1. OBJ: Given video, notes, activity sheet SWBAT describe three types of muscle tissue and explain why muscles work in pairs with 70% accuracy. BRING IN TEXTBOOK DN: HW check- Skeletal System Booklet; Video: Muscular System ACT: Introduction to Muscular System Text, Read 24-28, Work on Muscular System Booklet HW: Complete Muscular System Booklet; Work on SMSD Review Sheets; SMSD Exam, Feb 25; Winter Break: NYSSAE 2008 Exam (on scantron, due Feb 23).

2. MUSCLE NOTES Conscious = self awareness; “I think, therefore I am” Unconscious = not aware Involuntary Muscles: not under concious control; example: heart beat, breathing, digesting food Voluntary Muscles: under concious control; example: facial expressions, walking Striated = muscle with lines Nonstriated = muscles without lines

3. Skeleton Heart Organ

4. THREE TYPES OF MUSCLES Skeletal Muscles: attached to and moves bones of the skeleton Striated muscle Voluntary muscle Quick, fast but tires quickly Tendon: attached muscle to bone

6. THREE TYPES OF MUSCLES Cardiac Muscle: heart only striated muscle involuntary muscle does not tire Smooth Muscle: part of internal organs and blood vessels. not striated involuntary muscle moves slowly, tires more slowly

7. MUSCLES WORK IN PAIRS Muscles work in pairs because... Muscle cells can only contract (they can not extend or expand). One muscle contracts, the other muscle relaxes (see transparancy)

8. Muscles contract only!!!