Question

Which muscle is inserted into the floor of the intertubercular sulcus of the humerus?

• A. Latissimus dorsi
• B. Teres major
• C. Pectoralis major
• D. Deltoid

Hint:

Mnemonic: A Lady between two Majors - the Lady (latissimus dorsi) lies in the floor.

Answer 1

The Correct Option is A

Step 1: The intertubercular sulcus (bicipital groove) of the humerus lies between the greater and lesser tubercles. It has three lips that give attachment to three muscles, often remembered as the three muscles of the rotator cuff region surrounding the groove.

Step 2: The three attachments are: pectoralis major on the lateral lip, latissimus dorsi on the floor, and teres major on the medial lip. So the muscle inserting into the floor of the groove is the latissimus dorsi.

Step 3: Why the others are wrong - pectoralis major attaches to the lateral lip (not the floor), and teres major attaches to the medial lip. The deltoid inserts into the deltoid tuberosity on the lateral shaft and is not related to the bicipital groove at all.

Step 4: Hence latissimus dorsi is the correct answer.