Audio LecturePro Feature Teres Major 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x The teres major is an intrinsic muscle of the shoulder region. It forms the inferior border of the quadrangular space – the space that the axillary nerve and posterior circumflex humeral artery pass through to reach the posterior scapular region. Attachments: Originates from the posterior surface of the inferior angle of the scapula. It attaches to the medial lip of the intertubercular groove of the humerus. Actions: Adduction, extension and medial rotation of the upper limb at the shoulder. Innervation: Lower subscapular nerve. Blood supply: Thoracodorsal artery, posterior circumflex humeral artery By TeachMeSeries Ltd (2026) Fig 1The deltoid and teres major 3D ModelPro Feature You've Discovered a Pro Feature Access our 3D Model Library Explore, cut, dissect, annotate and manipulate our 3D models to visualise anatomy in a dynamic, interactive way. Learn More Dissection AtlasPro Feature Prosection of the posterior shoulder region. The axillary nerve and posterior circumflex humeral artery can be seen passing through the quadrangular space Prosection of the posterior shoulder region. The axillary nerve and posterior circumflex humeral artery can be seen passing through the quadrangular space You've Discovered a Pro Feature Access our Dissection Image Library Enhance your understanding with high-resolution dissection images showcasing real-life anatomy. Learn More In gratitude to our body donorsLearn more In gratitude to our body donors We are deeply grateful to the individuals who chose to donate their bodies for the advancement of medical education. Their generosity makes these images possible and provides students and healthcare professionals with an invaluable opportunity to study human anatomy. We recognise the profound contribution made by each donor and their families, and we use these images with the dignity and respect their gift deserves. Acknowledge Frequent questions What is the teres major muscle? The teres major is an intrinsic muscle located in the shoulder region, serving as the inferior boundary of the quadrangular space. This space allows the passage of the axillary nerve and the posterior circumflex humeral artery. Where does the teres major muscle originate and insert? The teres major originates from the posterior surface of the inferior angle of the scapula and inserts onto the medial lip of the intertubercular groove of the humerus. This positioning contributes to its role in upper limb movement. What actions are performed by the teres major? The teres major facilitates adduction, extension, and medial rotation of the upper limb at the shoulder joint. These actions are essential for various arm movements and stability. Which nerve innervates the teres major muscle? The teres major is innervated by the lower subscapular nerve. This innervation is crucial for the muscle's function and coordination during upper limb movements. What is the blood supply to the teres major? The teres major receives its blood supply primarily from the thoracodorsal artery and the posterior circumflex humeral artery. These vessels ensure adequate oxygenation and nutrient delivery to the muscle. Rate This Article