Support and Locomotion
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.
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
Plants are not
Do not move
Attached to stationary object
Easier to get food
Find suitable places to live
Ability to move away from harmful environments
Find mates and reproduce
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.
Single celled, protists
Multicellular specialized tissues
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
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
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 its base
Moves quick by somersaulting its base over its tentacles
Inches along, bending over and attaching its tentacles to an object
Floats upside down in water, creates air bubble in its 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
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
Walk, jump, and fly
3 body sections
Head, thorax, abdomen
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:
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
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 ?
Bone connective tissue, hard and inflexible, made of living cells
Sites for muscle attachments
Gives body general shape
Brain, spinal cord, heart, lungs
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
Is a connective tissue
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
Skull cranium, facial and jaw bones
Spinal column backbone
33 bones called vertebrae
Sternum - breastbone
Arms and leg bones
Clavicle collar bone
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.
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
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.
Walls of digestive organs
Walls of arteries and veins
Other internal organs
Long and overlap to form sheets
Section Review Quiz:
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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