Answer:
The labels are in the attached image.
Explanation:
In a flexed arm, the biceps brachii contract and the attached tendon pulls radius and ulna upwards. During flexion, the triceps brachii relax.
Upper Arm Muscles and Tendons:
- The biceps brachii, a two headed muscle, joins the upper arm bone, humerus through a tendon.
- Most of the muscle mass of biceps brachii is located anterior to the humerus.
- The triceps, a three headed muscle, possesses three attachments:
- The long head originates from the scapula.
- The lateral head from the proximal region of the humerus
- The medial head from the distal region of the humerus.
- All three converge into one tendon which attaches to the ulna.
