Support System: Bones, Joints and Muscles
SEPUP Unit B: Activity 16
FunctionsSkeletal System
(aka Bones)
Support
Movement
Protect internal organs
Make blood cells
Maintain body’s calcium
balance
What are
bones
made of?
Structure of Bones
Living bone cells
surrounded by minerals,
Hard and extremely
strong
Contain channels for blood vessels and nerves
Spongy bone is in the center of
bones.
Spongy bone contains bone
marrow.
Function of bone marro
w?
Bone marrow in long bones makes blood cells
Red Blood cells
White blood cells
Platelets
What are the
different types of bones?
Bone growth?300 bones at birth
Cartilage at birth forms into bone.
Some bones fuse together.
Adults have 206 bones.
Most bones grow until age 20.
Importance of Calcium
Calcium is a
mineral.
• Makes bone hard.• Needed through out
the body.• Bones provide
calcium to the body if there is not enough in your diet.
• Eating dairy and calcium-rich foods is important in youth and adults to prevent osteoporosis.
Muscles Made of muscle cells. Contract and relax. Contraction causes muscles to shorten. Work in pairs.
Do this…. Hold your arm out straight. Feel what the muscles are doing when you bend it
toward your face. Feel the biceps and the triceps muscles.
Tendons Silvery, shiny tissue. Attach muscle to the bone. Tendons attach muscles to bones so that bones
can move.
Types of muscles? Skeletal muscles. Cardiac muscles. Smooth muscles.
Characteristics of Skeletal Muscle?
Attach to bones for movement and to protect inner organs.
Bundles of muscle fibers are surrounded by a connective sheath.
Muscle cells are striated (striped) depending on how much actin and myosin they contain.
Movement of skeletal muscles is voluntary.
Characteristics of Cardiac Muscle?
Found only in the heart. Can beat or pulse on their
own. When cardiac muscle cells
touch each other they beat together.
Has characteristics of Smooth and Skeletal muscle.o Are involuntary (like smooth
muscle).o Striated like skeletal muscle.
Characteristics of Smooth Muscle?
Found in the walls of hollow organs like the digestive tract and walls of blood vessels.
Cells are thin and long. They form sheets rather than
bundles. Control slow, involuntary movement.
Examples of Smooth Muscle Movements?
Contraction of the walls of the stomach and intestines.
Contraction of arteries to regulate the blood pressure and the flow of blood.
Smooth Muscle
Cardiac Muscle
Skeletal Muscle
Voluntary and Involuntary Movements?
Voluntary – Actions that are under your control. Involuntary – Actions that are not under your
control.
Voluntary: Actions that are under your control.
Skeletal muscles – walking, talking, bending.
Involuntary: Actions that are not under your control.
Smooth and Cardiac muscles – breathing, digesting, heart beating.
http://vimeo.com/8321006
Joints and Ligaments Joint - Place where two bones meet. Ligaments connect one bone to another bone. Ligaments stabilize the joint and allow it to move.
Types of Joint
s
How do muscles, joints and bones work?
The skeletal/muscle system works like a lever.