the difference in the oxygen content of the blood (ml/100ml) as measured when it leaves the heart after being oxygenated by the lungs versus upon its return to the heart (i.e., the amount of oxygen extracted by the body).
autoregulation
the name given to a bodies ability to control the arteriole blood flow at localized areas of the body. This occurs due to chemical changes at the local level such as lowered oxygen levels which cause the arteriole to dilate.
cardiac cycle
all the events of the heart operation between two consecutive heart beats.
cardiac output (Q)
the total volume of blood pumped by the heart per minute. The product of heart rate and stroke volume.
end-diastolic volume
the volume of blood contained in the ventricle at the end of the diastole (prior to its contraction).
end-systolic volume
the volume of blood contained in the ventricle at the end of the systole (just after its contraction).
extrinsic neural control
control of blood flow directed by sympathetic nervous system which redirects blood flow from areas of low need to areas of high need by constricting or relaxing arterioles
hematocrit
the ratio of blood volume composed of cells or formed elements to total blood volume.
hemoconcentration
the name given to the effect of increased hematocrit due to loss of blood plasma during exercise
hemoglobin
a molecule of the red blood cell which oxygen binds to allowing for the transport of oxygen through the blood stream.
hypertension
chronically elevated blood pressure above the norm.
maximum heart rate
the highest heart rate attained during an all-out exercise effort to exhaustion
steady-state heart rate
the heart rate attained within a few minutes and sustained during the duration for a particular level of physical exercise.
stroke volume
the volume of blood ejected from the left ventricle per contraction.
anaerobic threshold
the respiration point where the volume of CO2 produced increases at a higher rate when compared to the O2 volume consumed
expiration
the process where gas is expelled from the lungs
external respiration
the name given to the process of bringing air into/out of the lungs and the gas exchange (CO2 and O2) inside the lungs.
hyperventilation
an increase in ventilation occurring without need from a metabolic perspective
inspiration
the active process where the diaphragm and intercostal muscles contract to increase the volume of the thoracic cage which causes a measure drop in the lungs allowing outside air to enter
internal respiration
the name given to the transport of gases (CO2 and O2) in the circulatory system and the gas exchange in the tissues
pulmonary diffusion
the gas exchange in the lungs in which O2 is absorbed and CO2 is removed from the blood
pulmonary ventilation
another name for breathing
respiratory centers
the location in the medulla oblongata which control the rate and depth of breathing
respiratory membrane
the thin tissue area in the lung where the gas exchange occurs in the lungs
Valsalva maneuver
a technique used to increase blood pressure during resistance exercise where a person tries to exhale while the mouth, nose and glottis are closed.
