Exercise Physiology and Energy Systems Flashcards

Vocabulary practice cards based on lecture notes covering bioenergetics, metabolism, neuromuscular physiology, and cardiovascular adaptations to exercise.

What are the three energy systems

ATP-PC system, anaerobic glycolysis, and aerobic oxidative system.

What is the ATP-PC system used for

Short, explosive activities lasting about 0–10 seconds.

Does anaerobic glycolysis require oxygen

No, it produces ATP without oxygen.

What are the byproducts of anaerobic glycolysis

Lactate and hydrogen ions (H+).

Which energy system is most efficient

The aerobic oxidative system.

Where does the Citric Acid Cycle occur

In the mitochondria.

What is the purpose of the Electron Transport Chain

To produce large amounts of ATP using oxygen.

What do enzymes do

They speed up chemical reactions by lowering activation energy.

How does temperature affect enzymes

Moderate heat increases activity; excessive heat denatures enzymes.

What is a rate-limiting enzyme

The slowest enzyme that controls pathway speed.

What is ATP

The main energy currency of the cell.

What are NAD and FAD

Electron carriers that transport electrons to the ETC.

What is beta oxidation

Breakdown of fatty acids into acetyl-CoA.

What is oxygen deficit

The lag in oxygen delivery at exercise onset.

What is EPOC

Elevated oxygen consumption after exercise during recovery.

What is lactate threshold

The point where lactate accumulates rapidly in blood.

What is the crossover concept

As exercise intensity increases, carbohydrate use increases and fat use decreases.

What fuel source dominates during high-intensity exercise

Carbohydrates.

What is the Cori Cycle

Lactate is converted back into glucose in the liver.

What is downregulation

A decrease in receptor number or sensitivity.

What is upregulation

An increase in receptor number or sensitivity.

What are second messengers

Intracellular signaling molecules like cAMP.

What hormones does the pancreas secrete

Insulin and glucagon.

What does insulin do

Promotes glucose uptake into cells.

What does glucagon do

Raises blood glucose levels.

How does insulin change during exercise

It decreases.

How does glucagon change during exercise

It increases.

What hormone conserves water during exercise

ADH.

What do epinephrine and norepinephrine do

Increase heart rate, blood pressure, and glycogen breakdown.

What are the divisions of the nervous system

CNS and PNS.

What is the afferent division

Sensory input to the CNS.

What is the efferent division

Motor output from the CNS.

What happens during depolarization

Na+ enters the cell.

What happens during repolarization

K+ exits the cell.

What neurotransmitter activates skeletal muscle

Acetylcholine.

What do muscle spindles detect

Muscle length/stretch.

What do Golgi tendon organs detect

Muscle tension.

What is the size principle

Small motor units are recruited before larger ones.

What is hypertrophy

Increase in muscle fiber size.

What are satellite cells

Cells involved in muscle repair and growth.

What are the two major myofibrillar proteins

Actin and myosin.

What is the sliding filament theory

Actin slides over myosin to produce contraction.

What role does calcium play in contraction

Exposes binding sites on actin.

What role does ATP play in contraction

Powers cross-bridge cycling.

Which fiber type is most fatigue resistant

Type I fibers.

Which fiber type produces the most power

Type IIx fibers.

What is cardiac output

The amount of blood pumped per minute.

What is the formula for cardiac output

Q = HR × SV.

What is preload

The amount of ventricular filling/stretch before contraction.

What is afterload

Resistance the heart pumps against.

What is contractility

The force of cardiac contraction.

What happens to systolic blood pressure during exercise

It increases.

What is the a-vO2 difference

Difference between arterial and venous oxygen content.

What is tidal volume

Amount of air moved per breath.

Where does gas exchange occur

In the alveoli.

What is the Bohr effect

Increased temperature/H+/CO2 shifts curve right, enhancing oxygen unloading.

What is ventilatory threshold

Exponential rise in ventilation during intense exercise.

What are the three training principles

Overload, specificity, and reversibility.

What adaptations increase VO2 max

Increased cardiac output and increased a-vO2 difference.

How does endurance training affect mitochondria

Increases mitochondrial density and volume.

How does training affect fuel use

Increases fat utilization and glycogen sparing.

What is normal blood pH

Approximately 7.4.

What are the major intracellular buffers

Bicarbonate, phosphates, proteins, and carnosine.

How do lungs help regulate pH

By removing CO2 through increased ventilation.

What are the four methods of heat loss

Radiation, conduction, convection, and evaporation.

What is the primary heat loss mechanism during exercise

Evaporation.

How does humidity affect heat loss

High humidity reduces evaporative cooling.

What are adaptations to heat acclimation

Increased plasma volume and earlier sweating onset.