[06] Biophysics of Muscle Contraction Flashcards
What is a muscle contraction?
It is the activation of tension-generating sites within muscle fibers.
What is the role of “Actin” in muscle contraction?
Actin is a protein that forms the contractile filaments of muscle cells and is involved in motion in other types of cells.
What is the role of “Myosin” in muscle contraction?
Myosin is a type of motor protein that interacts with actin to cause muscle contraction.
Define the term “Sarcomere”.
A sarcomere is the basic functional unit of a muscle fiber that contracts.
How does the “Sliding Filament Theory” explain muscle contraction?
It describes how muscle fibers shorten as the thick and thin filaments slide past each other, which causes the sarcomeres to shorten, resulting in muscle contraction.
What are “Motor Neurons” in the context of muscle contraction?
Motor neurons are nerve cells that initiate and provide the stimulus for muscle contraction.
What is an “Action Potential” in the context of muscle contraction?
It’s the electrical signal that travels along the motor neuron to stimulate muscle contraction.
What is the function of “Neuromuscular Junctions”?
Neuromuscular junctions are the synapses between a motor neuron and a skeletal muscle fiber, facilitating signal transmission.
What role does “Acetylcholine” play in muscle contraction?
Acetylcholine is a neurotransmitter that triggers muscle contraction by transmitting signals from nerve cells to muscle cells.
What happens in the “Excitation-Contraction Coupling” process?
It’s the process where a nerve impulse triggers a muscle cell to contract.
What role does calcium play in muscle contraction?
Calcium ions bind to regulatory proteins in muscle cells to enable contraction.
What is “Cross Bridge Cycling” in muscle contraction?
It’s a sequence of events during which myosin heads bind to actin, pull, and then release.
How does ATP contribute to muscle contraction?
ATP provides the energy for the myosin heads to pull the actin filaments inward, causing contraction.
What happens during “Muscle Relaxation”?
Calcium ions are pumped back into the sarcoplasmic reticulum, causing the muscle fibers to return to their resting state.
What is a “Twitch” in the context of muscle contraction?
A twitch is a single rapid contraction and relaxation cycle of a muscle fiber.
