Skeletal Muscle Contraction Physiology

Front

What is muscle fatigue?

Back

Muscle fatigue is a temporary inability of a muscle to maintain its strength of contraction or tension, often due to depletion of energy sources or accumulation of metabolic byproducts.

Front

What neurotransmitter is used at the Neuromuscular Junction?

Back

Acetylcholine is the neurotransmitter that transmits signals from motor neurons to skeletal muscle fibers at the neuromuscular junction.

Front

What is the function of myoglobin in muscle fibers?

Back

Myoglobin is a protein that stores oxygen in muscle fibers, facilitating aerobic respiration during muscle contraction.

Front

Which organelle in muscle fibers increases or decreases with muscle use?

Back

Myofibrils are the organelles in muscle fibers that increase in number and size with muscle use, contributing to muscle hypertrophy.

Front

What structure in skeletal muscle cells is responsible for calcium storage?

Back

The sarcoplasmic reticulum is the organelle responsible for storing calcium ions in skeletal muscle cells, which are essential for muscle contraction.

Front

What role do T-tubules play in muscle contraction?

Back

T-tubules (transverse tubules) transmit action potentials deep into the muscle fiber, ensuring that the contraction signal reaches all parts of the muscle simultaneously.

Front

What causes lactic acid buildup in muscles?

Back

Lactic acid buildup occurs when anaerobic respiration takes place due to insufficient oxygen during intense exercise, leading to muscle fatigue and pain.

Front

How does energy depletion contribute to muscle fatigue?

Back

Energy depletion occurs when the muscle has used most of its available ATP and glycogen, leading to a decrease in the muscle's ability to contract effectively.

Front

What is the role of calcium ions in muscle contraction?

Back

Calcium ions bind to troponin, causing a conformational change that allows myosin to bind to actin, initiating muscle contraction.

Front

What is the significance of the sarcolemma in muscle fibers?

Back

The sarcolemma is the plasma membrane of muscle fibers that plays a crucial role in conducting action potentials and maintaining the internal environment of the muscle cell.