Locomotion • change in position of an organism • Survival Value of Locomotion 1. Get food and shelter 2. Escape from predators 3. Move to regions better suited to survival 4. Find mates 5. Move away from toxic wastes
Functions of the skeleton 1. Supporting framework for internal organs and tissues. 2. Anchorage sites for muscle action. 3. Protects the internal organs. 4. Provides leverage for body movement. 5. Blood cells are produced in the bone marrow.
The bones also store minerals. • Cartilage: tough, fibrous, elastic connective tissue
Cartilage Functions a. Pliable support b. Flexibility of joints c. Cushioning of joints • ** Cartilage makes up most of the embryo's skeleton. ** • Most of this cartilage changes to bone by adulthood.
Ligaments: connect bones to bones (joints) tough and elastic • Tendons: tough inelastic fibrous cords which attach muscles to bones
Malfunctions of the Locomotion System • arthritis: joint inflammation • tendonitis: tendon inflammation at bone junctures (a common condition in athletes)
Muscles • Only body tissue able to contract • create movement by flexing and extending joints • Body energy converters (many muscle cells contain many mitochondria)
Smooth Muscle • (involuntary) "viscera" • Smooth in appearance, involuntary in action • Slowly contracting -- but contractions are long in duration • lines blood vessels, alimentary canal, and body openings
Cardiac Muscle • (involuntary striated) • resembles skeletal muscle with lined appearance, but is involuntary • composes the hardest working muscle, the heart
Skeletal muscle • (voluntary, striated) • Voluntary in action • contain many striped long fibers called striations • found in association with skeletal bones • The nervous system interacts with skeletal muscles to produce motion
** Violent muscle contractions require much oxygen. ** • If oxygen is not available muscle fatigue will set in. • "Muscle fatigue"-- results from oxygen debt -- lactic acid accumulates in skeletal muscles • rest restores the oxygen balance • “Lactic acidosis” – it is more or less a muscle cramp for the entire body or a certain muscle.
Organisms have a great variety of locomotion structures. • Name some of them: