1. Each motion had a limited range of movement
Each motion had a limited range of movement. The types and ranges of movement differed.
Different joints allow rotational movements, angular movements, and gliding movements.

2. Chapter 10: Movement and Forces
10.1 The skeletal system provides movement and protection
10.2 The muscular system makes movement possible
10.3 Muscles exert forces
10.4 Bones and joints at as levers

3. d e b Match each definition with the terms.
1. a bony structure that allows rotation
2. the skeleton division containing the skull
3. the part of a bone that produces red blood cells
a. compact bone d. ball-and-socket joint
b. axial skeleton e. marrow
c. immovable joint d b e

4. Muscles perform important functions
Beating heart, moving food through your digestive system, blinking eyes
Some movements are automatic, some you control
Muscles help
Produce movement
regulate your body’s temperature (keep it stable)
maintain your body’s posture

5. Movement
Muscular system – consists of skeletal muscles (attached to the skeleton)
Most skeletal muscles are attached to bones by tendons
Made of muscle fibers (many muscle cells)
Contract – shorten / relax – lengthen
Most muscles work in coordinate groups
Bend arm and release: biceps/triceps coordination

6. Maintaining Body Temperature
Homeostasis: the balance of conditions in the body
A muscle contracts  releases heat
Shiver: quick muscle contractions release heat to warm your body

7. Maintaining Posture
Gravity is pulling your body down, but most muscles are always a little bit contracted
Called tension, or muscle tone
This is present even when sleeping!
Muscles make contracting and relaxing adjustments to keep you sitting or standing
These are automatic

8. Types of Muscles All contract and relax Perform different functions
Skeletal
attached to the skeleton
under voluntary control.
Smooth
located in walls of some organs
under involuntary control
Cardiac
located in the walls of the heart

9. Skeletal Muscles Attached to bones Help give the body its shape
Voluntary/controlled movement ~ “voluntary muscles”
Long fibers made of many bundles made of many cells
Cells can have more than one nucleus
Slow twitch – move slow but can sustain tension for longer periods
Fast twitch – move quick but can only sustain tension for shorter periods

10. Smooth Muscles Involuntary muscle Contracts slowly
Walls of stomach and intestines
helps push food through the digestive system
Also found in blood vessels
helps regulate blood pressure

11. Cardiac Muscles Involuntary muscle Only found in the heart
Each cardiac muscle cell is branched
cells connect in a chain
The chains form webs and layers that allow cardiac muscle cells to contract together and make the heart beat

12. Checking in… What do the bundles that make up skeletal muscle do?
One type allows muscles to move slowly and maintain tension for a long time. Another allows muscles to move more quickly and sustain tension for a shorter period.
Why are skeletal muscles called voluntary muscles?
They move when you want them to.
Compare and contrast the three types of muscle: skeletal, smooth, and cardiac.
Skeletal muscles give the body shape and control movement. They are voluntary muscles. Smooth muscles contract without voluntary control. They are found in the walls of the stomach, intestines, and blood vessels. Cardiac muscle moves without conscious control and is found only in the heart.

13. Skeletal muscles, tendons, and joints allow bones to move
Many skeletal muscles are attached to your bones by tendons
Tendons: strong connective tissue
Muscle contracts and shorten  pull the tendon  tendons pulls on the bone to make it move
How do muscles move bones?
Muscles can only contract or
relax. By contracting, they pull on the tendons.

14. Movement Muscles must work together in coordinated groups
Muscle groups produce movement in opposite directions
A muscle contracts and shortens – it exerts a force
Counterpart relaxes
Which muscles work together to bend and extend your leg?

15. Muscular system + skeletal system + BRAIN!
Movement
Lift your leg without bending your knee
Which muscles must contract in order to keep your knee from bending?
What if you point your toes?
Some of the muscles in your leg are working to stabilize the joints
Other muscles are contracting to produce the controlled movement
Muscular system + skeletal system + BRAIN!

16. Muscles grow and heal
Baby neck muscles not strong enough to hold up head
Childhood/adolescence: develop muscular coordination and become more graceful in their movements
Exercise: muscles may get big
# muscle fibers does NOT increase
thickness of the muscle fibers and surrounding tissues increases
Muscles can become sore during or after exercise:
During exercise the muscle cells may not receive enough oxygen for cellular respiration  switch to fermentation for energy
Fermentation causes the buildup of lactic acid in muscles
 cramps or aches
Muscles can also be damaged (overstretched or torn)