KINES 331: Exercise Science, Biomechanics, and Bioenergetics

Vocabulary flashcards covering skeletal muscle anatomy, mechanical principles, and exercise bioenergetics based on lecture notes.

Axial Skeleton

The structural division of the skeleton consisting of the skull, vertebral column, ribs, and sternum.

Appendicular Skeleton

The structural division of the skeleton consisting of the shoulder girdle, arms, pelvic girdle, and legs.

Fibrous Joints

Joint junctions between bones that allow virtually no movement, such as the sutures of the skull.

Cartilaginous Joints

Joint junctions between bones that allow limited movement, such as intervertebral disks.

Synovial Joints

Joint junctions that allow a considerable amount of movement, such as the hips, shoulders, wrists, and ankles.

Motor Unit

A single motor neuron and all of the muscle fibers that it innervates.

Myofibrils

contain apparatus that contracts muscle cell (myosin + actin)

Sarcomere

The smallest contractile unit of skeletal muscle.

Sarcoplasmic Reticulum

stores calcium ions

T-tubules

run through the sarcolemma; discharge action potential which runs throughout muscle fiber simultaneously; this stimulates release of calcium from sarcoplasmic reticulum

Troponin

protein on actin (binds with calcium)

Tropomyosin

protein that attaches rapidly with myosin

Sliding-Filament Theory

A cycle of repetitive events that cause actin and myosin myofilaments to slide over each other, contracting the sarcomere and generating tension in the muscle

All-or-None Principle

The principle stating that all muscle fibers in a motor unit contract and develop force at the exact same time when stimulated.

Muscle Spindles

Proprioceptors located within the muscle cell that sense stretch and facilitate muscle contraction.

Golgi Tendon Organs (GTO)

Proprioceptors located near the myotendinous junction in tendons that activate an inhibitory interneuron in the spinal cord under heavy loads to inhibit muscle contraction.

Agonist

The prime mover muscle that is most directly involved in bringing about a movement.

Antagonist

A muscle that acts to slow down or stop a movement.

Synergist

A muscle that assists indirectly with bringing about a movement.

Mechanical Advantage

The ratio of the moment arm through which an applied force acts compared to the moment arm through which a resistive force acts.

Pennate Muscle

A muscle with fibers that align obliquely with the tendon, creating a featherlike arrangement.

Angle of Pennation

The angle between muscle fibers and an imaginary line between the muscle's origin and insertion.

Concentric Action

A muscle action where the muscle shortens because the contractile force exceeds the resistive force.

Eccentric Action

A muscle action where the muscle lengthens because the contractile force is less than the resistive force.

Isometric Action

A muscle action where muscle length does not change because contractile force equals resistive force.

Neural Adaptations

The primary cause of strength improvement in novices during the first $7\text{--}10\text{ weeks}$ of resistance training.

Phosphagen System

An anaerobic energy system located in the sarcoplasm that provides rapid ATP resynthesis for high-intensity, short-term activities lasting up to $10\text{ seconds}$.

Glycolysis

The breakdown of carbohydrates to resynthesize ATP for moderate- to high-intensity activities lasting from $10\text{ seconds}$ to $3\text{ minutes}$.

Anaerobic Glycolysis (Fast)

A glycolytic pathway in which pyruvate is converted to lactate, yielding faster ATP resynthesis over a limited duration.

Aerobic Glycolysis (Slow)

A glycolytic pathway in which pyruvate is shuttled into the mitochondria to enter the Krebs cycle.

Lactate Threshold (LT)

The exercise intensity at which blood lactate begins an abrupt increase above basal concentration.

Onset of Blood Lactate Accumulation (OBLA)

The second point of inflection where blood lactate shows a second rapid increase during exercise of increasing intensity.

Metabolic Acidosis

An exercise-induced decrease in pH caused by hydrogen ion accumulation during fatigue.

Cori Cycle

The metabolic pathway in which lactate is transported via blood to the liver and converted to glucose.

Oxidative System

The primary aerobic source of ATP at rest and during low-intensity activities lasting longer than $3\text{ minutes}$.

Oxygen Deficit

The anaerobic contribution to the total energy cost of exercise at the start of work before steady-state oxygen uptake is attained.

EPOC

Excess post-exercise oxygen consumption (or oxygen debt), where oxygen uptake remains elevated above pre-exercise levels during recovery.

High-Intensity Interval Training (HIIT)

Brief repeated bouts of high-intensity exercise with intermittent recovery periods designed to maximize time spent at or above $90\%$ of $\text{VO}_2\text{max}$.