Final answer:
The two heads of the biceps brachii join and connect to a single tendon that inserts on the radial tuberosity on the forearm, enabling the flexion and supination movements of the forearm and arm.
Step-by-step explanation:
The biceps brachii, a two-headed muscle in the upper arm, plays a crucial role in the movement of the forearm and shoulder. When this muscle contracts, it allows for the flexion of the forearm at the elbow as well as assists in supinating the forearm and flexing the arm at the shoulder. The two muscle heads of the biceps brachii converge and attach to a single tendon of insertion, which is connected to the radius, a bone in the forearm. Specifically, this tendon inserts on the radial tuberosity, a bony prominence on the radius, which allows the biceps brachii to exert its action during muscle contraction.
This mechanism functions in tandem with other muscles, such as the brachialis and brachioradialis, which provide additional force and stability for the forearm's movements. It is also part of a muscular system that works in opposition with the triceps brachii, the muscle responsible for extending the forearm at the elbow joint.