Final answer:
The biceps located just lateral to the pec insertion is the biceps brachii muscle. These muscles are in different anatomical regions. The biceps brachii is located in the anterior compartment of the upper arm. It has two heads (hence "biceps"), a long head, and a short head.
Step-by-step explanation:
The biceps located just lateral to the pec insertion is the biceps brachii muscle. The biceps brachii is a two-headed muscle that crosses the shoulder and elbow joints to flex the forearm while assisting in supinating it and flexing the arm at the shoulder. For example, when you perform a bicep curl, the biceps brachii is responsible for flexing the forearm, bringing the hand closer to the shoulder.
The biceps brachii muscle is not located just lateral to the pectoralis major muscle insertion. The pectoralis major is a large muscle of the chest, and the biceps brachii is a muscle of the upper arm. These muscles are in different anatomical regions. The biceps brachii is located in the anterior compartment of the upper arm. It has two heads (hence "biceps"), a long head, and a short head. The short head of the biceps brachii is located on the lateral side of the humerus, but it is not directly lateral to the insertion of the pectoralis major. If you are referring to another muscle or have a specific context, please provide more details for a more accurate response.