1. Homework #3 is due now.
Bonus #3 is due F 4/27.

2. Nervous System Signaling
Stimulus
Integration
Transduction
Transmission
Response

3. Muscles allow movement

4. An earthworm: without something to push against, muscles are not much use.
CB 49.25

5. The skeleton, made of bones, gives support
CB 49.26

6. Bones are alive

7. Connections between bones and muscles

8. Muscles can only contract
Muscles can only contract. Therefore, two muscles are needed for each range of motion.
CB 49.27

9. 2 nerve signals for every movement: excitatory and inhibitory
CB 49.27

10. How do muscles contract?

11. Muscle cells are comprised of series of sarcomeres.
CB 49.28

12. Muscle cells are comprised of series of sarcomeres
CB 49.32

13. Each sarcomere is a repeating unit of actin and myosin proteins
CB 49.28

14. As each sarcomere contracts, the muscle contracts
CB 49.28

15. Neuro-transmitters released at nerve/
muscle junction cause calcium to be released in muscle
CB 49.32

16. A third protein, tropomyosin controls when the muscle contracts
CB 49.31

17. ATP provides the energy for myosin movement along the actin
CB 49.30

18. CB 49.32

19. How do muscles contract?
(if you have a strong stomach, this video shows muscle contraction using a naked man and a cadaver)