1. Summation in muscle fibers means that ___________
of the fiber increases with repeated action
potentials.

2. Action potentials are propagated from the surface to the interior of a muscle fiber by way of:
A. the sarcomeres.
B. the sarcoplasmic reticulum.
C. the endomysium.
D. the myofibrils.
E. the T tubules.

3. A cell membrane is referred to as a fluid-mosaic because:
A. it is made up of mostly water
B. it contains many different molecules that are weakly bonded to one another
C. it contains proteins that keep the phospholipids locked rigidly together
D. it permits no molecules to pass into or out of the cell
E. its structure is still a mystery to biologists

4. After the oxidation of glucose is complete, the carbon that was formerly part of glucose is now a part of _______.
A. the electron transport chain.
B. NADH
C. H2O
D. CO2
E. ATP

5. At the END of the electron transport chain, the electrons:
A. are transferred back to NAD+ to make NADH.
B. are transferred back to FAD to make FADFH2
C. combine with H+ and oxygen to make water.
D. combine with carbon and oxygen to make CO2.
E. Both A and B are correct.

6. Which of the following is not found in the thin
filaments of striated muscle?
A. actin
B. myosin
C. troponin
D. tropomyosin
E. Ca+ receptors

7. Design of Muscle
Cellular/Tissue Level
Organ Level
Gettin’ Buff

8. Myofibril

9. Trade-offs in Muscle Design
You Can’t Always Get What You Want

10. Trade-offs in Muscle Design
You cannot build a muscle cell that does it all!
Sarcoplasmic Reticulum
Determines speed of contraction

11. Trade-offs in Muscle Design
You cannot build a muscle cell that does it all!
Myofibrils
Determines force of contraction

12. Trade-offs in Muscle Design
You cannot build a muscle cell that does it all!
Mitochondria
Determines muscle stamina

13. Constraints on Muscle Action
Anaerobic
High Force
Aerobic
Low Force
High Freq
Low Freq

14. Types of Muscle Fibers Mitochondria high low Capillaries high low
Structural Density Slow Oxidative Fast Gylcolytic
Mitochondria high low
Capillaries high low
Glycolytic enzymes low high
Myoglobin high low
Glycogen stores low high
Function
Twitch slow fast
Time to Fatigue long short

15. Types of Muscle Fibers Oxidative Fiber Glycolytic Fiber Red color
Small diameter
“Slow Twitch”
Glycolytic Fiber
Pale color
Large diameter
“Fast Twitch”

16. What Determines Your Fiber Type?
Sprinter Marathon

17. What Determines Your Fiber Type?
Weight training influences muscle development
Sprinter Marathon

18. What Determines Your Fiber Type?
Weight training influences muscle development
Heavy Weight/Low Rep
Low Weight/High Rep
Sprinter Marathon

19. What Determines Your Fiber Type?
Weight training influences muscle fiber development
Heavy Weight/Low Rep
Low Weight/High Rep
Genes
Sprinter Marathon

20. Fast Twitch Muscle Fibers
Rapid ATPase in myosin
Fatigue easily as glycogen
storage is temporary
Short-term, intense movement
50 % of a weighlifter’s muscle
fibers are fast-twitch

21. Slow Twitch Muscle Fibers
Slow ATPase in myosin
Energy from oxidative
phosphorylation
High endurance
80% of a marathon runners
fibers are slow-twitch
Used for standing, walking

22. Keith Richards and Prof. Storm
We share 1 trait in common

23. Keith Richards and Prof. Storm
We share 1 trait in common
Jon and I are keeping our options open

24. Design of Muscle
Cellular/Tissue Level
Organ Level
System Level

25. Motor Units Neuron and the muscle fibers that it innervates.
Fine Control:
Motor unit with few (~20)
muscles
Strength:
Motor unit with many

26. Design of Muscle
Cellular/Tissue Level
Organ Level
Getting Buff’

27. Exercise Influences Muscle Mass
Change in muscle fiber size
No change in number of fibers
More myofibrils in fibers
Muscle overload and trauma

28. Anabolic Androgenic Steroids
Synthetic testosterone
Increase muscle mass
Activate myogenesis genes
Decrease muscle breakdown

29. Muscular Dystrophy Muscle-destroying diseases Onset during childhood
Fat deposition in muscle
Muscle fibers atrophy
Respiratory failure