1. Sliding Filament Theory

2. Muscle breakdown anatomy
Epimysium: Covers entire muscle, made of thousands of muscle cells
Perimysium: surrounds the fascicle
Fascicle: Muscle fiber groups, about 150 fibers
Muscle Fibers: long, cylindrical cells about the size of hair
Endomysium: Surrounds individual muscle fiber
Myofibril: within each fascicle, contains thousands cells, makes muscle contraction

3. Review: Talk about each part with a neighbor

4. More muscle fiber break down
Sarcomere: contractile element. Bands of myofibrils aligned.

5. Sarcomere break down Myofilaments:
Thick = contain bundled myosin molecules
Thin = actin molecules
The sliding of Actin past the myosin produces muscle shortening

6. Myofilament Contraction: Watch video then take quiz as a class
hill.com/sites/ /student_view0/chapter10/animation__myofilament_c ontraction.html

7. Sliding Filament Theory: How muscle contract
hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/ / /bio_b.swf::Sarcomere Shortening

8. Muscle Contraction Basics: All or nothing principle
motor
Muscle fibers
____________________neurons excites _______________________ Releases _________________________ excites ______________________ Results in ___________________________________________
Acetycholine
(a neurotransmitter)
sarcolema
A muscle contraction