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Questions and Answers
Skeletal muscle makes up the ______ muscle mass in the body.
Skeletal muscle makes up the ______ muscle mass in the body.
largest
Which of these are types of muscle?
Which of these are types of muscle?
Which type of muscle is considered voluntary?
Which type of muscle is considered voluntary?
Which type of muscle is responsible for heart contractions?
Which type of muscle is responsible for heart contractions?
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What is a bundle of muscle fibers called?
What is a bundle of muscle fibers called?
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What is the name of the smallest contractile unit of skeletal muscle?
What is the name of the smallest contractile unit of skeletal muscle?
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What are the two main protein filaments involved in muscle contraction?
What are the two main protein filaments involved in muscle contraction?
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What is the name of the theory that explains how skeletal muscles contract?
What is the name of the theory that explains how skeletal muscles contract?
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What is the name of the chemical that is released by a nerve cell to stimulate muscle contraction?
What is the name of the chemical that is released by a nerve cell to stimulate muscle contraction?
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What are the nerve cells that supply impulses to muscles called?
What are the nerve cells that supply impulses to muscles called?
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Muscles can push bones.
Muscles can push bones.
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Muscles work in pairs known as antagonistic pairs.
Muscles work in pairs known as antagonistic pairs.
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One way to remember the origin of a muscle is that it is the point of attachment that remains still when the muscle contracts.
One way to remember the origin of a muscle is that it is the point of attachment that remains still when the muscle contracts.
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The ______ of a muscle is generally its proximal attachment (nearest to the center of the body).
The ______ of a muscle is generally its proximal attachment (nearest to the center of the body).
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The ______ of a muscle is generally at the distal end of the muscle (furthest from the center of the body).
The ______ of a muscle is generally at the distal end of the muscle (furthest from the center of the body).
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When a muscle contracts, it gets longer.
When a muscle contracts, it gets longer.
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The muscle that moves the bone towards the body is a flexor muscle.
The muscle that moves the bone towards the body is a flexor muscle.
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The muscle that moves the bone away from the body is an extensor muscle.
The muscle that moves the bone away from the body is an extensor muscle.
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What are the two main muscles that control the movement of the elbow?
What are the two main muscles that control the movement of the elbow?
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The biceps muscle is an extensor muscle.
The biceps muscle is an extensor muscle.
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The triceps muscle is a flexor muscle.
The triceps muscle is a flexor muscle.
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The biceps muscle is located on the front of the upper arm.
The biceps muscle is located on the front of the upper arm.
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The triceps muscle is located on the back of the upper arm.
The triceps muscle is located on the back of the upper arm.
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Muscles are capable of receiving and responding to stimuli.
Muscles are capable of receiving and responding to stimuli.
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The stimulus for muscle contraction is typically a chemical, such as a neurotransmitter.
The stimulus for muscle contraction is typically a chemical, such as a neurotransmitter.
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The electrical impulse generated in response to a stimulus travels along the length of the muscle cell, causing contraction.
The electrical impulse generated in response to a stimulus travels along the length of the muscle cell, causing contraction.
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Continuous stimulation of a muscle can lead to muscle fatigue and damage.
Continuous stimulation of a muscle can lead to muscle fatigue and damage.
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What are the benefits of neurotransmitters being removed from receptors on the muscle fiber membrane following contraction?
What are the benefits of neurotransmitters being removed from receptors on the muscle fiber membrane following contraction?
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Study Notes
Human Physiological Processes: The Muscular System
- The muscular system accounts for 40-50% of body mass.
- The body includes three types of muscle: skeletal, cardiac, and smooth.
- Skeletal muscle comprises the largest muscle mass.
- Skeletal muscles are attached to bones via tendons, enabling movement.
- Skeletal muscles exhibit various shapes and sizes.
- Muscle cells are elongated and referred to as fibers.
- Skeletal muscles possess the longest muscle fibers.
- These fibers display visible stripes (striations).
- Skeletal muscles are voluntary, meaning their contraction can be consciously controlled.
Muscle Function and Movement
- Muscles operate in pairs known as antagonistic pairs.
- Muscle shortening during contraction is called contraction.
- Muscles pull, not push, on bones to create movement.
- The heart muscle is among the busiest, contracting approximately 100,000 times a day.
- The eyes' surrounding muscles blink roughly 20,000 times daily.
- The gluteus maximus is the largest muscle in the body.
Muscle Structure
- Muscles are comprised of bundles of muscle fibers (cells) encased in connective tissue sheaths.
- Muscle fibers contain myofibrils, smaller fibers that extend through the cell.
- Myofibrils are made up of protein filaments arranged in a patterned sarcomere.
- Sarcomeres are the basic units that allow muscle contraction and are characterized by the overlapping actin and myosin filaments.
- Myosin filaments are thick, and actin filaments are thin.
The Sliding Filament Theory
- Muscle contraction occurs via the sliding filament theory.
- Muscle fibers consist of smaller fibers (myofibrils), which, in turn, house actin and myosin filaments.
- These filaments slide past each other during contraction, shortening the muscle fiber.
- For contraction, an initial nerve impulse (action potential) is crucial.
Muscle Contraction: Nervous Control
- Muscles respond to stimuli, typically chemicals like neurotransmitters released from nerve cells.
- This triggers an electrical impulse that causes muscle contraction.
- A neurotransmitter (e.g., acetylcholine) is released, attaching to receptor sites on the muscle fiber membrane.
- This triggers electrical signals that spread across the muscle, causing contraction.
- Enough muscle cell stimulation results in overall muscle contraction.
- Neurotransmitters are rapidly removed after contraction to prevent muscle spasms.
Muscle Attachment
- The origin of a muscle is its proximal attachment. It is typically the more stationary bone during contraction.
- Insertion is the distal end attachment, the bone that moves during contraction.
- A good example is the origin and insertion of the biceps and triceps muscles of the arm. The triceps' origin is usually on the scapula (shoulder blade) and their insertion point is on the elbow. The biceps' origin is also on the scapula and their insertion point is on the radius in the forearm.
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Description
Explore the intricacies of the muscular system in this quiz, covering muscle types, their functions, and the mechanisms behind movement. Understand the distinctions between skeletal, cardiac, and smooth muscles, and learn how muscles work in pairs to facilitate bodily movement.
