BIOLOGY CONCEPTS & CONNECTIONS Fourth Edition Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Neil A. Campbell Jane B. Reece Lawrence G. Mitchell Martha R. Taylor From PowerPoint ® Lectures for Biology: Concepts & Connections CHAPTER 30 How Animals Move
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings A colony of leaf-cutter ants can strip a large tree of its foliage in a single night Adults feed on the sap from the trees Young ants eat fungi that grow on the leaves How Do Ants Move Forests?
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Ants carry the leaves to their subterranean nest –Here other workers chew the leaves to cultivate a particular species of fungus for food Over a period of 4-5 years, a colony of leaf-cutters may excavate 50 tons of forest soil (to make nests) and process many tons of forest leaves
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The ant body is a model of strength and mobility made possible by –an exoskeleton made of chitin –three pairs of jointed legs Joints Exoskeletal piece
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Movement is one of the most distinctive features of animals –The nervous system issues commands to the muscular system –The muscular system exerts propulsive force against the skeleton
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Some aquatic animals do not move – Instead they move body parts to generate currents that bring them food –Example: sponges 30.1 Diverse means of animal locomotion have evolved MOVEMENT AND LOCOMOTION
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Locomotion is active travel from place to place –It requires use of energy to overcome forces of friction and gravity –The relative importance of friction and gravity varies depending on the environment
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Swimming –Gravity has little effect on aquatic animals –But friction slows them down A streamlined body shape is an adaptation that aids rapid swimming Figure 30.1A
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings There are several methods of swimming –Using limbs as oars –Expelling water for jet propulsion –Moving tail from side to side –Moving body up and down
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Movement on land –Gravity has a great effect on land animals –But friction has little effect Animals must be able to support themselves against the force of gravity –They must also maintain balance
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Hopping, walking, running, and crawling are methods of movement on land –Legs stabilize the body and propel the animal forward –Muscles generate power for movement –Springy legs store energy for each step or jump Figure 30.1B, C
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Animals that crawl must overcome friction There are two methods of crawling –Side-to-side undulation –Peristalsis (head-to-tail waves of muscle contraction)
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings An earthworm crawls by peristalsis Figure 30.1D 1 Longitudinal muscle relaxed (extended) 2 Circular muscle contracted 3 Bristles Circular muscle relaxed Longitudinal muscle contracted Head
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Flying is the locomotion method of only a few animal groups –Birds, bats, some insects, and extinct reptiles
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Wings must develop enough lift to completely overcome the downward pull of gravity –Lift is generated by the airfoil structure of the wing Figure 30.1E Airfoil
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Skeletons have three major functions –Support –Movement –Protection of internal organs 30.2 Skeletons function in support, movement, and protection SKELETAL SUPPORT
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings There are three main types of skeletons –Hydrostatic skeleton –Exoskeleton –Endoskeleton
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Hydrostatic skeleton –Consists of fluid held under pressure in a closed body compartment –Protects body parts by cushioning them from shock –Provides body shape, which can be changed by contracting muscles in the body wall –Provides support for muscle action –Earthworms, hydras, and jellies have hydrostatic skeletons
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The hydrostatic skeleton of a hydra Figure 30.2A
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Exoskeleton –Rigid external skeleton –It can be hard or leathery
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings –The shells of mollusks are exoskeletons made of calcium carbonate –The exoskeleton of arthropods is made of chitin Figure 30.2B, C Shell (exoskeleton) Mantle
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Endoskeleton –Consists of hard or leathery supporting elements situated among the soft tissues –Most echinoderms, including sea stars and sea urchins, have an endoskeleton of hard plates beneath their skin Figure 30.2D
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings –Vertebrate endoskeletons consist of cartilage or a combination of cartilage and bone Figure 30.2E
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings All vertebrates have an axial skeleton –Supports the axis, or trunk, of the body –Consists of the skull, backbone, and, in most vertebrates, a rib cage Most vertebrates also have an appendicular skeleton –Supports the paired appendages –Consists of bones of the shoulder girdle, upper limbs, pelvic girdle, and lower limbs in humans 30.3 The human skeleton is a unique variation on an ancient theme
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 30.3A
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Movable joints provide flexibility –Three kinds are found in the vertebrate skeleton Figure 30.3C Head of humerus Scapula 1 Ball-and-socket joint Ulna Humerus 2 Hinge joint Ulna Radius 3 Pivot joint
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The human skeleton changed dramatically as upright posture and bipedalism evolved Figure 30.3B Human Baboon
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The human skeleton is versatile, but it is also subject to problems –Lower-back pain –Arthritis –Osteoporosis 30.4 Connection: Skeletal disorders afflict millions
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Bones consist of several kinds of living tissues –A sheet of fibrous connective tissue covers bones –Cartilage at the end of bones cushions joints Bone tissues are served by blood vessels and nerves 30.5 Bones are complex living organs
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings A human humerus Figure 30.5 Cartilage Spongy bone (contains red bone marrow) Compact bone Central cavity Yellow bone marrow Fibrous connective tissue Blood vessels Cartilage
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Bone cells live in a matrix of flexible protein fibers and hard calcium salts –Protein fibers resist cracking –Calcium salts resist compression Long bones –A central cavity contains the yellow marrow that stores fat –Spongy bone contains the red marrow that produces blood cells
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Bones are rigid but not inflexible –If a force is applied that exceeds a bone's capacity, a fracture will result Two factors determine whether a bone will break –The strength of the skeleton –The amount of energy applied to the skeleton 30.6 Connection: Broken bones can heal themselves
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The treatment of broken bones involves two steps The first step is realigning the bone –Sometimes traction must be used to align the broken parts
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The second step is to immobilize the bone –Splint or cast –Plates, rods, and/or screws Figure 30.6A Bone cells then build new bone and repair the break
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Severely injured or diseased bone is beyond repair and must be replaced Several materials can be used in this treatment –Titanium or cobalt alloys –Bone grafts –Synthetic polymers Figure 30.6B
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Muscles pull on bones, which act as levers that produce movement –Tendons connect muscles to bone Antagonistic pairs of muscles produce opposite movements 30.7 The skeleton and muscles interact in movement MUSCLE CONTRACTION AND MOVEMENT
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 30.7 Biceps contracted, triceps relaxed (extended) Triceps Tendon Biceps Triceps Triceps contracted, biceps relaxed Biceps
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Muscles perform work only when contracting A muscle is returned to an extended position by being pulled by other parts of the skeleton
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Skeletal muscle –Attached to the skeleton –Provides body movements –Made up of a hierarchy of smaller and smaller parallel strands 30.8 Each muscle cell has its own contractile apparatus
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 30.8
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Sliding- filament model 30.9 A muscle contracts when thin filaments slide across thick filaments Figure 30.9A Sarcomere Dark band Relaxed muscle Z Z Contracting muscle Fully contracted muscle –Explains the molecular process of muscle contraction
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 30.9B ATP binds to myosin head, which is released from an actin filament Hydrolysis of ATP cocks the myosin head. The myosin head attaches to an actin binding site. The power stroke slides the actin (thin) filament toward the center of the sarcomere. Thick filament (myosin) Thin filament (actin) Myosin head Z line
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Motor neurons carry action potentials that initiate muscle contraction A motor unit consists of a neuron and all the muscle fibers it controls The strength of a muscle contraction depends on the number of motor units activated Motor neurons stimulate muscle contraction
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Spinal cord Motor unit 1 Motor unit 2 Nerve Motor neuron cell body Motor neuron axon Neuromuscular junctions Muscle Tendon Bone Muscle fibers (cells) Nuclei Figure 30.10A
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Activation of the motor units occurs across neuromuscular junctions –A neuron releases the neurotransmitter acetycholine –Acetycholine triggers an action potential in the muscle fiber –Calcium is released from the endoplasmic reticulum –Calcium then initiates muscle contraction
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 30.10B Motor neuron axon Action potential Mitochondrion Tubule Endoplasmic reticulum (ER) Myofibril Plasma membrane Sarcomere Ca 2+ released from ER
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings A balance of aerobic and anaerobic exercise increases strength and endurance Connection: Athletic training increases strength and endurance Figure 30.11
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Body movement is a visible reminder that function emerges from structure An animal's nervous system connects sensations derived from environmental stimuli to responses carried out by its muscles The structure-function theme underlies all the parts and activities of an animal Figure 30.12A, B