Muscle Physiology Exam Preparation Flashcards

Vocabulary flashcards covering muscle physiology concepts based on lecture notes.

Perimysium

The connective tissue that surrounds a muscle fascicle.

Myosatellite cells

Cells that repair damaged muscle tissue.

A band

The region in a sarcomere that contains both thick and thin filaments.

Transverse tubules

Structures in muscle cells that contain gated calcium channels to activate contraction.

Motor end plate

The part of the muscle fiber stimulated by a motor neuron.

Action potential

Created by the flow of sodium across the sarcolemma.

Acetylcholine

The chemical secreted by motor neurons at neuromuscular junctions in skeletal muscle.

AChE

Acetylcholinesterase, which ends the stimulation of a muscle fiber.

Voltage gated channels

Channels that allow for the propagation of an action potential across a muscle cell.

Calcium

Triggers the movement of troponin to expose actin’s active site.

Myosin heads

The part of the muscle that ATP binds to.

ATP splitting

The process when energy is released as ATP splits into ADP and inorganic phosphate.

Rigor mortis

A condition caused by the deterioration of the SR and decreased AChE activity.

A band length

The length that stays the same when myofilaments slide.

Concentric contraction

Muscle contraction where tension rises and muscle length shortens, moving a load.

Titin

A protein that is relaxed when muscle fibers are stretched.

A second, more powerful contraction

Occurs when a second stimulus arrives before the muscle relaxes completely.

Muscle tone

A chronic, continual, low-level contraction keeping muscles firm without producing movement.

Aerobic metabolism

Source of 95 percent of the energy demand for resting muscle.

Glycogen

Main source of stored energy molecules in a muscle cell.

ATP production via glycolysis

Gives muscle the advantage of faster ATP production.

Aerobic respiration

Muscle fibers rely on this during moderate activity to meet energy needs.

Slow (oxidative) fibers

Type of muscle fiber with the highest concentration of myoglobin.

Cori cycle

Occurs in the liver, playing a role in energy metabolism.

Epimysium

The fibrous tissue that surrounds the entire muscle.

Endomysium

The delicate connective tissue surrounding individual muscle fibers.

H zone

The region in a sarcomere that contains only thick filaments.

Calcium pumps

Increased activity in the SR contributes to rigor mortis.

Junctional fold

Folds in the motor end plate that increase surface area for neurotransmitter binding.

Sarcolemma

The membrane that encloses a muscle fiber.

Sodium flow

Responsible for creating an action potential in muscle fibers.

Muscle fatigue

Condition that occurs due to prolonged activity without adequate rest.

Muscle contraction

The result of interactions between actin and myosin filaments in muscle fibers.

Creatine phosphate

A molecule that helps quickly replenish ATP in muscle cells.

Fast glycolytic fibers

Type of muscle fiber that relies primarily on anaerobic metabolism for energy.

Intermediate fibers

Muscle fibers that possess properties of both slow and fast twitch fibers.

Neuromuscular junctions

The synapse between a motor neuron and a muscle fiber.

Isometric contraction

Type of muscle contraction where muscle length does not change.

Treppe

The phenomenon of increased strength of contraction with repeated stimulus.

Chloride ions

An ion that does not play a major role in muscle contractions.

Sarcoplasmic reticulum

A specialized endoplasmic reticulum in muscle cells storing calcium.

Muscle fiber types

Differing functionalities of various muscle fibers, including their response to training.

Sarcomere

The functional unit of a muscle fiber.

Lactic acid

A product of anaerobic respiration during intense workouts.

Neurotransmitter

Chemical messengers used in communication between neurons and muscle fibers.

Rigor contraction

State where muscles cannot relax due to lack of ATP.

Electrolytes

Essential nutrients that help with muscle contraction and relaxation.

Muscle hypertrophy

Increase in muscle size resulting from exercise and growth.

Muscle atrophy

Decrease in muscle size due to disuse or disease.

Resting state

Condition of muscle fibers when they are not actively contracting.

Muscle recovery

The process a muscle undergoes after strenuous activity to regain strength.

Exercise physiology

The study of how exercise affects the body, particularly muscle function.

Tension development

The process in muscles of generating force during contraction.

Fatigue resistance

The ability of muscles to maintain performance over time.