Comprehensive Study Guide: Muscle Tissue and Contraction Mechanisms

1. Winter Review Week

2. Set up for “Memory” • Create flashcards for: • Perimysium • Synergist • Aerobic • Leukocytes • Plasma • Eccentric contraction • Leukemia • Motor Unit • Smooth Muscle • Tendon Homework

3. Types of Muscle

4. Producing Movement • Maintain posture and position • Stabilize joints • Generate heat Function

5. Type I – Slow twitch • Type II – Fast twitch • Type II(a) • Type II(b) Type I v. Type II

6. Oxygen efficient • Necessary for extended muscle contraction (over time) • Longer time before fatige Type I

7. Anaerobic • Speed and strength • Fatigue quickly • Type II(a) • Combination of type I and type II • Type II(b) • Classic fast twitch • Rapid firing Type II

8. In what areas of the body are you likely to NOT find type 1 fibers, only type II fibers? Think Critically

9. What are the 6 parts of that make up muscle tissue? • Muscle Fiber • Endomysium • Fascicle • Perimysium • Epimysium • Tendon Muscle Tissue Anatomy

10. Structure of Muscle

11. At a much smaller level, myofibrils are made up of smaller myofilaments • Myofilaments composed of 2 different types of contractile proteins, Actin and Myosin • Slide past each other to create a shortening (contraction) Actin/Myosin

12. Neuromuscular Junction

13. Neuron

14. All muscle must be stimulated • In between axon and muscle is a neuromuscular junction • Motor axon breaks into several branches called axon terminals • Each branch forms a neuromuscular junction with a single muscle cell • 1 neuron stimulates many muscle fibers • Motor unit – neuron and all the muscles it stimulates Neuromuscular Junction

15. Neuron and muscle fibers DO NOT touch • Separated by small, fluid filled gap called the synaptic cleft • Acetylcholine (neurontransmitter) carries the impulse across the gap and delivers the message • If enough acetylcholine is released, the permeability of the receiver changes, allowing for sodium to enter the surface • Results in possible muscle contraction Neuromuscular Junction

16. Types of Muscle Contraction

17. Types of Muscle Contraction

18. What are the 3 types of muscle contraction? Explain each one • Isometric • Concentric • Eccentric Types of Muscle Contraction

19. Direct Phosphorylation • Phosphorylation of ADP by creatine phosphate (CP) • Creatine Phosphate found in muscles • As ATP depletes, CP and ADP react to create ATP and Creatine • Muscles store about 5x as much CP as ATP • CP stores are quickly depleated as well (15 seconds) REVIEW

20. Aerobic Respiration • At rest, during light or moderate exercise, the majority of ATP used for muscle contraction comes from Aerobic Respiration • 95% • Occurs in mitochondria of the cell • Glucose is broken down to CO2 and water • Energy released from broken bonds are captured in ATP molecules • What happens to the CO2? • 32 ATP per 1 glucose • Slow and requires continuous oxygen and fuel Review

21. Anaerobic glycolysis • Does not require oxygen • Occurs in cytosol • Glucose broken down to pyruvic acid and small amounts of energy are captured in ATP bonds • 2 ATP per 1 glucose • If enough oxygen is present, pyruvic acid enters mitochondria and follows aerobic pathway • When exercise becomes intense, pyruvic acid turns to lactic acid and process is referred to as anaerobic glycolysis Review

22. Muscle fatigue – when muscles are exercised strenuously for a long time • Unable to contract even though it is being stimulated • Contractions will weaken until they are no longer possible • Muscle fatigue due to oxygen deficit • Not able to keep up with oxygen demand • Muscles lack oxygen, lactic acid accumulates Muscle Fatigue and Oxygen Deficit

23. Use the worksheet to sequence the steps of a muscle contraction • Bring to class on Monday Worksheet!

24. Set up for “Memory” • Create flashcards for: • Perimysium • Synergist • Aerobic • Leukocytes • Plasma • Eccentric contraction • Leukemia • Motor Unit • Smooth Muscle • Tendon Homework