2. NEUROMUSCULAR JUNCTION
CONSISTS OF:
1. THE AXONAL TERMINAL OF A SOMATIC MOTOR NEURON.
2. SYNAPTIC CLEFT
3. THE MOTOR END PLATE.

3. NEUROMUSCULAR JUNCTION

4. NEUROMUSCULAR JUNCTION

5. NEUROMUSCULAR JUNCTION

6. NEUROMUSCULAR JUNCTION
FOR MORE INFORMATION
SEE MODULE NUMBER 2
OF THE MUSCULAR CD ROM.

7. SLIDING FILAMENT THEORY

8. SLIDING FILAMENT THEORY

9. SLIDING FILAMENT THEORY

10. SLIDING FILAMENT THEORY

11. SLIDING FILAMENT THEORY

12. SLIDING FILAMENT THEORY

13. SLIDING FILAMENT THEORY
FOR MORE INFORMATION
SEE MODULE NUMBER 3
OF THE MUSCULAR CD ROM.

14. MOTOR UNIT
A MOTOR UNIT IS A SOMATIC MOTOR NEURON AND ALL OF THE MUSCULE CELLS IT INNERVATES.
THE NUMBER OF MUSCLE FIBERS PER MOTOR UNIT MAY BE AS HIGH AS SEVERAL HUNDRED OR A FEW AS FOUR.

15. MOTOR UNIT AS A RESULT, STIMULATION OF A
SINGLE MOTOR UNIT CAUSES A WEAK
CONTRACTION OF THE
ENTIRE MUSCLE, OR A NUMBER OF MOTOR UNITS MAY CAUSE A STRONG CONTRACTION OF THE ENTIRE MUSCLE.

16. MUSCLE TWITCH THE RESPONSE, A CONTRACTION FOLLOWED BY RELAXATION, OF A
MUSCLE TO A SINGLE BRIEF
THRESHOLD STIMULUS.

17. THERE ARE THREE PHASES:
MUSCLE CONTRACTION
THERE ARE THREE PHASES:
1. LATENT PERIOD
2. PERIOD OF CONTRACTION
3. PERIOD OF RELAXATION

18. LATENT PERIOD THE PERIOD TIME, USUALLY A FEW MILLISECONDS, AFTER THE
DECISION TO CONTRACT A SKELETAL
MUSCLE AS BEEN MADE AND THE
ACTUAL SHORTING OF THE MUSCLE
HAS OCCURRED.

19. PERIOD OF CONTRACTION THE PERIOD OF CONTRACTION IS
WHEN CROSS BRIDGES ARE ACTIVE,
FROM THE ONSET TO THE PEAK OF
TENSION DEVELOPMENT, AND THE
MYOGRAM TRACING RISES TO A PEAK.

20. PERIOD OF CONTRACTION IF THE TENSION BECOMES GREAT
ENOUGH TO OVERCOME THE
RESISTANCE (WEIGHT BEING
MOVED),THE MUSCLE SHORTENS.

21. PERIOD OF RELAXATION THE PERIOD OF RELAXATION FOLLOWS THE PERIOD OF
CONTRACTION, AND IS THE RESULT
OF Ca2+ ION CONCENTRATION
RETURNING TO NORMAL LEVELS.

22. PERIOD OF RELAXATION THE MUSCLE TENSION DECREASES TO
ZERO AND THE TRACING
RETURNS TO THE BASELINE. IF THE
MUSCLE HAS SHORTENED DURING
CONTRACTION, IT NOW RETURNS TO
ITS INITIAL LENGTH.

23. THREE PHASES OF MUSCLE CONTRACTION

24. GRADED MUSCLE RESPONSES
MUSCLE CONTRACTION CAN BE GRADED
IN TWO WAYS:
1. BY CHANGING THE SPEED OF STIMULATION.
2. BY CHANGING THE STRENGTH OF THE STIMULUS.

25. GRADED MUSCLE RESPONSES
MUSCLE RESPONSES TO AN INCREASE IN THE NUMBER OF STIMULI:
1. TREPPE
2. TEMPORAL (WAVE) SUMMATION
3. INCOMPLETE TETANI
4. COMPLETE TETANI

26. TREPPE
A MUSCLE MUST HAVE BEEN AT REST FOR A PERIOD OF TIME.

27. TREPPE ALL PHASES OF MUSCLE CONTRACTION ARE PRESENT AND HAVE
NOT BEEN ALTERED.

28. TREPPE
THE STIMULI ARE EQUIDISTANCE APART.

29. TREPPE
THE AMOUNT OF TENSION IS INCREASING DUE TO WARMING OF THE MUSCLE. THE INCREASE IN TEMPERATURE CAUSES ENZYMES TO BE MORE EFFECTIVE.

30. TREPPE
THE AMOUNT OF TENSION DEVELOPED, WITH THE SAME STRENGTH OF STIMULUS, INCREASES AND THEN REMAINS THE SAME.

31. MYOGRAMS

32. MUSCLE IS STIMULATED AT AN
INCOMPLETE TETANI
IF THE STIMULUS
STRENGTH IS HELD
CONSTANT AND THE
MUSCLE IS STIMULATED AT AN
INCREASINGLY FASTER
RATE, INCOMPLETE
TETANI RESULTS.

33. INCOMPLETE TETANI ALL PHASE OF MUSCLE CONTRACTION ARE PRESENT.
HOWEVER, THE PERIOD OF RELAXATION IS SHORTED.

34. INCOMPLETE TETANI
THE STIMULI ARE OF THE SAME STRENGTH, HOWEVER, THEY ARE BECOMING CLOSER TOGETHER.

35. INCOMPLETE TETANI
THE AMOUNT OF TENSION IS INCREASING DUE TO AN INCREASE IN THE NUMBER OF Ca2+.

36. COMPLETE TETANUS WHEN ALL EVIDENCE OF MUSCLE RELAXATION
DISAPPEARS AND THE
CONTRACTIONS FUSE
INTO A SMOOTH,
SUSTAINED
CONTRACTION,
COMPLETE TETANUS
RESULTS.

37. COMPLETE TETANUS NOTICE THAT THE PERIOD OF RELAXATION HAS COMPLETELY
DISAPPEARED.

38. COMPLETE TETANUS
THE STIMULI ARE BEING DELIEVED ONE AFTER ANOTHER, WITH NO TIME ELAPSED.

39. COMPLETE TETANUS
THE TENSION HAS PLATEAUED, BECAUSE ALL OF THE MYOFILAMENTS ARE FORMING BONDS. THERE IS A MAXIMUM OF Ca2+ IN THE MYOFIBRIL.

40. MUSCLE TONE MUSCLE TONE KEEPS THE MUSCLES
OF THE BODY FIRM, HEALTHY, AND
READY TO RESPOND TO STIMULI.
IN ADDITION, MUSCLE TONE HELPS
STABLIZE JOINTS AND MAINTAIN
POSTURE.

41. MUSCLE TONE MUSCLE TONE IS THE RESULT OF ASYNCHRONOUS MUSCLE
MOTOR UNIT CONTRACTION.

42. ENERGY FOR CONTRACTION
1. ATP
2. CREATINE PHOSPHATE
3. GLYCOLYSIS
4. AEROBIC CELLULAR RESPIRATION

43. MUSCLE FATIGUE TRUE MUSCLE FATIGUE IS THE RESULT OF BUILD UP OF ACIDIC
COMPOUNDS, MAINLY LACTIC ACID,
A REDUCTION IN THE AMOUNT OF ATP, AND ELECTROLYTE IMBALANCES.