Locomotion and Support

1. Locomotion and Support By Charlene, Coco, Bryan

2. Locomotion • Act, ability, or power of moving • The musculoskeletal system gives animals the ability to move • Provides form, support, stability, and movement to eh body

3. Bones • Made of collagen and calcium salts • Bones change shape when osteoblasts (bone-building cells) and osteoclasts (bone-breaking cells) remodel them. • Joints are held together by ligaments • The connective tissue that attach muscles to bones are tendons.

4. Exoskeleton • Encloses the bodies of arthropods • Supports the important internal organs and protects them from being damaged • Insects shed their exoskeleton to increase in size

5. Endoskeleton • Found in all vertebrates • Made up of phosphate and calcium • Important to maintain the body shape, supports the soft-body tissues and protects the internal organs from getting injured • Certain parts store minerals

6. Hydrostatic • Consists of internal body fluids in the confined body cavity • The fluid is held under pressure in compartments and surrounded by muscles • This ensures the shape of soft-bodied organisms like earthwormsand sea anemones.

7. Human Skeleton

8. Axial Skeleton • Is the part of the skeleton that forms an imaginary line down the back bone of the body • Is made out of -skull -vertebral column -sternum and ribs

9. Appendicular Skeleton • Scapula- flat, triangular-shaped bone that forms the basis of the shoulder • Humerus- articulates with the scapula to form a ball-end socket joint at the shoulder • Ulna- longer bone of the forearm that articulates with the humerus • Radius- flattened, slightly curved bone in the hand • Pelvic Girdle- provides connection between the axial skeleton and hind limbs • Femur- largest bone in the human body. Forms a hind joint at the knee • Fibula- shorter and smaller bone, giving support to the leg

10. Muscular System • An organ system consisting of skeletal, smooth, and cardiac muscles • It permits movement of the body, maintains posture, and circulates blood throughout the body • Muscle cells (fibers) move by lengthening and contracting, a process that generates much of the body heat needed for survival

12. Muscle • Three Types of Muscle • Skeletal Muscle • Smooth or Visceral Muscle • Cardiac Muscle

13. Skeletal Muscle • Striated voluntary muscles • Attached to bones by dense, fibrous connective tissue called tendons • Important in maintaining posture, providing support and allowing for movement

14. Organization of Skeletal muscle • Muscles are made up of muscle bundles, which subdivide into muscle fascicles • Within each muscle fascicle are units called muscle fiber cells • Within each muscle fiber are contractile fibrils called myofibrils • A single myofibril is subdivided intro sarcomomeres or contractile units

15. Sarcomere • The functional unit in a muscle cell • Inside a sarcomere, there are two protein filaments • Actin: thin filament • Myosin: thick filament • Interaction of both proteins cause muscle contractions

16. Cardiac Muscle • Found in the heart • Its action is beyond conscious control • When the skeletal muscles are exercised, they send signals to the heart via nerve cells to provide more oxygen

17. Smooth Muscle • Found throughout the body (in the walls of blood vessels, the digestive tract, and internal organs) • Involuntary • They respond to demands for increased oxygen from the skeletal muscles by narrowing or widening blood vessels

18. Ligaments • Tendons are tough bands of fibrous connective tissue that usually connect muscle to bone • Ligaments refer to fibrous tissue that connect bones to other bones • Ex: head and neck, wrist, thorax, pelvis, knee

19. How does a muscle contract? • A nerve impulse is sent to a skeletal muscle. • The neuron sending the impulse releases a neurotransmitter onto the muscle cell. • The muscle depolarizes. • Depolarization causes the sarcoplasmic reticulum to release calcium ions. • These calcium ions cause the actin and myosin filaments to slide past each other. • The muscle contracts.

20. Invertebrates • Sponges • Cnidarians • Nematodes • Flatworms • Annelids

21. Hydrostatic Skeleton • Many invertebrates have these skeletons. • As mentioned earlier, three types of skeletons: exoskeleton, endoskeleton, and hydrostatic skeleton.

22. How it Works • Exterior muscles contract along the body of the organism, causing the fluid filled chamber inside to move. • Similar to peristalsis in the human intestine.

23. Nematodes • Locomotion in nematodes Roundworms Important: Nematodes and annelids have a one way digestive track although they are invertebrates

24. Annelids • Earthworms are annelids • Have better locomotion than nematodes because they are segmented, so they can control their peristaltic waves of motion better.