Chapter 30- How Animals Move Aerobic exercise Anaerobic exercise Appendicular skeleton Axial skeleton Ball-and-socket joint Endoskeleton Exoskeleton Hinge joint Hydrostatic skeleton Ligaments Locomotion Motor units Myofibrils Neuromuscular junctions Osteoporosis Pivot joint Red bone marrow Sarcomeres Skeletal muscle Sliding-filament model Tendons Thick filament Thin filament Yellow bone marrow

Locomotion Movement from 1 place to another –Requires E to overcome friction and gravity –All ways animals move have similarities but have adapted to an environment

Types of skeletons Exoskeleton- rigid external skeleton –Muscles attach to inner surface, move jointed body parts –Insects, arthropods

Types of skeletons Hydrostatic skeleton- fluid under pressure in closed body compartment –Earthworms, jellies –Protects (cushions body parts from shock)

Types of skeletons Endoskeleton- hard/leathery supportive elements inside body

Human skeleton Axial- supports trunk- skull, backbone, ribs Appendicular- supports appendages Bipedal vs. quadrapedal: –2-legged vs. 4-legged walking

Joints Ball and socket- enables movement in several planes Hinge- permits movement in single plane Pivot- enables rotation

Skeletal disorders Arthritis- inflammation of joints –Rheumatoid- autoimmune disease Osteoporosis- bones become thinner, porous and easily broken –Many contributing factors, there is treatment and prevention

Bones Made of CT, cartilage and bone matrix Bone matrix- flexible protein collagen embedded in hard Ca salts Shaft- compact bone Ends of bone- spongy bone Yellow bone marrow- stored fat brought into bone by blood Red bone marrow- produces blood cells Haversian canals- where blood vessels run, transport nutrients and wastes and hormones Can absorb force up to certain extent, then break Interact with muscles to perform movement –Tendons- connect muscle to bone –Muscles are antagonistic- pairs that work opposite each other to produce movement by contraction and relaxation

Skeletal muscle Consists of bundles of fibers- each fiber being a single cell with many nuclei Each fiber is many myofibrils consisting of repeating units- sarcomeres Sarcomeres- contractile mechanism in a myofibril –Z line to Z line – each is made up of an actin (thin) and a myosin (thick) filament Thin filament sliding across the thick filament is a sarcomere contraction Contraction is an E consuming interaction between actin and myosin Stimulated by contact with motor neurons –1 neuron can stimulate many fibers b/c a motor unit controls a few fibers –Axons release acetylcholine-which diffuses into muscle fiber making them contract –More neurons controlling a fiber = stronger contraction –Eye- 1 neuron/fiber (for precision)

Aerobic vs. Anaerobic exercise Aerobic exercise- increases efficiency and fatigue resistance of muscles –Endurance sports- increases size and # of mitochondria Anaerobic exercise- building larger muscles that generate greater power –Increases size of muscle fibers Cross-training = both Movement- structure allows function