Download The Skeletal and Muscular Systems

The Skeletal and Muscular
Systems
Structures of the Body
• cells: the building blocks of life
– make up your body
– many types of cells
• bone cells, muscle cells, blood cells, and nerve cells
• tissue: cells of the same type working
together
– bone cells make bone tissue/muscle cells make
up muscle tissue
• organs: body parts that do special jobs
– tissues of different kinds work together in organs
• bone tissue and other tissue form organs of bones
• muscle tissue and other tissue form organs of muscles
• systems: groups of organs working
together
– bones (type of organ) work together to make
the skeletal system
– muscles (type of organ) work together to
make the muscular system
The Skeletal System
• your body is made up of many
bones
– bones support your body and give
it shape
– help you move and protect the
organs inside your body
– bones meet at joints
– some open and close like hinge of
a door
• your knee
– other joints let a bone move in
many directions
• your shoulder
The Muscular System
• body has 3 types of muscles
– skeletal muscles
•
•
•
•
move head, arms, legs, fingers, toes
can’t push, only pull
work in pairs
control skeletal muscles by thinking
– cardiac muscles
• muscle your heart is made of
• muscle works without your thinking about it
– smooth muscles
• help organs inside your body do their job
• muscle works without your thinking about it
• all muscles move parts of your body
• do this by getting longer and shorter
A Closer Look at Muscles
• striated muscles
– skeletal muscle with light and dark stripes
• stripes patterns made by working parts of muscle
cell
– fibers in skeletal muscle can be up to 30 cm
(12in) long
– some muscles have more than 2000 fibers
packed together
• smooth muscle
– does not have stripes
– found in walls of organs
• stomach,intestines, blood vessels, bladder
– work by squeezing and relaxing slowly and smoothly
– fibers are shorter than skeletal muscles
• cardiac muscle
–
–
–
–
stripes but not as many as skeletal (striated)
makes up walls of heart
squeezes and relaxes without ever stopping
never gets tired
Summary
• the body is made up of basic parts called
cells
– cells make up tissues
– tissues make up organs
– organs make up systems
• skeletal and muscular systems work
together to help the body move