Mechanism of muscle contraction. The sliding filament Theory The way that muscles actually contract...
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Transcript of Mechanism of muscle contraction. The sliding filament Theory The way that muscles actually contract...
![Page 1: Mechanism of muscle contraction. The sliding filament Theory The way that muscles actually contract and shorten is a theory called the sliding filament.](https://reader035.fdocuments.in/reader035/viewer/2022062320/56649ce65503460f949b3a5c/html5/thumbnails/1.jpg)
Mechanism of muscle contraction
![Page 2: Mechanism of muscle contraction. The sliding filament Theory The way that muscles actually contract and shorten is a theory called the sliding filament.](https://reader035.fdocuments.in/reader035/viewer/2022062320/56649ce65503460f949b3a5c/html5/thumbnails/2.jpg)
The sliding filament Theory
• The way that muscles actually contract and shorten is a theory called the sliding filament theory
• This theory involves the movement of the microscopic thin (actin) and thick (myosin) filaments
![Page 3: Mechanism of muscle contraction. The sliding filament Theory The way that muscles actually contract and shorten is a theory called the sliding filament.](https://reader035.fdocuments.in/reader035/viewer/2022062320/56649ce65503460f949b3a5c/html5/thumbnails/3.jpg)
the Sliding Filament Theory
• In this theory we need to look at the relationship between the actin filament and the myosin filament
• These filaments are going to work together in order to cause the contraction
![Page 4: Mechanism of muscle contraction. The sliding filament Theory The way that muscles actually contract and shorten is a theory called the sliding filament.](https://reader035.fdocuments.in/reader035/viewer/2022062320/56649ce65503460f949b3a5c/html5/thumbnails/4.jpg)
the Sliding Filament Theory
• All over the thick filaments there are small heads that protrude from the body of the filament called myosin heads
• They myosin heads will attach themselves to binding sites on the thin actin filament.
![Page 5: Mechanism of muscle contraction. The sliding filament Theory The way that muscles actually contract and shorten is a theory called the sliding filament.](https://reader035.fdocuments.in/reader035/viewer/2022062320/56649ce65503460f949b3a5c/html5/thumbnails/5.jpg)
the Sliding Filament Theory
• The binding sites are exposed and activated when calcium ions are present
• This allows myosin to bind temporarily to the actin filament
• The myosin then acts as oars to “row” in the thin filament
![Page 6: Mechanism of muscle contraction. The sliding filament Theory The way that muscles actually contract and shorten is a theory called the sliding filament.](https://reader035.fdocuments.in/reader035/viewer/2022062320/56649ce65503460f949b3a5c/html5/thumbnails/6.jpg)
![Page 7: Mechanism of muscle contraction. The sliding filament Theory The way that muscles actually contract and shorten is a theory called the sliding filament.](https://reader035.fdocuments.in/reader035/viewer/2022062320/56649ce65503460f949b3a5c/html5/thumbnails/7.jpg)
Energy for Muscle Contraction
• Muscles always need energy for muscle contraction
• Muscles can only use energy stored in the form ATP (Adenosinetriphosphate)
• Muscles only store 4-6 seconds worth of ATP therefore ATP needs to me made constantly
![Page 8: Mechanism of muscle contraction. The sliding filament Theory The way that muscles actually contract and shorten is a theory called the sliding filament.](https://reader035.fdocuments.in/reader035/viewer/2022062320/56649ce65503460f949b3a5c/html5/thumbnails/8.jpg)
ATP creation
• There are three ways in which ATP is created in the body
• Direct Phosphorylation of ADP
• Aerobic respiration
• Anaerobic respiration
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Direct Phosphorylation of ADP
• The body can directly Phosphorylate ADP into ATP
• This means that ADP and Creatine phosphate come together to set off a reaction that will create ATP and Creatine
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Aerobic Respiration
• Aerobic respiration is how ATP is generated through cellular respiration in the presence of oxygen
• Aerobic respiration involves glycolysis, the Krebs cycle, and the electron transport chain.
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Anaerobic respiration
• The human body can also get ATP from Anaerobic Respiration
• The method of Anaerobic Respiration is the fermentation of lactic acid
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Muscle Fatigue
• If we exercise our muscles strenuously for a long time, muscle fatigue will occur.
• A muscle will become fatigued when it is unable to contract even though it is still be stimulated
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Muscle fatigue
• Without rest an active muscle begins to tire and contracts more weakly until lit finally ceases reacting and stops contracting.
• This is believed to be from the oxygen debt that occurs during prolonged muscle activity.
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Oxygen Debt• The oxygen debt is what happens when a person is not able to take in oxygen fast enough to keep up with the muscles when they are working hard.
• The oxygen debt will cause lactic acid to build up from anaerobic respiration and the muscles supply of ATP will dwindle.