my(o)-

Muscle.

Greek mus, mu‑, mouse or muscle.

Myoglobin is a red protein which carries and stores oxygen in muscle cells; a myopathy (Greek patheia, suffering) is a disease of muscle tissue; the myocardium is the muscular tissue of the heart; myalgia (Greek algos, pain) is pain in a muscle or group of muscles; myasthenia (Greek asthenēs, weak) is a condition causing abnormal weakness of certain muscles.