B3.3 - Musicales and Mobility Flashcards
What are the key components of synovial joints?
Articular cartilage, joint capsule with synovial fluid, and ligaments.
What is the sliding filament theory?
It describes muscle contraction as the sliding of actin and myosin filaments past each other.
What role do bones and exoskeletons play in locomotion?
They provide anchorage for muscles and act as levers for efficient movement.
What is the function of antagonistic muscle pairs?
They allow for precise control of movement by enabling muscles to both initiate and stop motion.
What are the main components to label in a diagram of the human elbow?
Humerus, radius, ulna, biceps, triceps, articular cartilage, synovial fluid, joint capsule.
What are myofibrils composed of?
They are composed of repeating units called sarcomeres.
What is the role of calcium ions in muscle contraction?
They trigger the movement of tropomyosin, exposing myosin binding sites on actin.
What is the first step in the sliding filament theory?
ATP hydrolysis provides energy for the contraction process.
What indicates a contracted muscle in electron micrographs?
Shorter sarcomeres, narrower H zones, and I bands.
What are flexor and extensor muscles in an insect leg?
Flexor muscles contract to bend the leg, while extensor muscles contract to straighten it.
What are the key components to label in a sarcomere diagram?
Z lines, actin filaments, myosin filaments, light bands (I bands), dark bands (A bands), H zone, M line.
What are the unique characteristics of skeletal muscle fibers?
They are multinucleate, contain specialized sarcoplasmic reticulum, and have many myofibrils.
What indicates a relaxed muscle in electron micrographs?
Longer sarcomeres, wider H zones, and I bands.
What happens when a nerve impulse reaches a muscle fiber?
Calcium ions are released from the sarcoplasmic reticulum, initiating contraction.
What is the function of tropomyosin in muscle contraction?
It blocks myosin binding sites on actin filaments when the muscle is relaxed.
