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Questions and Answers
What transformation is the primary capability of muscle tissue?
What transformation is the primary capability of muscle tissue?
- Conversion of chemical energy (ATP) into directed mechanical energy (correct)
- Conversion of light energy into electrical energy
- Transformation of thermal energy into kinetic energy
- Transformation of mechanical energy into chemical energy
Which characteristic of muscle tissue refers to its capacity to respond to stimuli?
Which characteristic of muscle tissue refers to its capacity to respond to stimuli?
- Extensibility
- Elasticity
- Excitability/Irritability (correct)
- Contractibility
Muscle tissue is characterized by its ability to be stretched. What term best identifies this property?
Muscle tissue is characterized by its ability to be stretched. What term best identifies this property?
- Extensibility (correct)
- Contractibility
- Conductivity
- Elasticity
Which of the following terms is NOT a prefix associated with muscle?
Which of the following terms is NOT a prefix associated with muscle?
What is the primary function of the M-line within a sarcomere?
What is the primary function of the M-line within a sarcomere?
Which type of muscle tissue is known for being both striated and voluntary?
Which type of muscle tissue is known for being both striated and voluntary?
Which type of muscle tissue is found exclusively in the heart?
Which type of muscle tissue is found exclusively in the heart?
Which component of a myofibril is characterized by a lighter region (H zone) in its center?
Which component of a myofibril is characterized by a lighter region (H zone) in its center?
Which muscle tissue type is found in the walls of hollow organs like the stomach and urinary bladder?
Which muscle tissue type is found in the walls of hollow organs like the stomach and urinary bladder?
What defines the boundaries of each sarcomere?
What defines the boundaries of each sarcomere?
If a myofibril is compared to a train, what would the individual sarcomeres be analogous to?
If a myofibril is compared to a train, what would the individual sarcomeres be analogous to?
What describes the primary function of muscles in the human body?
What describes the primary function of muscles in the human body?
Which protein is anchored by the Z disc?
Which protein is anchored by the Z disc?
During repolarization, which ion primarily moves out of the muscle cell?
During repolarization, which ion primarily moves out of the muscle cell?
What is the primary function of the $Na^+$/$K^+$ pump following an action potential?
What is the primary function of the $Na^+$/$K^+$ pump following an action potential?
Which channels are activated at the axon terminal by the arrival of a nerve impulse?
Which channels are activated at the axon terminal by the arrival of a nerve impulse?
What is the term for the period during which a muscle fiber cannot be stimulated until repolarization?
What is the term for the period during which a muscle fiber cannot be stimulated until repolarization?
During excitation-contraction coupling, where are voltage-sensitive proteins located that respond to the action potential?
During excitation-contraction coupling, where are voltage-sensitive proteins located that respond to the action potential?
What is the direct role of calcium release during excitation-contraction coupling?
What is the direct role of calcium release during excitation-contraction coupling?
What occurs immediately after the entry of calcium into the axon terminal?
What occurs immediately after the entry of calcium into the axon terminal?
What is the main purpose of the excitation-contraction coupling process?
What is the main purpose of the excitation-contraction coupling process?
Which of the following is NOT a primary function of skeletal muscles?
Which of the following is NOT a primary function of skeletal muscles?
What is the function of the perimysium within skeletal muscle tissue?
What is the function of the perimysium within skeletal muscle tissue?
What is the role of a fixator muscle in movement?
What is the role of a fixator muscle in movement?
Which of the following describes a muscle's direct attachment to a bone?
Which of the following describes a muscle's direct attachment to a bone?
Which component of a muscle fiber is responsible for the storage of oxygen?
Which component of a muscle fiber is responsible for the storage of oxygen?
What is the sarcolemma?
What is the sarcolemma?
What is the primary function of an antagonist muscle?
What is the primary function of an antagonist muscle?
What is the role of the epimysium in skeletal muscle?
What is the role of the epimysium in skeletal muscle?
Which of the following is an example of an indirect muscle attachment?
Which of the following is an example of an indirect muscle attachment?
What is the function of glycosomes within muscle fibers?
What is the function of glycosomes within muscle fibers?
Which type of muscle contraction is characterized by a muscle shortening while generating force?
Which type of muscle contraction is characterized by a muscle shortening while generating force?
What is the primary role of creatine phosphate in muscle contraction?
What is the primary role of creatine phosphate in muscle contraction?
Skeletal muscle fibers are classified based on their contraction speed and:
Skeletal muscle fibers are classified based on their contraction speed and:
Which muscle fiber type is characterized by its reliance on aerobic pathways for ATP production and high fatigue resistance?
Which muscle fiber type is characterized by its reliance on aerobic pathways for ATP production and high fatigue resistance?
What is the term for the sustained, quivering contraction that occurs when a muscle is stimulated at a high frequency, before reaching maximal tension?
What is the term for the sustained, quivering contraction that occurs when a muscle is stimulated at a high frequency, before reaching maximal tension?
What is the primary characteristic of fast glycolytic muscle fibers?
What is the primary characteristic of fast glycolytic muscle fibers?
Which of the following describes a threshold stimulus in muscle contraction?
Which of the following describes a threshold stimulus in muscle contraction?
Which of the following exercises primarily leads to an increase in muscle fiber size?
Which of the following exercises primarily leads to an increase in muscle fiber size?
Which of the following best describes muscle tone?
Which of the following best describes muscle tone?
What adaptation typically occurs in response to aerobic exercise, such as swimming?
What adaptation typically occurs in response to aerobic exercise, such as swimming?
What is the term used to describe the increase in contraction force by stimulating more muscle fibers?
What is the term used to describe the increase in contraction force by stimulating more muscle fibers?
In the size principle of recruitment, which motor units are typically activated first?
In the size principle of recruitment, which motor units are typically activated first?
What is disuse atrophy?
What is disuse atrophy?
If a muscle is paralyzed and undergoes disuse atrophy, what can typically be expected if no rehabilitation is initiated?
If a muscle is paralyzed and undergoes disuse atrophy, what can typically be expected if no rehabilitation is initiated?
What is the term for the type of contraction where the muscle lengthens while generating force?
What is the term for the type of contraction where the muscle lengthens while generating force?
Which process sums multiple muscle twitches to increase force, due to rapid firing from the motor neuron?
Which process sums multiple muscle twitches to increase force, due to rapid firing from the motor neuron?
What primarily dictates the percentage of each muscle fiber type in an individual?
What primarily dictates the percentage of each muscle fiber type in an individual?
Approximately how long can muscle fibers be powered by stored ATP and creatine phosphate?
Approximately how long can muscle fibers be powered by stored ATP and creatine phosphate?
Which muscle fiber type is predominately involved in activities like sprinting and weightlifting?
Which muscle fiber type is predominately involved in activities like sprinting and weightlifting?
What is NOT a typical adaptation that a muscle may undergo in response to aerobic exercise?
What is NOT a typical adaptation that a muscle may undergo in response to aerobic exercise?
What causes smooth and continuous muscle contractions that add up?
What causes smooth and continuous muscle contractions that add up?
What occurs when a stimulus to a muscle is not strong enough to cause a contraction?
What occurs when a stimulus to a muscle is not strong enough to cause a contraction?
When does muscle fatigue occur?
When does muscle fatigue occur?
What is the state of sustained contraction where the muscle tension reaches its maximum?
What is the state of sustained contraction where the muscle tension reaches its maximum?
What is the type of contraction in which the muscle does not change length?
What is the type of contraction in which the muscle does not change length?
Flashcards
Excitable (irritable) Muscle Tissue
Excitable (irritable) Muscle Tissue
The ability of muscle to respond to stimuli. This property allows muscles to contract when triggered by a nerve impulse.
Contractible Muscle Tissue
Contractible Muscle Tissue
The ability of muscle to shorten or contract when stimulated. This allows muscle to generate force and perform actions like movement.
Extensible Muscle Tissue
Extensible Muscle Tissue
The ability of muscles to be stretched or extended without damage. This allows muscle tissue to allow for a full range of motion.
Elastic Muscle Tissue
Elastic Muscle Tissue
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Skeletal Muscle Tissue Characteristics
Skeletal Muscle Tissue Characteristics
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Cardiac Muscle Tissue Characteristics
Cardiac Muscle Tissue Characteristics
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Smooth Muscle Tissue Characteristics
Smooth Muscle Tissue Characteristics
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What is skeletal muscle?
What is skeletal muscle?
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Muscle Contraction and Heat Generation
Muscle Contraction and Heat Generation
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Muscle Contraction
Muscle Contraction
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Sarcolemma
Sarcolemma
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Sarcoplasm
Sarcoplasm
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Glycosomes
Glycosomes
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Myoglobin
Myoglobin
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Prime Mover (Agonist)
Prime Mover (Agonist)
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Antagonist
Antagonist
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Synergist
Synergist
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Fixator
Fixator
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Myofibrils
Myofibrils
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Sarcomere
Sarcomere
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A Bands
A Bands
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H Zone
H Zone
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M Line
M Line
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Repolarization
Repolarization
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Refractory Period
Refractory Period
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Sodium-Potassium Pump (Na+/K+ pump)
Sodium-Potassium Pump (Na+/K+ pump)
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Excitation-Contraction Coupling (E-C Coupling)
Excitation-Contraction Coupling (E-C Coupling)
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Voltage-Sensitive Proteins
Voltage-Sensitive Proteins
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Calcium Release
Calcium Release
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Voltage-Gated Calcium Channels
Voltage-Gated Calcium Channels
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Exocytosis
Exocytosis
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What are the three types of muscle fibers?
What are the three types of muscle fibers?
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What fiber type are all fibers in a motor unit?
What fiber type are all fibers in a motor unit?
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What type of muscle fiber is best for powerful movements?
What type of muscle fiber is best for powerful movements?
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What type of muscle fiber is best for endurance activities?
What type of muscle fiber is best for endurance activities?
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Can exercise change muscle fiber type?
Can exercise change muscle fiber type?
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What happens to muscles with disuse atrophy?
What happens to muscles with disuse atrophy?
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How does aerobic exercise affect muscle tissue?
How does aerobic exercise affect muscle tissue?
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What effect does resistance exercise have on muscle fibers?
What effect does resistance exercise have on muscle fibers?
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Where is smooth muscle found?
Where is smooth muscle found?
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What are the two main criteria for classifying muscle fibers?
What are the two main criteria for classifying muscle fibers?
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Contractility
Contractility
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Extensibility
Extensibility
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Elasticity
Elasticity
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Muscle Twitch
Muscle Twitch
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Wave (Temporal) Summation
Wave (Temporal) Summation
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Unfused (Incomplete) Tetanus
Unfused (Incomplete) Tetanus
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Fused (Complete) Tetanus
Fused (Complete) Tetanus
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Muscle Fatigue
Muscle Fatigue
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Recruitment (Multiple Motor Unit Summation)
Recruitment (Multiple Motor Unit Summation)
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Threshold Stimulus
Threshold Stimulus
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Maximal Stimulus
Maximal Stimulus
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Size Principle
Size Principle
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Muscle Tone
Muscle Tone
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Isotonic Contractions
Isotonic Contractions
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Isometric Contractions
Isometric Contractions
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Study Notes
Muscles and Muscle Tissue
- Muscles make up nearly half of the body's mass
- Muscles transform chemical energy (ATP) into mechanical energy to exert force
- Types of Muscle Tissue: Skeletal, Cardiac, and Smooth
Muscular System
- Enables movement of organs and the body
- Muscles are highly vascularized and innervated
Characteristics of Muscle Tissue
- Excitable/Irritable: Muscles receive and respond to stimuli
- Contractible: Ability to shorten when stimulated
- Extensible: Ability to be stretched
- Elastic: Ability to recoil to resting length
Types of Muscle Tissue
- Skeletal Muscle:
- Forms most of muscles attached to bones
- Long, cylindrical, multinucleated fibers
- Striated appearance
- Voluntary control
- Rapid contractions, powerful
- Cardiac Muscle:
- Found only in the heart
- Branched, striated, uninucleated fibers
- Intercalated discs connect fibers
- Involuntary control
- Steady, rhythmic contractions
- Smooth Muscle:
- Found in walls of hollow organs (e.g., stomach, intestines)
- Spindle-shaped, uninucleated, non-striated fibers
- Involuntary control
- Slow, sustained contractions
Muscle Functions
- Produce movement
- Maintain posture
- Stabilize joints
- Generate heat
Skeletal Muscle Anatomy
- Skeletal muscle is an organ composed of nerve and blood supply, connective tissue sheaths, and attachments.
- Muscles span joints and attach to bones at two points (origin and insertion).
Connective Tissue Sheaths
- Epimysium: surrounds entire muscle
- Perimysium: surrounds fascicles (bundles of muscle fibers)
- Endomysium: surrounds individual muscle fibers
Muscle Fiber Microanatomy and Sliding Filament Model
- Sarcolemma: muscle fiber plasma membrane
- Sarcoplasm: muscle fiber cytoplasm
- Myofibrils: thread-like structures within muscle fibers; made of sarcomeres
- Sarcomeres: repeating units of myofilaments (actin and myosin)
- Actin: thin filaments
- Myosin: thick filaments
- Glycosomes: glycogen storage
- Myoglobin: oxygen storage
- Z discs: anchors for actin filaments
- I bands: light bands, containing only actin filaments
- A bands: dark bands, containing overlapping actin and myosin filaments
- H zone: region within A band containing only myosin filaments
- M line: middle of H zone; anchors myosin filaments
Sarcoplasmic Reticulum and T Tubules
- Sarcoplasmic reticulum (SR): stores calcium (Ca2+)
- T tubules: extensions of sarcolemma that conduct action potentials deep into muscle fibers
- Triad: Area formed by terminal cisternae, t-tubule, and terminal cisternae on other side
Sliding Filament Model of Contraction
- Muscle fibers contract when tension generated by cross-bridges on thin filaments exceeds opposing forces.
- Thin filaments slide past thick filaments, causing overlap
- Contraction ends when cross bridges become inactive.
Nerve Stimulus and Events at the Neuromuscular Junction
- Skeletal muscles are stimulated by signals from motor neurons
- Axons of motor neurons branch and extend to muscle fibers creating neuromuscular junctions.
- Axon terminals and muscle fibers are separated by synaptic cleft, filled with interstitial fluid.
- Motor end plate is the part of muscle membrane at NMJ that contains millions of receptor sites for Acetylcholine (ACh).
Muscle Fiber Contraction: Cross Bridge Cycling
- Four steps:
- Cross Bridge Formation
- Power Stroke
- Cross Bridge Detachment
- Myosin Head "Re-cocking"
Muscle Twitch
- Simplest contraction, resulting from a single action potential and recording
- Three phases: Latent, contraction, and relaxation periods
- Factors influence strength and duration (metabolic properties, enzymes).
Graded Muscle Responses
- Varying strength and duration of contractions through multiple stimuli.
Muscle Tone
- Constant, slightly contracted state of all muscles. Helps to maintain posture and support.
Isotonic and Isometric Contractions
- Isotonic contractions: Muscles change length and move load (concentric-shorten or eccentric-lengthen).
- Isometric contractions: Muscle tension increases, but the muscle doesn't change length; load is too heavy.
Energy for Contraction and ATP
- ATP supplies energy to: move and detach cross-bridges, pump Ca2+ back into SR, pump Na+, and K+.
- Creatine Phosphate regeneration of ATP
- Aerobic Respiration: Generates a lot of ATP but slow
- Anaerobic Glycolysis: generates ATP faster but produces less
Muscle Fatigue
- Physiological inability to contract despite stimulation; results from ionic imbalances, oxygen deficit, accumulation of lactic acid, and depletion of energy reserves.
Excess Postexercise Oxygen Consumption (EPOC)
- The amount of oxygen needed after exercise to restore pre-exercise muscle conditions.
Force, Velocity, and Duration of Muscle Contraction
- Factors include: Frequency of stimulation, number of motor units recruited, relative fiber size, and degree of muscle stretch
Whole Muscle Contraction
- Muscle actions are combined to produce graded responses. This is critical for motor control.
- The motor unit- motor neuron plus the associated muscle fibers it stimulates.
- Motor units vary in size, enabling more precise or stronger contractions. Stimulation of more motor units leads to greater force.
Smooth Muscle
- Found in walls of hollow visceral organs (digestive tract, blood vessels)
- Spindle-shaped, uninucleated, non-striated fibers.
- Lack sarcomeres and T tubules
- Contains dense bodies
- Electrically coupled by gap junctions
- Contraction mechanism involves Ca2+, calmodulin, and myosin light chain kinase.
- Contractions are slow and synchronized.
Clinical Homeostatic Imbalances
- Muscular dystrophy: Inherited muscle-destroying diseases.
- Myasthenia gravis: Autoimmune disease where antibodies block ACh receptors, leading to muscle weakness.
- Rigor mortis: Stiffening of muscles after death due to lack of ATP.
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Description
Test your knowledge on muscle tissue characteristics and functions. This quiz covers essential concepts like types of muscle, properties, and structural components. Perfect for students studying anatomy or physiology.
