1. The Muscular System
Chapter 6.1

2. Did you know that ?
more than 50% of body weight is muscle !
muscle is made up of proteins and water

3. Fun Facts Question 1:
How many muscles does it take to smile? A: 17 B: 21 C: 32 D: 49

4. Fun Facts Question 2:
How many muscles does it take to frown? A: 13 B: 21 C: 29 D: 42

5. Fun Facts Question 3:
Where is the hardest working muscle located? A: stomach B: eye C: heart D: leg

6. Fun Facts Question 4:
Where is the largest muscle in the body located? A: abdominal region B: arm C: buttock D: leg

7. Info About Muscles Only tissue able to contract
create movement by flexing and extending joints
Contain many mitochondria to create energy (ATP) from sugar during Cellular respiration
When a muscle is fatigued (tired) it is unable to contract because of a lack of oxygen

8. The Muscular System responsible for all movement
three basic types of muscle
Skeletal
Cardiac
Smooth

9. Skeletal Muscle attached by tendons to bones
Voluntary- subject to conscious control
Found in the limbs
Produce movement, maintain posture, generate heat, stabilize joints

10. Smooth Muscle Involuntary- no conscious control
Found mainly in the walls of hollow organs
Peristalsis: alternate contractions that push food through digestive tract

11. Cardiac Muscle Involuntary, rhythmic contractions
Found only in the heart
Heart muscle cells behave as one unit
Heart always contracts to its fullest extent = heart beat

12. How are Muscles Attached to Bone?
always attached to at least 2 points
Origin- attachment to an immovable or less movable bone
Insertion-attachment to a movable bone
When muscles contract, insertion moves towards origin
Origin
Insertion