quadrangular space


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qua·dran·gu·lar space

musculotendinous formation providing passageway for the axillary nerve, posterior humeral circumflex artery, and accompanying veins as they run from the axilla to the superior posterior arm; as the neurovascular structures enter the formation anteriorly, it is bounded superiorly by the shoulder joint, medially by the lateral border of subscapularis, laterally by the surgical neck of the humerus, and inferiorly by the tendon of latissimus dorsi; where the vessels exit the formation posteriorly, it is bounded superiorly by the teres minor, medially by the long head of the triceps, laterally by the lateral head of the triceps and inferiorly by the teres major muscle or tendon; as they emerge, most of the neurovascular structures run on the deep surface of the deltoid muscle, which they supply.
Synonym(s): quadrilateral space
References in periodicals archive ?
The posterior humeral circumflex artery (arteria circumflexa humeri posterior, PHCA) stems from the AA at the distal border of the subscapularis (musculus subscapularis) from the proximal segment of the infrapectoral (last, third) part of the AA and runs dorsally into the quadrangular space (foramen humerotrici-pitale, spatium axillare laterale) together with the axillary nerve (nervus axillaris).
Thus, the PHCA could not pass through its usual topographical site - the quadrangular space (foramen humerotricipitale)- but after leaving the trunk, it coursed underneath the fused tendons of the proximal teres major and distal latisssimus dorsi.
The posterior circumflex humeral artery which is a branch of the third part of axillary artery passes through the Quadrangular space or humero tricipital foramen (between Teres major, Teres minor, shaft of humerus and long head of Triceps) along with Axillary nerve.
The posterior circumflex humeral artery descends superficial to the axillary nerve and passed through the quadrangular space.