humerus?
Biceps brachii long head tendon
Where is the radial groove of the humerus and what runs through it?
Lateral and distal to deltoid tuberosity. Radial nerve runs through it
Stenoclavicular Joint
Saddle synovial joint
Allows rotation along long axis of clavicle
Provides shock absorption for forces from upper to limb to trunk
Accompanies all scapular motion
What ligaments are part of the sternoclavicular joint?
Sternoclavicular ligament (anterior and posterior)
Costcoclavicular ligament
Interclavicular ligament
Acromioclavicular Joint
Plane synovial joint
Weak
Allows minor rotation and translation to facilitate scapular and clavicular rotation
What happens when the acromioclavicular joint is dislocated?
Shoulder separation
What ligaments are part of the acromioclavicular joint?
Acromioclavicular ligament
Coracoclavicular ligament (strong) –> includes conoid and trapezoid ligament
Glenohumeral Joint
Ball and socket synovial joint
Facilitates mobility at cost of stability
What ligaments are part of glenohumeral joint and where do they originate from?
Ligaments originate from glenoid labrum.
Glenohumeral ligaments (superior, middle, inferior)
Coracohumeral ligament
Transverse humeral ligament –> holds tendon of biceps brachii within groove
Coracoacromial ligament - reinforces joint, prevent dislocation
What is the scapulothoracic plane?
Respresents a fascial plane between muscles surrounding the scapula and muscles of the thoracic wall. Motion occurs with rotation of scapula
What are the anterior extrinsic muscles?
- Pectoralis Major
- Pectoralis Minor
- Subclavius
- Serratus Anterior
What is the origin, insertion, action and innervaton of Pectoralis Major?
Origin:
Clavicular head - 1/3 of clavicle
Sternocostal head - sternum and costal cartilages 1-6
Abdominal head - Aponeurosis of external oblique
Insertion: Lateral lip of intertubercular groove
Action:
Clavicular head - flexes arm
Sternocostal head - extends arm from flexed position
Whole muscle - adducts and medially rotates arm
Innervation: Medial and lateral pectoral nerve
What is the origin, insertion, action and innervaton of Pectoralis Minor?
Origin: Ribs 3-5
Insertion: Coracoid process
Action: Protract scapula and elevate ribs when scapula fixed
Innervation: Medial pectoral nerve