The axillary nerve and the posterior circumflex humeral artery and vein pass through this space (Fig. 7.38).
The triangular space is an area of communication between the axilla and the posterior scapular region (Fig. 7.37). When viewed from the posterior scapular region, the triangular space is formed by: the medial margin of the long head of the triceps brachii, the superior margin of the teres major, and the inferior margin of the teres minor.