Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings PowerPoint Lectures for Biology: Concepts and Connections, Fifth Edition – Campbell, Reece, Taylor, and Simon Lectures by Chris Romero Chapter 30 How Animals Move

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Elephants Do the "Groucho Gait" Movement is one of the most distinctive features of animals, from elephants to Groucho Movement is dependent on precise interaction among three organ systems – Nervous system issues commands to muscular system – Muscular system exerts force that makes the animal move – Skeletal system provides the firm structure that muscular force works against

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings MOVEMENT AND LOCOMOTION 30.1 Diverse means of animal locomotion have evolved Locomotion: active travel from place to place – Animal must use energy to overcome friction and gravity Swimming – Water supports against gravity but offers frictional resistance – Different body structures are used to swim – A streamlined body aids rapid swimming

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Locomotion on Land: Hopping, Walking, Running, and Crawling – Animals that hop, run, or walk must expend energy to propel themselves and stay upright – Burrowing or crawling animals must overcome friction May move by side-to-side undulation or by peristalsis

LE 30-1d Longitudinal muscle relaxed (extended) Circular muscle contracted Circular muscle relaxed Bristles Head Longitudinal muscle contracted

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Flying – The wings of birds, bats, and flying insects are airfoils Shape alters air currents Pressure differences create lift At the cellular level, all animal movement has similarities – Based on contractions of microtubules or microfilaments

LE 30-1e Airfoil

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Video: Clownfish and Anemone Video: Clownfish and Anemone Video: Flapping Geese Video: Flapping Geese Video: Soaring Hawk Video: Soaring Hawk Video: Swans Taking Flight Video: Swans Taking Flight

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings SKELETAL SUPPORT 30.2 Skeletons function in support, movement, and protection A skeleton has many functions – Body support – Movement as muscles act against it – Protection of internal organs

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Hydrostatic skeleton – Consists of fluid held under pressure in a closed body compartment – Works well for aquatic animals and those that burrow by peristalsis Most are soft and flexible (example: hydra) Video: Hydra Eating Daphnia Video: Hydra Eating Daphnia

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Exoskeleton – Rigid, external covering with muscles attached at inner surface – Arthropod chitin exoskeleton Thin and flexible at joints Secreted by living cells Must be molted periodically, leaving the animal unprotected – Mollusc calcium carbonate exoskeleton Enlarges by adding to outer edge

LE 30-2c Mantle Shell (exoskeleton)

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Endoskeleton – Hard or leathery supporting elements situated among the soft tissues – Vertebrate skeleton consists of cartilage or combination of cartilage and bone

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 30.3 The human skeleton is a unique variation on an ancient theme Skeletons of vertebrates have a number of similarities – Axial skeleton Skull, vertebrae, and ribs – Appendicular skeleton in most Shoulder girdle, upper limbs, pelvic girdle, lower limbs

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The human skeleton reflects bipedal evolution – Skull is large, flat-faced, balanced on top of backbone – Backbone is S-shaped – Pelvic girdle is shorter, rounder, and oriented vertically – Bones of hands and feet are adapted for different functions Hands: grasping and manipulating Feet: support the entire body bipedally

LE 30-3a Skull Examples of joints Shoulder girdle Clavicle Scapula Sternum Ribs Humerus Vertebra Radius Ulna Pelvic girdle Carpals Phalanges Metacarpals Femur Patella Tibia Fibula Tarsals Metatarsals Phalanges

LE 30-3b Baboon (quadrupedal) Human (bipedal)

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The versatility of the vertebrate skeleton comes in part from its movable joints – Ball-and-socket joints allow movement in all directions – Hinge joints permit movement in one plane – Pivot joints allow bones to rotate

LE 30-3c Ball-and-socket joint Hinge joint Ulna HumerusHead of humerus Scapula Ulna Pivot joint Radius

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 30.4 Bones are complex living organs Bones consist of several kinds of moist, living tissue – Fibrous connective tissue covers the outer surface – Cartilage cushions the joints – Bone cells live in a matrix of flexible collagen fibers embedded in hard calcium and phosphate

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Long bones have a central cavity – Stores yellow bone marrow, which is mostly stored fat Spongy bone is at the ends of long bones – Contains red marrow, which produces blood cells Blood vessels and nerves coursing through channels service bone cells

LE 30-4 Cartilage Spongy bone (contains red bone marrow) Compact bone Central cavity Yellow bone marrow Fibrous connective tissue Blood vessels Cartilage

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings CONNECTION 30.5 Broken bones can heal themselves Two factors determine whether a bone might break – Strength of skeleton – Angle and amount of force applied Bone cells can build new bone and heal a break, given the opportunity – Realignment; splint or cast; traction Severely injured or diseased bone must be replaced

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings CONNECTION 30.6 Weak, brittle bones are a serious health problem, even in young people Osteoporosis is a bone disease characterized by low bone mass and structural degeneration of the bone matrix Lowered estrogen production makes this a problem among older women Unhealthy lifestyles have made osteoporosis a serious concern for young people

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings MUSCLE CONTRACTION AND MOVEMENT 30.7 The skeleton and muscles interact in movement Muscles are connected to bones by tendons Antagonistic pairs of muscles produce movement – A muscle can only contract – To extend, a muscle must be pulled by the contraction of an opposing muscle

LE 30-7 Biceps contracted, triceps relaxed (extended) Biceps Triceps Tendon Triceps Biceps Triceps contracted, biceps relaxed

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 30.8 Each muscle cell has its own contractile apparatus A muscle consists of bundles of parallel muscle fibers Each muscle fiber is a bundle of smaller myofibrils – A single cell with many nuclei Each myofibril consists of repeating units called sarcomeres A sarcomere, composed of overlapping thick myosin and thin actin filaments, is the muscle's contractile apparatus

LE 30-8 Muscle Bundle of muscle fibers Single muscle fiber (cell) Nuclei Myofibril Light band Dark band Light band Z line Sarcomere TEM 26,000  Light band Light band Dark band Z line Sarcomere Z line Thick filaments (myosin) Thin filaments (actin) Video: Sliding Filament Theory

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 30.9 A muscle contracts when thin filaments slide across thick filaments The sliding-filament model of muscle contraction – A sarcomere contracts when its thin filaments slide across its thick filament – Contraction is caused by energy-consuming interactions of myosin and actin molecules

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings – The sequence of detach-extend-attach-pull occurs repeatedly ATP binds to a myosin head, which is released from an actin filament Hydrolysis of ATP extends 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

LE 30-9b-4 Thin filament (actin) Z line ATP Myosin head ATP binds to a myosin head, which is released from an actin filament. The myosin head attaches to an actin binding site. ADP P Thick filament (myosin) Hydrolysis of ATP extends the myosin head. P ADP ADP  P New position of Z line The power stroke slides the actin (thin) filament toward the center of the sarcomere.

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Motor neurons stimulate muscle contraction A motor unit consists of a motor neuron and the muscle fibers it controls A motor neuron can stimulate more than one muscle fiber because of its many branches – Neuron's axons form neuromuscular junctions with muscle fibers – Action potential from neuron triggers release of acetylcholine

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings – Acetylcholine diffuses across neuromuscular junctions to muscle fibers – Change in fiber membrane permeability triggers action potentials that pass into the center of the muscle cell – Calcium released from the endoplasmic reticulum initiates filament sliding and muscle contraction

LE 30-10a Spinal cord Motor unit 1 Motor unit 2 Motor neuron cell body Nerve Motor neuron axon Nuclei Muscle fibers (cells) Neuromuscular junctions Muscle Tendon Bone

LE 30-10b Tubule Endoplasmic reticulum (ER) Myofibril Plasma membrane Motor neuron axon Action potential Mitochondrion Sarcomere Ca 2  released from ER

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings CONNECTION Athletic training increases strength and endurance Aerobic and anaerobic exercise must be balanced Aerobic exercise increases efficiency and fatigue resistance of muscles – Increases blood flow and mitochondria size – Strengthens heart and circulatory system

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Anaerobic exercise builds larger muscles that generate greater power – Increases size of muscle fibers – More glycogen stored as fuel reserve

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The structure-function theme underlies all the parts and activities of an animal Animal movement is a visible reminder that function emerges from structure – Integrates the sensory, nervous, and motor systems Athletic ability results from adaptations that have been refined through natural selection and contribute to our survival as a species