See It · The Muscular System

Muscular System Walkthrough

How skeletal muscles pull on bones, how they are named, and what the major muscles of the head, trunk, arm and leg do. Go at your own pace. Nothing here is graded.

Speed

Think of it like this

Quick check

Wrong answers are fine here. Read why, then try again.

Dr. Akash Garg · See It: Anatomy & Physiology · Chapter 11, The Muscular System (OpenStax Anatomy & Physiology 2e) · Use the left and right arrow keys to move between steps. Practice next in the Muscle System Lab.
Diagrams are simplified and not to scale. Muscles are drawn as single bands between their origin (O) and insertion (I); many real muscles have several heads and broad attachments. Movements are slowed down and exaggerated so you can watch them, and the lever ratios are those of the drawings, not measured values. Elbow flexion follows the textbook example (biceps brachii as prime mover, brachialis as synergist). In the wrist drawing the flexor and extensor origins are shown on the palm and back sides for clarity; they really start on the medial and lateral epicondyles.