Upper Limb 1 - Anatomy Study Guide PDF

Anatomy 534 Upper Limb 1 60 The Quadrangular and Triangular Spaces The configuration of the muscles below the shoulder allow a number of structures to pass from anterior to posterior regions of the axilla and arm. The quadran...

Anatomy 534 Upper Limb 1 60 The Quadrangular and Triangular Spaces The configuration of the muscles below the shoulder allow a number of structures to pass from anterior to posterior regions of the axilla and arm. The quadrangular space: transmits the axillary n. and posterior circumflex a. The triceps hiatus medial to the shaft of the humerus: transmits the radial n. and profunda brachii a. The triangular space inferior to the quadrangular space: passes the circumflex scapular br. of the subscapular a. Axillary Artery The axillary a. is a continuation of the subclavian a. It begins at the lateral edge of R1 and becomes the brachial a. as it passes the lower border of the teres major The axillary a. is divided into 3 parts by the overlying pectoralis minor m. The number of the division is equivalent to the number of branches from that division: Anatomy 534 Upper Limb 1 61 - Branches from the first part: - superior thoracic artery supplies the pectoralis major & minor - Branches from the second part: - thoracoacromial artery is a short trunk that breaks up to supply the pectoral, acromial, clavicular and deltoid regions - lateral thoracic artery contributes substantially to the breast - Branches from the third part: - subscapular artery is the largest branch of the axillary a. and gives rise to numerous muscular branches that form an anastomosis around the scapula - the anterior and posterior circumflex humeral aa. form an anastomotic circle around the surgical neck of the humerus. The anterior is small. The posterior extends through the quadrangular space with the axillary n. to supply the shoulder joint and surrounding muscles