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Questions and Answers
What percentage of a person's weight does muscle account for?
What is the basic structural unit of a muscle called?
Which of the following is NOT a function of muscle?
Muscle cells primarily derive their energy from the metabolism of which compound?
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Which type of lever is primarily characterized by the load being between the effort and the fulcrum?
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What structures make up muscle tissue?
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Which of the following is a process by which muscles produce heat?
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What role does muscle tone primarily serve in the body?
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Which type of muscle is mainly responsible for voluntary movement?
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What is a defining characteristic of cardiac muscle?
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What is the shape of non striated muscle cells?
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Which muscle group is primarily responsible for maintaining posture?
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How does the contraction duration of smooth muscle compare to skeletal muscle?
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What is the primary control system for smooth muscle?
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In terms of muscle fiber shape, how does cardiac muscle differ from skeletal muscle?
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Which of the following statements is true regarding striated muscle fibers?
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Study Notes
Muscle Tissue
- Muscle tissue accounts for 40% of a person's weight.
- Muscle is defined as a band of fibrous tissue that can contract, causing movement.
- Myofibrils are the contractile threads of muscles.
- A sarcomere is a basic structural unit of a muscle made up of long fibrous proteins that slide past each other.
- Muscle cells convert chemical energy from ATP, derived from food metabolism, into movement.
Muscle Functions
- Muscle has many functions including posture, stability, mobility, circulation, respiration, digestion, temperature regulation, organ protection, and urination.
Lever Systems
- Lever systems are the coordinated actions of bones and muscles to create movement.
- Levers can be categorized into first order, second order, and third order.
- First order levers are used to generate muscular effort to overcome a load or increase the speed of a movement.
- Second order levers are used to overcome a load.
- Third order levers are used to increase the speed of movement.
Heat Production
- Maintaining a constant body temperature is essential for survival.
Muscle Groups
- There are three main muscle groups: striated, smooth/visceral, and cardiac.
- Striated muscle is also known as skeletal muscle.
- Non-striated muscle is also known as smooth or visceral muscle.
Striated/Skeletal Muscle
- Functions: limb movement and maintaining posture.
- Each muscle fibre is cylindrical and can vary in length between 0.02 to 0.08 mm in diameter.
- They have blood vessels and nerves.
- Under voluntary control.
- Muscle fibres are attached to bones by tendons.
- Each end of the muscle articulates the skeleton.
Non Striated/Smooth/Visceral Muscle
- Found in soft tissues, such as blood vessel walls, lymphatic vessels, and the alimentary canal.
- Allows sustained contraction for long periods.
- Cells are spindle shaped.
- Under the autonomic nervous system.
- Each cell has only one centrally placed nucleus.
- Diameter is 0.005mm to 0.01mm and 0.03mm to 0.2mm long.
Cardiac Muscle
- Found only in the wall of the heart.
- Exhibits rhythmic contractions.
- Under the autonomic nervous system.
- Contains an intrinsic pacemaker system.
- Has intercalated discs.
- Each fibre is roughly rectangular in shape.
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Description
Test your knowledge on muscle tissue, its functions, and the mechanics of lever systems in the human body. This quiz covers the essential components such as myofibrils, sarcomeres, and the categories of levers. Perfect for anyone studying anatomy and physiology.
