1. The muscular system makes movement possible.
The human body is made up of systems that work together to perform necessary functions.

2. Muscles are involved in every movement of the body.
Muscles are made of individual cells called muscle fibers.
Muscles perform important functions.
Each muscle fiber or strand can contract or stretch.
Muscles allow your body to move, to generate heat, and to maintain posture.

3. The muscular system works with the skeletal system to allow movement.
Individual cells, called muscle fibers, contract and relax.
Muscles are attached to bone by stretchy connective tissue, and, working in pairs, they contract and relax to move the body.

4. Muscles assist in homeostasis by functioning to maintain body temperature.
When muscles contract they release heat, so the quick muscle contractions that occur when you shiver release heat and raise your body temperature.

5. Muscles make constant, automatic, tiny adjustments to keep you sitting or standing upright.
The muscles that maintain posture are only completely relaxed when you are unconscious.

6. The body has three types of muscles.
Skeletal muscles are attached to the skeleton.
Smooth muscle are found inside certain organs
Cardiac muscle is found in the heart.

7. attached to the skeleton Characteristics: Perform voluntary movement
Definition:
attached to the skeleton
Characteristics:
Perform voluntary movement
Skeletal Muscles
Example:
Leg muscles
Nonexample:
Heart muscles

8. Muscles that move when you want them to.
Definition:
Muscles that move when you want them to.
Characteristics:
Made of long fibers
Voluntary Muscles
Example:
Leg muscles
Nonexample:
Smooth muscle

9. Smooth Muscles
Smooth muscles are the muscles that perform automatic movement inside the intestines and the stomach.
Smooth muscles are involuntary, while skeletal muscles are not.
Smooth muscles are found in organs while skeletal muscles are attached to the skeleton.

10. Muscle the heart is made of. Characteristics: Has a branched shape
Definition:
Muscle the heart is made of.
Characteristics:
Has a branched shape
Cardiac Muscle
Example:
The muscle cells in the heart
Nonexamples:
Stomach muscles

11. Skeletal muscles and tendons allow bones to move.
The tendon is the link between the muscle and the bone. When a muscle contracts, it pulls on the tendon, which pulls the bone.

12. During early childhood muscles are not yet well developed.
As humans grow older, muscles develop and become more coordinated.
Muscles grow and heal.
Regular exercise increases muscle size.
Sore muscles indicate damaged muscle fibers.