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. Steve Gschmeissner/Science Photo Library/Getty Images

The prefix myo- or my- means muscle. It is used in a number of medical terms in reference to muscles or muscle-related disease.

Words Beginning With (Myo- or My-)

Myalgia (my-algia): The term myalgia means muscle pain. Myalgia may occur due to muscle injury, overuse, or inflammation.

Myasthenia (my-asthenia): Myasthenia is a disorder that causes muscle weakness, typically of voluntary muscles in the face.

Myoblast (myo-blast): The embryonic cell layer of the mesoderm germ layer that develops into muscle tissue is called myoblast.

Myocarditis (myo-card-itis): This condition is 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): A myocele is a protrusion of a muscle through its sheath. It is also called a muscle hernia.

Myoclonus (myo-clonus): A brief involuntary contraction of a muscle or muscle group is known as myoclonus. These muscle spasms occur suddenly and randomly. A hiccup is an example of a myoclonus.

Myocyte (myo-cyte): A myocyte is a cell that is found in muscle tissue.

Myodystonia (myo-dystonia): Myodystonia is a muscle tone disorder.

Myoelectric (myo-electric): This terms refers to the electrical impulses that generate muscle contractions.

Myofibril (myo-fibril): A myofibril is a long, thin muscle fiber thread.

Myofilament (myo-fil-ament): A myofilament is a myofibril filament composed of actin or myosin proteins. It plays an important role in the regulation of muscle contractions.

Myogenic (myo-genic): This term means originating in or arising from the muscles.

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

Myoglobin (myo-globin): Myoglobin is the oxygen-storing protein found in muscle cells. It is only found in the bloodstream following a muscle injury.

Myogram (myo-gram): A myogram is a graphical recording of muscle activity.

Myograph (myo-graph): The instrument for recording muscle activity is known as a myograph.

Myoid (my-oid): This term means resembling muscle or muscle-like.

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

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

Myolysis (myo-lysis): This term refers to the breakdown of muscle tissue.

Myoma (my-oma): A benign cancer consisting primarily of muscle tissue is called a myoma.

Myomere (myo-mere): A myomere is a section of skeletal muscle that is separated from other myomeres by layers of connective tissue.

Myometrium (myo-metrium): Myometrium is the middle muscular layer of the uterine wall.

Myonecrosis (myo-necrosis): The death or destruction of muscle tissue is known as myonecrosis.

Myorrhaphy (myo-rrhaphy): This term refers to the suture of muscle tissue.

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

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

Myotome (myo-tome): A group of muscles connected by the same nerve root is called a myotome.

Myotonia (myo-tonia): Myotonia is a condition in which the ability to relax a muscle is impaired. This neuromuscular condition may impact any muscle group.

Myotomy (my-otomy): A myotomy is a surgical procedure that involves the cutting of a muscle.

Myotoxin (myo-toxin): This is a type of toxin produced by venomous snakes that causes muscle cell death.