3. Endoskeleton
• Skeleton is located
within the body
Exoskeleton
• Skeleton is located
outside
Hydroskeleton
• Fluid-filled, under
pressure
• The pressure of the
fluid and action of
the surrounding
circular and
longitudinal
muscles are used to
change an
organism's shape
and produce
movement
9. Bone Formation: Ossification
Osteoblast –bone building cells
-secret protein and collagen which form strong fibers of bones
Osteoclast –Large multinucleated cells that secrete enzymes that digests the
bones, so the osteoblast remodel the bone as needed
12. Types of muscles
Smooth
-propels food
through the
food tube and
provide
tension in the
urinary bladder
Cardiac
-found only in
the heart
Skeletal
-Enables
voluntary
movement of
bones
15. Muscle Fiber Structure
Sarcoplasm = cytoplasm of the muscle fiber
Sarcolemma = plasma membrane
Myofibrils = threadlike structures running lengthwise
through the muscle fiber, composed of even
smaller structures called myofilaments
Sarcomere = contractile unit of a myofibril, consisting of
overlapping actin and myosin filaments
16. Muscle Contraction occurs when
actin and myosin filaments slide
past each other
The sliding filament theory
18. Muscles work in pairs
Examples: Biceps and Triceps
Agonist – muscle that contracts to produce a particular
action
Antagonist – muscle that produce the opposite
movement
19. White and Red muscle fibers
White = Fast response
Red = slow, enduring activities
Example: Chicken’s legs have red fibers while
its breast have white fibers
20. Fast twitch vs Slow twitch
Fast twitch = moderate, enduring activities
Slow twitch = long, slow response
