Glossary

Locomotion and Movement

Glossary

Acetylecholine – A neurotransmitter found throughout the nervous system.

Actin – A protein found in the cytoskeleton and muscle cells; it is the principal constituent of the thin filament.

Adenosine triphosphate(ATP) – A nucleotide molecule consisting of adenine, riboseand three phosphate molecules. It plays a central role in energy exchange in biological systems.

Cartilage – A firm, elastic connective tissue produced by the cells,called chondrocytes.

Exoskeleton – Skeletal elements are located upon body surface or in the skin (Example: Shells of snails in inverbrates, Hair claw and nails in vertibrates.

Endoskeleton – Skeletal elements are located inside the organisms with muscles outside. Found in skeletal system of vertibrates

Lever system – Movement takes place along the joints which act as fulcrum of the lever. One can observe functioning of all the three types of levers in the human skeleton.

Mesoderm – The middle embryonic germ layer. It gives rise to the muscular, skeletal, urogenital and circulatory system.

Motor neuron – A motor neuron that transmits nervous impulses from the spinal cord to effectors.

Myoglobin – Heme containing protein that binds molecular oxygen in muscle cells.

Myosin – A protein found in muscle cells that function in muscle contaction. It is present in thick filaments of muscles, known as myosin fibres

Sarcolemma – Muscle cell membrane capable of propagating action potentials

Sarcomere – The functional contractile unit of striated muscle.

Sarcoplasmic reticulum – The endoplasmic reticulum of a muscle cell. It envelopes myofibrils

Tendon – A fibrous connective tissue that connects a bone to a muscle