Sensory and Motor Mechanisms

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Arthropod exoskeletons are made of cuticle and can be both strong and flexible.

The polysaccharide chitin is often found in arthropod cuticle.

Slide 79

Endoskeletons

An endoskeleton consists of hard supporting elements, such as bones, buried in soft tissue

Endoskeletons are found in sponges, echinoderms, and chordates.

A mammalian skeleton has more than 200 bones.

Some bones are fused; others are connected at joints by ligaments that allow freedom of movement.

Slide 80

Bones and joints of the human skeleton

Examples of joints

Humerus

Ball-and-socket joint

Radius

Scapula

Head of humerus

Ulna

Hinge joint

Ulna

Pivot joint

Skull

Shoulder girdle

Rib

Sternum

Clavicle

Scapula

Vertebra

Humerus

Phalanges

Radius

Pelvic girdle

Ulna

Carpals

Metacarpals

Femur

Patella

Tibia

Fibula

Tarsals Metatarsals Phalanges

1

1

2

3

3

2

Slide 81

Types of Locomotion

Most animals are capable of locomotion, or active travel from place to place.

In locomotion, energy is expended to overcome friction and gravity.

In water, friction is a bigger problem than gravity. Fast swimmers usually have a streamlined shape to minimize friction.

Slide 82

Locomotion on Land

Walking, running, hopping, or crawling on land requires an animal to support itself and move against gravity.

Diverse adaptations for locomotion on land have evolved in vertebrates.

Slide 83

Energy-efficient locomotion on land

Slide 84

Flying

Flight requires that wings develop enough lift to overcome the downward force of gravity.

Many flying animals have adaptations that reduce body mass.

For example, birds lack teeth and a urinary bladder

Slide 85

What are the energy costs of locomotion?

Body mass (g)

Running

Swimming

Flying

Energy cost (cal/kg•m)

102

103

10

1

10–1

10–3

106

1

RESULTS

Slide 86

You should now be able to:

Distinguish between the following pairs of terms: sensation and perception; sensory transduction and receptor potential; tastants and odorants; rod and cone cells; oxidative and glycolytic muscle fibers; slow-twitch and fast-twitch muscle fibers; endoskeleton and exoskeleton.