Pectoral Girdle Anatomy

Flashcards covering bones, joints, surface anatomy landmarks, ligamentous support, injuries, and anterior muscles of the pectoral girdle.

Appendicular Skeleton

Portion of the skeleton consisting of 126 bones that support the appendages, connected to the axial skeleton to aid in body movement.

Glenoid Labrum

A ring of cartilage that surrounds the outer rim of the glenoid cavity to deepen the socket.

Clavicle

The most common bone fractured in the body; functions to transmit forces from the upper limb to the axial skeleton, provide attachment for muscles, and act as a strut to hold the upper limb free from the trunk.

ABCs of Radiographs

A diagnostic evaluation scheme standing for Alignment (and image quality adequacy), Bone (density and texture), Cartilage (joint space), and Soft tissues (or presence of foreign bodies).

Sternoclavicular (SC) Joint

A joint with small and incongruent contact surfaces that is very stable due to ligament and muscle attachments, representing only 1% of all joint dislocations in the body.

Coracoclavicular Ligaments

Ligaments of the acromioclavicular (AC) joint comprised of the conoid ligament and the trapezoid ligament.

Shoulder Separation

An acromioclavicular (AC) joint dislocation usually caused by a fall on the tip of the shoulder, depressing the acromion.

Coracohumeral Ligament

A passive support at the glenohumeral (GH) joint that helps prevent the humerus from subluxing inferiorly.

Coracoacromial Ligament

A ligament of the glenohumeral (GH) joint that forms a protective arch over the humeral head.

Transverse Humeral Ligament

A ligament that holds the long head of the biceps brachii (LHB) tendon in the intertubercular sulcus.

Shoulder Dislocation

A glenohumeral (GH) joint injury in which anterior dislocation is most common (95-97% of all cases), frequently associated with Axillary nerve injury, glenoid labrum tears, and/or long head of biceps (LHB) tears.

Suprasternal (Jugular) Notch

A surface anatomy landmark located at approximately the T2/3 vertebral level.

Manubriosternal Angle

A surface anatomy landmark located at approximately the T4/5 vertebral level.

Xiphoid Process

A surface anatomy landmark located at approximately the T9 vertebral level.

Pectoralis Major

An anterior pectoral girdle muscle that attaches proximally to the medial half of the clavicle, the anterior surface of the sternum, upper 6 costal cartilages, and external oblique aponeurosis, distally to the lateral lip of the intertubercular groove of the humerus, and is innervated by the Medial Pectoral nerve (C8, T1) and Lateral Pectoral nerve (C5, C6, C7).

Pectoralis Minor

An anterior pectoral girdle muscle originating on ribs 3-5, inserting on the coracoid process of the scapula, innervated by the Medial Pectoral nerve (C8, T1), which pulls the coracoid process forward and downward or elevates the ribs.

Serratus Anterior

An anterior pectoral girdle muscle originating on ribs 1-8, inserting on the medial border of the scapula, innervated by the Long Thoracic nerve (C5, C6, C7) which is uniquely located superficial to the muscle, acting to produce protraction and upward rotation of the scapula.

Subclavius

An anterior pectoral girdle muscle originating on the border of rib 1 and its costal cartilage, inserting on the inferior surface of the middle third of the clavicle, innervated by the Nerve to Subclavius (C5, C6), which depresses the clavicle or elevates the first rib.