Term
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Definition
| When an muscle contracts, it typically shortens and pulls the insertion toward the origin. |
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Term
| Describe the characteristics of a Muscle Fiber: |
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Definition
Also called muscle cell
Threadlike shape
Thousands in a muscle
Fibers run the full lenght of the muscle |
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Term
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Definition
| The cell membrane - covering - of a Muscle Fiber |
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Term
| T-Tubules (Transverse Tubules) are locate where? |
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Definition
| Since the T-Tubules are an extension of the Sarcolemma, the entend down from the outermost surfact into the center of the muscle. |
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Term
| What is the function of the T-Tubles? |
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Definition
| To transmit the electrical siginal through the muscle. |
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Term
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Definition
| The cytoplasm of the muscle fiber. |
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Term
| True or False: Muscle Fibers have more than one Nuclei. |
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Definition
True.
Because muscle cells are different from other cells in they are very long, they have several nuclei. |
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Term
| What is the Sacrplasmic Reticulum? |
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Definition
| It is a network of Tubules and Sacs that stretch between the T-Tubles. |
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Term
| What is the function of the Sarcoplasmic Reticulum? |
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Definition
| It stores Calcium which is ESSENTAIL to muscle contraction. |
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Term
| What are the characteristics of myofibrils? |
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Definition
Locates within the muscle fiber.
Bundles of very fine fibers running the entire length of the muscle fiber - thousands of them!
Give an overlapped appearance. |
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Term
| What is responsible for giving muscles their STRIATED look? |
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Definition
The overlapping of thousands of myofibrils.
(Myofibrils are within each muscle fiber and run the length of the muscle fiber.) |
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Term
| True or Flase: Myofibrils are comprised of Thick and Thin Filaments? |
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Definition
True.
It is the overlapping of the thick and thin filaments that give a muscle its striated look. |
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Term
| True or False: Myofilaments are made of protein. |
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Definition
True
The proteins are Actin and Myosin |
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Term
| There are 2 Types of Myofilaments. Name them: |
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Definition
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Term
| Describe Thick and Thin myofilaments: |
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Definition
Thick = Myosin
Thin = (3 proteins) Actin, Troponin and Tropomyosin |
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Term
| True or False: Actin is attracted to Myosin. |
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Definition
False.
Myosin (thick filament) is attracted to Actin (thin filament) |
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Term
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Definition
It is the functional, basic contractile, unit of the muscle fiber.
Sarcomeres are segments from Z disc to Z disc.
Sacromeeres repeat through the entire length of the muscle finer. |
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Term
Define Motor Unit
TB p 271 |
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Definition
| A neuron and all of the muscle fibers it innervates. |
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Term
Define Motor Unit:
TB p 271 |
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Definition
| A neuron and all of the muscle fibers it innervates. |
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Term
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Definition
| Smooth, sustained contractions. Multiple twitches resultin from coordinatied contractions of different motor units within the muscle. |
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Term
| Name two substances we discussed as important: |
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Definition
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Term
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Definition
| A tonic contraction is a continual, partial contraction of a muscle. It is a low level of continuous contraction characteristic of the muscles while we are awake. |
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Term
| Describe the asynchronous nature of muscle action. |
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Definition
In the muscle belly, multiple motors units contract while others rest.
This helps contribute to smooth, fine, and coordinated movements.
It helps in sustainable movements without fatigue. |
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