Acute Adaptations to Exercise

Flashcards covering key vocabulary and concepts related to the acute adaptations of the cardiovascular and respiratory systems during exercise.

Cardiac Output (Q)

The product of heart rate (HR) and stroke volume (SV); Q = HR x SV.

Heart Rate (HR)

The number of heartbeats per minute; can be influenced by sympathetic and parasympathetic nervous systems.

Stroke Volume (SV)

The amount of blood pumped by the heart with each beat; regulated by end-diastolic volume, average aortic blood pressure, and contractility.

Parasympathetic Nervous System (PNS)

The branch of the autonomic nervous system that lowers heart rate through vagus nerve stimulation.

Sympathetic Nervous System (SNS)

The branch of the autonomic nervous system that increases heart rate and contractility through norepinephrine.

Venous Return (Preload)

The volume of blood returning to the heart, which affects stroke volume.

Afterload

The pressure the left ventricle must overcome to eject blood; inversely proportional to stroke volume.

Cardiac Contractility

The ability of the heart muscle to contract; increased by sympathetic stimulation and circulating catecholamines.

Heart Rate Variability (HRV)

The variation in the time interval between heartbeats; indicates autonomic nervous control of the heart.

Autonomic Nervous System (ANS)

The part of the nervous system that controls involuntary actions such as heartbeat and digestion.

Fick Equation

VO2 = Q × (a-v O2 difference); describes the relationship between cardiac output and oxygen uptake.

Oxygen-Hemoglobin Dissociation Curve

A graph showing how the affinity of hemoglobin for oxygen changes with varying partial pressures of oxygen.

Bohr Effect

The phenomenon where decreased pH (increased acidity) reduces hemoglobin's affinity for oxygen.

V/Q Ratio

The ventilation-perfusion ratio; ideal value is about 1, indicating efficient gas exchange.

Muscle Pump

Mechanism by which contracting skeletal muscles compress veins to aid venous return during exercise.

Respiratory Pump

The process where breathing generates pressure differences that assist venous return.

Hemodynamics

The study of blood flow, pressure, and resistance in the circulatory system.

Acid-Base Balance

The regulation of hydrogen ion concentration (pH) in the body, influenced by ventilation and buffering systems.

Sympatholysis

The local inhibition of sympathetic-induced vasoconstriction during exercise.

Thermoregulation

The body's ability to maintain a stable internal temperature despite external temperature changes.

Heat Acclimation

Physiological adaptations that enhance the body's ability to cope with heat during exercise.

Cardiac Drift

The increase in heart rate during prolonged exercise despite a stable workload; often correlates with rising body temperature.

Chloride Shift

The movement of chloride ions into red blood cells as bicarbonate ions move out; helps maintain charge balance.

Endurance Performance

The ability to sustain prolonged exercise; affected by environmental factors such as heat and humidity.

Pulmonary Circulation

The pathway of blood from the right ventricle to the lungs and back to the left atrium.