The Muscular System Chapter 6.1

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

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

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

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

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

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

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

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

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

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

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