Pectoral Region & Axilla Practice Flashcards

Vocabulary terms and definitions covering the osteology, joints, neurovasculature, musculature, and clinical pathologies of the pectoral region and axilla.

Pectoral Girdle

A structure composed of the clavicle and scapula that suspends the upper limb from the thorax.

Sternal end

The round, medial end of the clavicle that articulates with the sternum.

Acromial end

The flat, lateral end of the clavicle that articulates with the scapula.

Subclavian groove

A feature located on the inferior surface of the clavicle's shaft.

Glenoid cavity

A feature of the scapula that articulates with the humerus.

Coracoid process

A finger-like projection on the anterior aspect of the scapula, superior to the glenoid cavity.

Fracture of the clavicle

An injury most commonly occurring in the middle third segment, characterized by shortening of the bone, drooping of the shoulder, and bulging skin.

Sternoclavicular (SC) Joint

A saddle-type synovial joint that allows protraction, retraction, elevation, depression, and axial rotation of the clavicle.

Acromioclavicular (AC) Joint

A plane-type synovial joint whose primary movement is the rotation of the clavicle about its longitudinal axis.

Shoulder (AC Joint) Separation

An injury resulting from a blow to the superior aspect of the acromion, involving tears to the acromioclavicular and sometimes coracoclavicular ligaments.

Axillary artery

A continuation of the subclavian artery that begins at the lateral border of the $1st$ rib and is divided into three parts relative to the pectoralis minor muscle.

Superior thoracic artery

The single branch emerging from Part $1$ of the axillary artery, supplying the subclavius and the first two intercostal spaces.

Thoracoacromial artery

A branch of Part $2$ of the axillary artery that provides blood supply via pectoral, clavicular, acromial, and deltoid branches.

Lateral thoracic artery

A branch of Part $2$ of the axillary artery that supplies the serratus anterior muscle.

Subscapular artery

A branch of Part $3$ of the axillary artery that divides into the circumflex scapular and thoracodorsal arteries.

Cephalic vein

A superficial vein that drains the lateral aspect of the upper limb.

Basilic vein

A superficial vein that drains the medial aspect of the upper limb.

Median cubital vein

A vein anterior to the elbow that joins the cephalic and basilic veins; it is a common site for venipuncture and IV access.

Long thoracic nerve

A nerve arising from roots $C5-C7$ that innervates the serratus anterior muscle.

Suprascapular nerve

A nerve originating from the superior trunk ($C5, C6$) that innervates the supraspinatus and infraspinatus muscles.

Musculocutaneous nerve

A terminal branch of the brachial plexus ($C5-C7$) that innervates muscles in the anterior compartment of the arm and skin on the lateral forearm.

Median nerve

A terminal branch ($C5-T1$) that innervates most flexors in the anterior forearm, thenar muscles, and the lateral two lumbricals.

Ulnar nerve

A terminal branch ($C8, T1$) that innervates most intrinsic hand muscles and skin on the medial hand.

Radial nerve

A terminal branch ($C5-T1$) that innervates all muscles in the posterior compartments of the arm and forearm.

Axillary nerve

A terminal branch ($C5, C6$) that innervates the deltoid and teres minor muscles.

Pectoralis Major

A muscle that originates from the sternum, clavicle, and costal cartilages $1-6$ and functions to adduct and internally rotate the shoulder.

Pectoralis Minor

A muscle originating from ribs $3-5$ that inserts on the coracoid process and stabilizes the scapula against the thoracic wall.

Serratus Anterior

A muscle that protracts and stabilizes the scapula; it is famously referenced by the mnemonic '$5, 6, 7$ are the wings to heaven'.

Subclavius

A small muscle originating from the $1st$ rib that depresses and anchors the clavicle.

Erb Palsy

A lesion of the superior trunk ($C5, C6$) resulting in a 'waiter’s tip' posture characterized by an adducted, internally rotated shoulder and extended elbow.

Klumpke Palsy

A lesion of the inferior trunk ($C8, T1$) resulting in a 'total claw' hand deformity and potential Horner’s syndrome.

Saturday Night Palsy

An injury to the radial nerve in the axilla caused by compression, resulting in wrist drop and impaired extension of the elbow and digits.

Winged Scapula

A clinical condition caused by a lesion of the long thoracic nerve, resulting in protrusion of the medial border of the scapula.

Subareolar lymphatic plexus

A network of lymph vessels where lymphatic drainage from the breast typically initiates.