Biology Prefixes and Suffixes: my- or myo-

Skeletal Muscle Fiber
This is a colored scanning electron micrograph (SEM) of a skeletal, or striated, muscle fiber. It consists of a bundle of smaller fibers called myofibrils, which are crossed by transverse tubules (green) that mark the division of the myofibrils in to contractile units (sarcomeres). Credit: STEVE GSCHMEISSNER/Science Photo Library/Getty Images

Biology Prefixes and Suffixes: my- or myo-


The prefix (myo- or my-) means muscle.


Myalgia (my-algia) - pain in a muscle.

Myasthenia (my-asthenia) - disorder that causes muscle weakness.

Myoblast (myo-blast) - embryonic cell of the mesoderm germ layer that develops into muscle tissue.

Myocarditis (myo-card-itis) - condition characterized by inflammation of the muscular middle layer (myocardium) of the wall of the heart.

Myocardium (myo-cardium) - the muscular middle layer of the wall of the heart.

Myocele (myo-cele) - protrusion of a muscle through its sheath.

Myoclonus (myo-clonus) - brief involuntary contraction of a muscle or muscle group.

Myocyte (myo-cyte) - cell that comprises muscle tissue.

Myoelectric (myo-electric) - relating to the electrical impulses that generate muscle contractions.

Myofibril (myo-fibril) - long, thin muscle fiber thread.

Myofilament (myo-fil-ament) - myofibril filament composed of actin or myosin proteins.

Myogenic (myo-genic) - originating in or arising from the muscles.

Myogenesis (myo-genesis) - formation of muscle tissue occurring in embryonic development.

Myoglobin (myo-globin) - oxygen storing protein found in muscle cells.

Myogram (myo-gram) - graphical recording of muscle activity.

Myograph (myo-graph) - instrument for recording muscle activity.

Myoid (my-oid) - resembling muscle or muscle-like.

Myolipoma (myo-lip-oma) - type of cancer that consists partly of muscle cells and mostly of adipose tissue.

Myology (myo-logy) - the study of muscles.

Myoma (myo-oma) - benign cancer consisting primarily of muscle tissue.

Myosin (myo-sin) - primary contractile protein in muscle cells that enables muscle movement.

Myositis (myos-itis) - muscle inflammation that causes swelling and pain.

Myotonia (myo-tonia) - condition in which the ability to relax a muscle is impaired.