Chapter 8 Flashcards
Afterload
The pressure against against which the heart must pump blood, determined by the peripheral resistance in the large arteries
Anaerobic Threshold
The point at which the metabolic demands of exercise can no longer be met by available aerobic sources and at which an increase in anaerobic metabolism occurs, reflected by an increase in blood lactate concentration
Cardiovascular Drift
An increase in heart rate during exercise to compensate for a decrease in stroke volume. This compensation helps maintain a constant cardiac output
Central Command
Information originating in the brain that is transmitted to the cardiovascular, muscular, or pulmonary systems
Dyspnea
Labored or difficult breathing
Exercise-Induced Arterial Hypoxemia (EIAH)
A decline in arterial PO2 and arterial oxygen saturation during maximal or near-maximal exercise
Frank-Starling Mechanism
The mechanism by which an increased amount of blood in the ventricle causes a stronger ventricular contraction to increase the amount of blood ejected
Hydrostatic Pressure
The pressure exerted by a stationary column of fluid in a tube
Hyperventilation
A breathing rate or tidal volume greater than necessary for normal function
Maximal Voluntary Ventilation
The maximal capacity to move air into and out of the lungs, usually measured for 12 seconds and extrapolated to a per minute value
Maximum Heart Rate (HRmax)
The highest heart rate value attainable during an all-out effort to the point of exhaustion
Oncotic Pressure
The pressure exerted by the concentration of proteins in a solution, drawing water from regions with lower oncotic pressures
preload
The degree to which the myocardium is stretched before it contracts, determined by factors such as central blood volume
Rate-Pressure Product (RPP)
The mathematical product of heart rate x systolic blood pressure, AKA double product
Resting Heart Rate (RHR)
The heart rate at rest, averaging 60 to 80 beats per minute
Steady-State Heart Rate
A heart rate that is maintained constant at submaximal levels of exercise when the rate of work is held constant
Sympatholysis
The process by which locally released vasodilating substances in exercising muscle compete with, and dominate, the vasoconstrictor influence of sympathetic stimulation
Total Peripheral Resistance (TPR)
The resistance to the flow of blood through the entire systemic circulation
Valsalva Maneuver
The process of holding the breath and attempting to compress the contents of the abdominal and thoracic cavities, causing increased intra-abdominal and intrathoracic pressure
Ventilatory Equivalent for Carbon Dioxide (VCO2)
The ratio of the volume of air ventilated (V2) to the amount of carbon dioxide produce (VCO2)
Ventilatory Equivalent for Oxygen (VO2)
The ratio between the volume of air ventilated (V2) and the amount of oxygen consumed (VO2); indicates breathing economy
Ventilatory Threshold
Older name for the ventilatory breakpoint
