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Support and Locomotion

Chapter 13

Key Concepts

Describe the different methods of locomotion in simple organisms.

Describe the roles of bones and muscles in human locomotion.

Relate the structures of a chicken wing to their functions.

Key Words





Skeletal muscle





Section Objectives

List the advantages of locomotion

Compare exoskeletons and endoskeletons.

Describe methods of locomotion in the protist, hydra, earthworm, and grasshopper.

The Advantages of Locomotion

Define locomotion - move from one place to another


Animals are

Plants are not


Do not move

Attached to stationary object

Corals, barnacles


Easier to get food

Find suitable places to live

Ability to move away from harmful environments

Escape enemies

Seek shelter

Find mates and reproduce

Artic Tern

Some animals move great distances to find suitable places to live. Artic terns fly more than 16,000 km between their nesting grounds in the Arctic and Antarctic.

Different Methods

Single – celled, protists


Multicellular – specialized tissues

Contractile proteins

Change in length

Muscles and Skeletons

Muscles can exert force when they contract or shorten

Exoskeleton: site of attachment for muscles

Jointed for easy movement

Protection for internal structures

Can not grow

Shed, molt

Soft body unprotected

New larger ones

Mollusks: Clams, oyster

Shells made of Ca compounds

Chitin: tough, lightweight, carbohydrate materials


All can grow





Muscle movement possible

Fish, amphibians, reptiles, birds, mammals

Locomotion in Protists

Usually move by

Pseudopods – temporary projections

Move when cytoplasm flows


Ameboid movement



Cilia – thousands of short, hairlike, rhythmic, oarlike beating moves organism through water

Flagella – like cilia, but longer usually one or two per cell

Locomotion in the Hydra

Specialized cells for contraction

Mucus-secreting cells and Ameboid cells

Allows gliding along it’s base

Moves quick by somersaulting it’s base over it’s tentacles

Inches along, bending over and attaching it’s tentacles to an object

Floats upside down in water, creates air bubble in it’s base

Locomotion in the Earthworm

Muscles to burrow through soil

Outer layer – circles worm

Contract, worm gets longer and thinner

Inner layer – longitudinal, goes length of body

Contract, worm gets shorter and thicker

Fluid in worm stiffens and now can move through soil

Four pairs of bristles called " Setae "

Rear anchor then relax, front anchor then relax

Earthworm Muscles

Both circular and longitudinal muscle layers can be seen in this cross section of an earthworm. When the outer layer of circular muscles contracts, the worm lengthens and becomes thinner. When the inner layer of longitudinal muscles contracts, the worm becomes shorter and thicker.

Locomotion in the Grasshopper




Flexible joints

Walk, jump, and fly

3 body sections

Head, thorax, abdomen

Jointed legs

First two airs for walking

Hind pair for jumping

20 x body length

Outer pair of wings protect inner pair that are used for flying

Muscles attached to thorax

No direct connection to wing

Wings move by changing shape of body wall of thorax

Muscles work in pairs

Section Review Quiz:
put all answers on loose-leaf )

1. What is locomotion?

2. What is an exoskeleton? An endoskeleton?

3. Name some means used by protists for locomotion.

4. Name the two layers of muscles used in locomotion in the earthworm.

The Human Musculoskeletal System

Section Objectives:

Describe the functions and structure of the bones and cartilage found in the human musculoskeletal system.

Name the major parts of the human skeleton and the types of joints found in it.

Describe the structure of skeletal muscle and explain how voluntary movement is accomplished.

Compare skeletal muscle with smooth muscle.

Biology and YOU

Q: Do people shrink as they grow older ?


Lose minerals



Drink MILK


Bone – connective tissue, hard and inflexible, made of living cells

Sites for muscle attachments


Gives body general shape



Brain, spinal cord, heart, lungs

Storage minerals



Place where red blood cells and some white blood cells are produced

Collagen – basic part

protein material with great strength

Osteoblasts – secret collagen ( forms fibers ) and poysaccharides ( cement )

Osteocytes – bones cells that are formed when osteoblasts are trap in small cavities in the bone

Haversian canal – center of series of small circles of osteocytes

Blood vessels and nerves

Nutrients, oxygen and waste removal


Makes new bone cells fro growth and repair

Tough membrane covering outside of bone

Point at which muscles attach to bone

Two types of bony tissue
( made of same material


Very dense


Contains marrow


More porous

Contains marrow


Is a connective tissue

Bends easy

Slowly changes to bone as child grows


Found – end of ribs, joints, nose, outer ear

Gives support and allows some bending

Cushion against impact and pressure


As the embryo develops, minerals are laid down, and much of the cartilage slowly changes into bone.

This process goes on into adulthood.

The Human Skeleton

Adult - 206 bones

Axial skeleton

Skull – cranium, facial and jaw bones

Spinal column – backbone

33 bones called vertebrae


Sternum - breastbone

Appendicular skeleton

Arms and leg bones

Pectoral girdle

scapula – shoulder

Clavicle – collar bone

Pelvic girdle

Hip bones


Several types

Immovable - cranium

Hinge - knee

Ball-and-socket - shoulder

Pivot - neck

Gliding - wrist


Bones are held together by tough fibrous bands of connective tissues

Synovial fluid is secreted into joints to keep them lubricated and reduces friction at the joint, between the bones.

Skeletal Muscle
( striated )

Used in locomotion and voluntary movement

Made up of individual muscle fibers

Bundles bound by connective tissue

Striped or striated under microscope

Alternating light and dark bands

Myofibrils bundle of smaller fibers

Still finer protein filaments

One thick – myosin

One thin – actin

They overlapping pattern , making muscle look striped

Sliding filament theory

Muscle contraction

Muscles shorten when actin slides over myosin

As overlap increases, the fibers shorten

ATP supplies energy

Cross bridges between actin and myosin allows fibers to exert a pull.

Mitochondria produces ATP

Voluntary Muscle Movement

Starts and continues by impulses from the brain and spinal cord.

Action that is under conscious control.

Throwing a ball

Needs actions of skeletal muscles


Muscles are attached to bone by strong fibers of connective tissues.

Attached in such a way that they pull on the bones.

This movement allows bones to act as levers.

Several muscles are around each joint that pull in different directions

Working in Pairs

Muscles work in antagonistic pairs

One contracts, the other relaxes

Biceps and triceps


Extensors and flexors

Muscle tone – keeps body ready for the powerful contractions of movement.

Maintains posture of back and neck partly contracted.

Smooth Muscle

Involuntary control


Walls of digestive organs

Walls of arteries and veins


Other internal organs

Long and overlap to form sheets

Section Review Quiz:
( put all answers on loose-leaf )

1. What is the difference between bone and cartilage?

2. Name the two main parts of the skeleton.

3. What is a joint?

4. What are the three types of muscles in the human body?


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