2. Regents Biology 2007-2008 Skeletons & Muscles

3. Regents Biology Animal Movement What are the advantages of being mobile? mobilesessile

4. Regents Biology Lots of ways to get around…

5. Regents Biology Lots of ways to get around… molluskmammal birdreptile

6. Regents Biology Lots of ways to get around… birdinsect mammalbird

7. Regents Biology Muscle voluntary involuntary, contract on their own involuntary evolved first

8. Regents Biology tendon skeletal muscle muscle fiber (cell) protein fibers bundles of protein fibers Organization of Skeletal muscle

9. Regents Biology Human endoskeleton 206 bones ball & socket hinge pivot

10. Regents Biology Muscles movement  Muscles do work by contracting  skeletal muscles come in antagonistic pairs  flexor vs. extensor  contracting = shortening  move skeletal parts  tendons  connect bone to muscle  ligaments  connect bone to bone

11. Regents Biology

12. The Trigger: motor nerves  Motor nerves trigger muscle contraction

13. Regents Biology Fast twitch & slow twitch muscles  Slow twitch muscle fibers  contract slowly, but keep going for a long time  more mitochondria for aerobic respiration  long distance runner  “dark” meat = more blood vessels  Fast twitch muscle fibers  contract quickly, but get tired rapidly  sprinter  “white” meat

14. Regents Biology Muscle limits  Muscle fatigue  lack of sugar  lack of ATP  low O 2  lactic acid lowers pH which interferes with protein function  nerve fatigue  loss of chemical transmitter  Muscle cramps  build up of lactic acid  lack of energy (ATP)  ion imbalance  massage or stretching increases circulation

15. Regents Biology Diseases of Muscle tissue  ALS  amyotrophic lateral sclerosis  Lou Gehrig’s disease  motor neurons degenerate  Myasthenia gravis  auto-immune  antibodies to nerve transmitter chemical Stephen Hawking

16. Regents Biology Botox  Bacteria Clostridium botulinum toxin  blocks release of nerve transmitter  but botulism can be fatal! muscle