Podcast
Podcast
Podcast
Something went wrong
Questions and Answers
Questions and Answers
Which characteristic distinguishes skeletal muscle from both cardiac and smooth muscle?
Which characteristic distinguishes skeletal muscle from both cardiac and smooth muscle?
- Involuntary movements
- Single nucleus per cell
- Attachment to the skeleton (correct)
- Presence of striations
What is the correct order, from thickest to thinnest, of the connective tissue layers surrounding muscle?
What is the correct order, from thickest to thinnest, of the connective tissue layers surrounding muscle?
- Epimysium, Perimysium, Endomysium (correct)
- Epimysium, Endomysium, Perimysium
- Perimysium, Endomysium, Epimysium
- Endomysium, Perimysium, Epimysium
During an eccentric contraction, what happens to the muscle's length and tension?
During an eccentric contraction, what happens to the muscle's length and tension?
- Muscle shortens; tension remains constant
- Muscle lengthens; tension decreases
- Muscle lengthens; tension is maintained (correct)
- Muscle shortens; tension increases
During muscle contraction, what is the role of calcium?
During muscle contraction, what is the role of calcium?
Which type of muscle contraction involves no change in muscle length?
Which type of muscle contraction involves no change in muscle length?
If a muscle is described as shortening while generating force against resistance, what type of contraction is occurring?
If a muscle is described as shortening while generating force against resistance, what type of contraction is occurring?
What structural protein is primarily responsible for anchoring the myosin filaments and maintaining their alignment within the sarcomere?
What structural protein is primarily responsible for anchoring the myosin filaments and maintaining their alignment within the sarcomere?
What happens to the length of the actin filaments during muscle contraction?
What happens to the length of the actin filaments during muscle contraction?
How does the mitochondrial content typically differ between Type 1 and Type 2 muscle fibers?
How does the mitochondrial content typically differ between Type 1 and Type 2 muscle fibers?
During sustained, low-intensity exercise, which metabolic characteristic is most utilized by Type 1 muscle fibers?
During sustained, low-intensity exercise, which metabolic characteristic is most utilized by Type 1 muscle fibers?
What is the key characteristic that distinguishes hybrid muscle fibers from pure Type 1 or Type 2 fibers?
What is the key characteristic that distinguishes hybrid muscle fibers from pure Type 1 or Type 2 fibers?
A weightlifter is performing short bursts of very high-intensity exercises. Which energy system is primarily utilized, and which type of muscle fibers are most recruited?
A weightlifter is performing short bursts of very high-intensity exercises. Which energy system is primarily utilized, and which type of muscle fibers are most recruited?
How is the usage of each muscle affected based on the mitochondrial density?
How is the usage of each muscle affected based on the mitochondrial density?
Which metabolic adaptation is most likely to delay the onset of fatigue in Type II muscle fibers?
Which metabolic adaptation is most likely to delay the onset of fatigue in Type II muscle fibers?
What best explains the primary mechanism by which lactic acid contributes to muscle fatigue?
What best explains the primary mechanism by which lactic acid contributes to muscle fatigue?
Which training adaptation would be most effective in increasing the endurance capacity of Type II muscle fibers?
Which training adaptation would be most effective in increasing the endurance capacity of Type II muscle fibers?
What cellular change would be MOST effective for delaying fatigue in Type II muscle fibers?
What cellular change would be MOST effective for delaying fatigue in Type II muscle fibers?
Under what conditions can muscle fibers change permanently from one type to another?
Under what conditions can muscle fibers change permanently from one type to another?
What is the primary role of tropomyosin in muscle contraction?
What is the primary role of tropomyosin in muscle contraction?
Which event directly triggers the conformational change in troponin that initiates muscle contraction?
Which event directly triggers the conformational change in troponin that initiates muscle contraction?
During muscle contraction, what causes the sarcomere to shorten?
During muscle contraction, what causes the sarcomere to shorten?
Where does the energy required for muscle contraction directly come from?
Where does the energy required for muscle contraction directly come from?
In excitation-contraction coupling, what is the role of acetylcholine?
In excitation-contraction coupling, what is the role of acetylcholine?
What is the primary function of T-tubules in muscle cells?
What is the primary function of T-tubules in muscle cells?
What type of receptor does acetylcholine bind to on the muscle cell membrane to initiate excitation-contraction coupling?
What type of receptor does acetylcholine bind to on the muscle cell membrane to initiate excitation-contraction coupling?
Which receptor is directly stimulated by acetylcholine (ACh) at the neuromuscular junction?
Which receptor is directly stimulated by acetylcholine (ACh) at the neuromuscular junction?
What is the role of the sarcoplasmic reticulum (SR) in muscle contraction?
What is the role of the sarcoplasmic reticulum (SR) in muscle contraction?
What is the correct sequence of events in muscle contraction following the arrival of an action potential at the neuromuscular junction?
What is the correct sequence of events in muscle contraction following the arrival of an action potential at the neuromuscular junction?
How does the sliding filament theory explain muscle contraction?
How does the sliding filament theory explain muscle contraction?
What prevents the detachment of myosin from actin after death, leading to rigor mortis?
What prevents the detachment of myosin from actin after death, leading to rigor mortis?
Which of the following events directly leads to the exposure of myosin-binding sites on actin?
Which of the following events directly leads to the exposure of myosin-binding sites on actin?
How does the action potential initiated at the sarcolemma reach the myofibrils located deep within the muscle fiber?
How does the action potential initiated at the sarcolemma reach the myofibrils located deep within the muscle fiber?
What is the direct role of the ryanodine receptor in muscle contraction?
What is the direct role of the ryanodine receptor in muscle contraction?
What is the sequence of events that leads to muscle contraction after an action potential reaches the muscle cell?
What is the sequence of events that leads to muscle contraction after an action potential reaches the muscle cell?
During glycolysis, what is the net production of ATP if the process starts with glycogen rather than glucose?
During glycolysis, what is the net production of ATP if the process starts with glycogen rather than glucose?
How does decreased calcium availability within the sarcoplasmic reticulum (SR) affect muscle contraction?
How does decreased calcium availability within the sarcoplasmic reticulum (SR) affect muscle contraction?
Under aerobic conditions, what is the primary fate of pyruvate produced during glycolysis?
Under aerobic conditions, what is the primary fate of pyruvate produced during glycolysis?
A muscle cell is undergoing intense anaerobic exercise. Which of the following best describes the likely metabolic state?
A muscle cell is undergoing intense anaerobic exercise. Which of the following best describes the likely metabolic state?
Which statement correctly describes the relationship between glycolysis and the citric acid cycle (also known as the Krebs cycle)?
Which statement correctly describes the relationship between glycolysis and the citric acid cycle (also known as the Krebs cycle)?
Questions and Answers
Something went wrong
Flashcards
Flashcards
Cardiac Muscle
Cardiac Muscle
Muscle type found in the heart and characterized by rhythmic contractions.
Smooth Muscle
Smooth Muscle
Muscle type found in the walls of internal organs like the stomach and intestines.
Skeletal Muscle
Skeletal Muscle
Muscle type attached to bones, providing movement via leverage.
Epimysium
Epimysium
Signup and view all the flashcards
Perimysium
Perimysium
Signup and view all the flashcards
Endomysium
Endomysium
Signup and view all the flashcards
Isometric Contraction
Isometric Contraction
Signup and view all the flashcards
Isotonic Contraction
Isotonic Contraction
Signup and view all the flashcards
Type II muscle fiber
Type II muscle fiber
Signup and view all the flashcards
Type I muscle fiber
Type I muscle fiber
Signup and view all the flashcards
Type II fibers
Type II fibers
Signup and view all the flashcards
Type I motor unit
Type I motor unit
Signup and view all the flashcards
Hybrid Fibers
Hybrid Fibers
Signup and view all the flashcards
T-Tubules
T-Tubules
Signup and view all the flashcards
Nicotinic Receptor
Nicotinic Receptor
Signup and view all the flashcards
Sarcoplasmic Reticulum (SR)
Sarcoplasmic Reticulum (SR)
Signup and view all the flashcards
DHP Receptor
DHP Receptor
Signup and view all the flashcards
Ryanodine Receptor
Ryanodine Receptor
Signup and view all the flashcards
ATP's Role: Unbinding
ATP's Role: Unbinding
Signup and view all the flashcards
Rigor Mortis
Rigor Mortis
Signup and view all the flashcards
Troponin's Action
Troponin's Action
Signup and view all the flashcards
Troponin & Tropomyosin
Troponin & Tropomyosin
Signup and view all the flashcards
Sliding Filament Theory
Sliding Filament Theory
Signup and view all the flashcards
Calcium's Role in Contraction
Calcium's Role in Contraction
Signup and view all the flashcards
Muscle Relaxation
Muscle Relaxation
Signup and view all the flashcards
Energy Source for Muscles
Energy Source for Muscles
Signup and view all the flashcards
Excitation-Contraction Coupling
Excitation-Contraction Coupling
Signup and view all the flashcards
Acetylcholine's Role
Acetylcholine's Role
Signup and view all the flashcards
Receptor Binding & Action Potential
Receptor Binding & Action Potential
Signup and view all the flashcards
Fatigue
Fatigue
Signup and view all the flashcards
Type 2 Fibers & Fatigue
Type 2 Fibers & Fatigue
Signup and view all the flashcards
Type 2 Fibers & Glucose
Type 2 Fibers & Glucose
Signup and view all the flashcards
Fiber Type Conversion
Fiber Type Conversion
Signup and view all the flashcards
Lactic Acid & Fatigue
Lactic Acid & Fatigue
Signup and view all the flashcards
Glycogen & Calcium
Glycogen & Calcium
Signup and view all the flashcards
Calcium & Muscle Contraction
Calcium & Muscle Contraction
Signup and view all the flashcards
Glycolysis
Glycolysis
Signup and view all the flashcards
Pyruvate's Destination
Pyruvate's Destination
Signup and view all the flashcards
Pyruvate to Citrate
Pyruvate to Citrate
Signup and view all the flashcards
Flashcards
Something went wrong
Study Notes
Study Notes
- There are three types of muscle: cardiac, smooth, and skeletal.
- Cardiac and smooth muscles share similarities in their contractions.
- Skeletal muscles attach to the skeleton through the lever system.
- Skeletal muscles provides more than one movement.
Muscle Structure
- Connective tissues include the epimysium, perimysium, and endomysium.
- Epimysium is connective tissue.
- Perimysium surrounds the fascicle and is connective tissue which creates muscle bundles
- Endomysium is connective tissue.
- Muscles, tendons and bones are involved in physical movement.
- A muscle contains muscle bundles.
- Muscle bundles are made up of muscle fibers.
- Muscle fibers (cells) contain myofibrils.
- Myofibrils are made up of sarcomeres.
Sarcomere Structure
- Sarcomeres are the basic contractile units of muscle fibers and are what make up Myofibrils
- Z lines define the boundaries of a sarcomere.
- Actin and myosin are the proteins that make up the sarcomere.
- Titin is a protein found in the sarcomere.
Types of Contractions:
- Isometric contractions have no movement with contraction.
- Isotonic contractions have the same force with muscle shortening.
- Concentric contractions have the muscle shortening.
- Eccentric contractions are when the muscle lengthens against resistance.
- Muscle striations are created by actin and myosin.
Troponin and Tropomyosin
- Troponin and tropomyosin are key proteins in muscle contraction.
- Tropomyosin prevents actin from binding to myosin
- When calcium binds to troponin, it causes a conformational change.
- This change moves tropomyosin away from the actin binding site.
- The exposure of the binding site allows myosin to bind to actin.
Sliding Filament
- The sliding filament theory explains how muscles contract.
- Actin slides over myosin during muscle contraction.
- ATP is split into ADP and inorganic phosphate (Pi).
- This action energizes the myosin head.
- The myosin head then attaches to actin, forming a cross-bridge.
- Inorganic phosphate is released.
- The release initiates the power stroke, where the myosin head pivots.
- The actin filament slides toward the M line, and ADP is released.
- A new ATP molecule attaches to the myosin head.
- The link between myosin and actin weakens.
- The cross-bridge detaches.
- The myosin then rebinds to actin, and contraction restarts.
Excitation-Contraction Coupling
- Action potentials from motor neurons stimulate muscle contraction.
- Acetylcholine is the neurotransmitter involved at the neuromuscular junction.
- Neurotransmitter acetylcholine binds to receptors in the skeletal muscle cell
- Receptors trigger another action potential.
- T-tubules transmit action potentials throughout the entire muscle cell, stimulating it
- The sarcoplasmic reticulum (SR) contains calcium, which is needed for muscle contraction
- Action potentials trigger the release of calcium from the SR.
- Calcium binds to troponin, initiating the sliding filament mechanism.
- Calcium concentration degraded so Calcium returns back into the body
ATP and Muscle Contraction
- ATP is needed for myosin to unbind from actin.
- Rigor mortis occurs after death due to the lack of ATP.
- This causes muscles to stiffen due to myosin remaining bound to actin.
Motor Units
- A motor unit consists of an alpha motor neuron and all the muscle fibers it stimulates.
- Muscle length and tension are related.
- There is an optimal resting length for muscle to generate maximum tension.
Muscle Fiber Types
- Muscle fiber types differ is contractile characteristics.
- Muscle fiber types differ is structural characteristics.
- Muscle fiber types differ is enzymatic characteristics.
- Muscle fiber types differ is energy substrate.
- Muscle fiber recruitment follows the size principle.
- Smaller Type I muscle fibers are recruited before larger Type II fibers.
- Humans can use speed quickly with a mix of fiber types.
- Muscle length and tension can be monitored with applications.
- A muscle unit is either type 1 or type 2, and can't contain both.
- People typically have more of one fiber type genetically.
- Fiber types determine muscle characteristics.
- Type I fibers are fatigue-resistant and rely on aerobic metabolism
- Type II fibers are more powerful but fatigue quickly.
Type I Fibers
- Type 1 fibers (Breast & wing-Type 1) are tasty beccause of ↑ fat content
Type 2 Fibers
- Legs-Type 2. less fat content.
- Fiber type can influence athletic performance.
- Fibers can use a combination of both type 1 and 2 characteristics
- Developing more mitochondria content is training
- Hybrid fibers can somewhat convert
- Lactid acid acts as a buffer in mitochondria.
- Type II fibers primarily use glycolysis to make ATP.
- Build up of Ca2+ + H builds
- SR calcium coming out, less Ca2+ binding to troponin, tropomyosin is now in way, myosin can't bind to actin.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Study Notes
Something went wrong
