Podcast
Questions and Answers
What is the primary function of skeletal muscle?
What is the primary function of skeletal muscle?
What is the role of mitochondria in muscle cells?
What is the role of mitochondria in muscle cells?
Which component directly covers the active sites on G-actin?
Which component directly covers the active sites on G-actin?
What are the globular proteins that make up the strands of actin called?
What are the globular proteins that make up the strands of actin called?
Signup and view all the answers
How do transverse tubules function in muscle cells?
How do transverse tubules function in muscle cells?
Signup and view all the answers
Which type of muscle is primarily responsible for respiration?
Which type of muscle is primarily responsible for respiration?
Signup and view all the answers
What is the function of capillary beds in skeletal muscle?
What is the function of capillary beds in skeletal muscle?
Signup and view all the answers
What stabilizes joints and maintains body positions?
What stabilizes joints and maintains body positions?
Signup and view all the answers
Which protein plays a critical role in muscle contraction regulation and interacts with calcium?
Which protein plays a critical role in muscle contraction regulation and interacts with calcium?
Signup and view all the answers
During muscle contraction, what happens to the active sites on G-actin?
During muscle contraction, what happens to the active sites on G-actin?
Signup and view all the answers
What is the term for the unit of contractile proteins connected in series along the length of muscle?
What is the term for the unit of contractile proteins connected in series along the length of muscle?
Signup and view all the answers
Which structure is responsible for storing calcium in skeletal muscle cells?
Which structure is responsible for storing calcium in skeletal muscle cells?
Signup and view all the answers
Which component of muscle fibers primarily enables elasticity?
Which component of muscle fibers primarily enables elasticity?
Signup and view all the answers
What is the role of the M-line in a sarcomere?
What is the role of the M-line in a sarcomere?
Signup and view all the answers
Which term describes the binding of myosin and actin to pull actin towards the M-line?
Which term describes the binding of myosin and actin to pull actin towards the M-line?
Signup and view all the answers
What is found in the I-band of a sarcomere?
What is found in the I-band of a sarcomere?
Signup and view all the answers
What is the primary role of dystrophin in muscle cells?
What is the primary role of dystrophin in muscle cells?
Signup and view all the answers
Which muscle structure is responsible for dividing muscle fibers into individual units?
Which muscle structure is responsible for dividing muscle fibers into individual units?
Signup and view all the answers
Which of the following best describes the role of myoglobin in muscle tissue?
Which of the following best describes the role of myoglobin in muscle tissue?
Signup and view all the answers
What is the significance of the triad in muscle cells?
What is the significance of the triad in muscle cells?
Signup and view all the answers
Study Notes
Skeletal Muscle
- Skeletal muscles are consciously controlled and responsible for body movement; they are attached to bones.
- Muscle function includes posture maintenance, respiration and heat production.
- Skeletal muscles are made up of muscle fibers (cells) that are long, cylindrical and multinucleated.
- Myoblasts (immature muscle cells) fuse to form muscle fibers.
- Muscle fibers exhibit striations (light and dark bands due to protein organization).
- Skeletal muscles are composed primarily of muscle fibers (cells) surrounded by connective tissues, blood vessels, and nerves.
Muscle Histology
- Sarcolemma: The outer plasma membrane of a muscle cell.
- Sarcoplasm: The cytoplasm of a muscle cell, containing many mitochondria (powerhouses of the cell) for ATP production
- Myofibrils: Highly organized protein structures within muscle cells; they extend the entire length of the cell.
- Myofilaments: Contractile proteins (actin and myosin) form repeating patterns, creating sarcomeres, which are the basic contractile units.
- T-tubules: Invaginations of the sarcolemma, allowing action potentials to reach the interior of the muscle fiber, facilitating calcium release.
- Sarcoplasmic Reticulum (SR) Smooth ER that stores calcium ions and releases them during muscle contractions.
- Terminal cisternae: Enlarged regions of the SR adjacent to T-tubules, important for calcium storage.
- Triad: A unit formed by a T-tubule and two terminal cisternae.
Myofilaments
- Actin (thin filaments): made up of G-actin (globular proteins) with active sites for myosin binding; also includes tropomyosin and troponin.
- Myosin (thick filaments): made up of myosin filaments with heads that can bind to actin, driving contraction.
- Sarcomere: Structural and functional unit of muscle fibers, extending from Z-disc to Z-disc.
- Z-disc: Proteins that connect and organize actin filaments.
- M-line: Protein structure in the middle of the sarcomere, connecting myosin filaments.
- I-band: Region containing only actin filaments.
- H-zone: Region containing only myosin filaments.
- A-band: Region including both myosin and the overlapping portions of actin filaments.
- Cross-bridges: Myosin heads binding to actin during muscle contraction
- Myoglobin: Protein in muscle cells that binds and stores oxygen.
- Glycogen granules: Store carbohydrates for energy.
Gross Anatomy of Skeletal Muscle Structure
- Tendons: Dense connective tissue attaching muscle to bone.
- Fascicles: Bundles of muscle fibers.
- Endomysium: Connective tissue surrounding individual muscle fibers.
- Perimysium: Connective tissue surrounding fascicles.
- Epimysium: Connective tissue surrounding the entire muscle.
- Muscles are made up of multiple fascicles bundled together.
Muscle Fiber Structure and Properties
- Muscle cells are long, cylindrical, and multinucleated, containing myofibrils.
- Muscles can shorten by contracting and can elongate from other forces.
- They exhibit contractility (able to shorten), excitability (respond to APs), extensibility (extend beyond resting length), and elasticity (return to original length after extension).
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Test your understanding of skeletal muscle structure and function in this quiz. Explore key terms such as sarcolemma, myofibrils, and the role of muscle fibers. Perfect for students studying muscle histology and anatomy.
