Muscle Physiology Quiz & Flashcards

Calcium binds to troponin, shifting tropomyosin to expose actin binding sites.

The sarcoplasmic reticulum stores and releases calcium ions needed for muscle contraction.

Intercalated discs are unique to cardiac muscle, aiding in synchronized contraction.

ATP provides the energy required for the myosin head to detach and re-cock during contraction.

Slow-twitch fibers are suited for endurance due to their high fatigue resistance and oxidative capacity.

In isotonic contractions, the muscle changes length while maintaining constant tension.

A muscle twitch is a single, rapid contraction and relaxation of a muscle fiber.

Creatine phosphate quickly regenerates ATP, the energy source for muscle contraction.

Acetylcholine is a neurotransmitter that initiates muscle contraction by binding to receptors on the muscle fiber.

Aerobic respiration provides the most ATP for prolonged activity, using oxygen to produce energy.

Muscle fatigue occurs due to the depletion of energy reserves and accumulation of metabolic byproducts.

Myoglobin stores and releases oxygen to support aerobic respiration in muscle cells.

DOMS is primarily caused by microtrauma to muscle fibers during unaccustomed or intense exercise.

In an isometric contraction, the muscle generates tension without changing its length.

The sarcomere is the basic contractile unit, defined by the region between two Z discs.

Titin stabilizes myosin filaments and contributes to the elasticity and stability of muscle fibers.

Muscle cramps are caused by involuntary and forceful muscle contractions, often due to dehydration or imbalance.

Intercalated discs enable synchronized contraction of cardiac muscle cells by allowing electrical coupling.

Fast-twitch fibers contract quickly and powerfully but fatigue more rapidly than slow-twitch fibers.

Anaerobic glycolysis provides rapid energy supply by breaking down glucose without oxygen during intense exercise.

Muscular dystrophy is a genetic disorder characterized by progressive weakness and degeneration of skeletal muscles.

Mitochondria are responsible for producing ATP, the energy currency of the cell, through aerobic respiration.

T-tubules transmit action potentials deep into the muscle fiber, triggering calcium release for contraction.

Smooth muscle is responsible for involuntary movements and is found in the walls of hollow internal organs.

Muscle hypertrophy is the increase in muscle size due to resistance training and stress-induced adaptations.

Lactic acid accumulation can contribute to muscle fatigue during intense exercise due to pH changes in the muscle.

The Z line anchors actin filaments and defines the boundaries of a sarcomere, the contractile unit.

Muscles generate force by the sliding of actin and myosin filaments past each other, shortening the muscle fiber.

Rigor mortis is the stiffening of muscles after death, caused by calcium influx and ATP depletion.

Muscle atrophy refers to the decrease in muscle fiber size due to inactivity or disease.

The sarcoplasmic reticulum stores calcium ions, which are released to trigger muscle contraction.

Glycogen is a stored form of glucose in muscle cells, used for energy during prolonged exercise.

Muscle tone maintenance keeps muscles in a state of readiness to respond to stimuli by low-level activation.

Actin filaments interact with myosin to facilitate the sliding mechanism that shortens the muscle fiber.

Recruiting more motor units increases muscle strength by activating more muscle fibers for contraction.

Eccentric contraction involves muscle lengthening under tension, often during controlled lowering movements.

The neuromuscular junction transmits nerve signals to muscle fibers, initiating contraction through neurotransmitter release.

Oxygen debt refers to the extra oxygen required after exercise to replenish energy stores and remove metabolic byproducts.

Tropomyosin blocks myosin binding sites on actin in a relaxed muscle, preventing contraction until calcium binds to troponin.

Muscle contraction moves bones by pulling on tendons attached to the skeleton, facilitating joint movement.

Tetanus results from rapid repeated stimulation that prevents muscle relaxation, leading to sustained contraction.

Anaerobic glycolysis converts glucose to energy without oxygen, producing ATP quickly for short bursts of activity.

Muscle and fat are distinct tissues; muscle cannot convert into fat, although they can change in proportion with activity level.

Protein intake provides the necessary amino acids for muscle repair and growth, especially after exercise.

An antagonist muscle opposes the action of an agonist muscle, often relaxing when the agonist contracts.

In concentric contraction, the muscle shortens while generating force, as seen in lifting actions.

Increased temperature enhances enzyme activity and speeds up muscle contraction processes.