Title: MUSCULAR SYSTEM
1MUSCULAR SYSTEM
2Anatomy of Muscle
Fascia (Dense CT) Epimysium
Perimysium Fascicles Endomysium Fibers Sarcole
mma Myofibrils
3(No Transcript)
4Fascia and Muscle 10x
5Deep Fascia 100x
6Muscle Fiber and Myofibrils
7The Sarcomere
8A Sarcomere
9Construction Site
10Sarcomere
11The Filaments of Myofibrils
12Myosin
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14Steps of Cross-bridge Cycle
- 1. Attachment of cross-bridge to actin
- 2. Movement of cross-bridge
- 3. Detachment of cross-bridge
- 4. Energizing cross-bridge
15Step 1
A M-
ADP-Pi A-M-ADP-Pi
16Step 2
A-M-ADP-Pi A-M ADP Pi
17Step 3
A-M ATP A M-ATP
18Step 4
A M-ATP A M-ADP-Pi
19Sliding Filament Theory
20Whats Needed for Contractions
- Myosin, crossbridges
- Actin
- Tropomyosin
- Troponin
- ATP
- Calcium
21Contraction of a Sarcomere
22Shortening of Bands of Sarcomere
23Motor Unit
24Neuromuscular Junction
25Stimulus for Contraction
- Depolarization of axon
- Events at neuromuscular junction
- Neurotransmitter Acetylcholine (Ach)
- Synaptic cleft
- Acetylcholinesterase
- Motor end plate
- Calcium
26Energy Sources for Contraction
- ATP is used during muscle fiber contraction.
- Produced in mitochondria
- Creatine phosphate is used to regenerate ATP.
- Glucose is ultimate source of energy.
27MUSCLE TWITCH
Threshold stimulus Period of relaxation Latent
period Refractory period Period of
contraction All-or-none response
28Summation
29Tetanus
30Motor Units
Recruitment of motor units to increase strength
of muscle contraction.
31Isometric Contraction(Muscle Fiber)
32Isotonic Contraction(Muscle Fiber)
33Effect of Load on Muscle Contraction
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