Biceps muscle relaxed. 1 and 3: Two heads of the muscle; 2: Muscular portion; 3: Tendon fastening to the fore-arm.

Biceps

Biceps muscle relaxed. 1 and 3: Two heads of the muscle; 2: Muscular portion; 3: Tendon fastening to…

Biceps muscle contracted to raise the fore-arm. 1 and 3: Two heads fastened at the shoulder; 2: Contracting portion; 4: End fastened to the fore-arm.

Biceps

Biceps muscle contracted to raise the fore-arm. 1 and 3: Two heads fastened at the shoulder; 2: Contracting…

A single fiber partly broken and greatly magnified. 1: The delicate fibrous cover unrboken; 2: The muscular substance within, separated.

Fibers

A single fiber partly broken and greatly magnified. 1: The delicate fibrous cover unrboken; 2: The muscular…