stroke volume

(noun)

the volume of blood pumped from one ventricle of the heart with each beat

Related Terms

Examples of stroke volume in the following topics:

  • Blood Pressure

    • The body regulates blood pressure by changes in response to the cardiac output and stroke volume.
    • Cardiac output is the volume of blood pumped by the heart in one minute.
    • It is calculated by multiplying the number of heart contractions that occur per minute (heart rate) times the stroke volume (the volume of blood pumped into the aorta per contraction of the left ventricle).
    • However, cardiac output can also be increased by increasing stroke volume, such as if the heart were to contract with greater strength.
    • Stroke volume can also be increased by speeding blood circulation through the body so that more blood enters the heart between contractions.

  • Other Neurological Disorders

    • Epilepsy and stroke are discussed below.
    • Approximately 75 percent of strokes occur in people older than 65.
    • Risk factors for stroke include high blood pressure, diabetes, high cholesterol, and a family history of stroke.
    • Smoking doubles the risk of stroke.
    • Treatment following a stroke can include blood pressure medication (to prevent future strokes) and (sometimes intense) physical therapy.

  • Lung Volumes and Capacities

    • The volume in the lung can be divided into four units: tidal volume, expiratory reserve volume, inspiratory reserve volume, and residual volume.
    • It is the sum of the expiratory reserve volume, tidal volume, and inspiratory reserve volume.
    • It is, therefore, the sum of the tidal volume and inspiratory reserve volume.
    • It is the sum of the residual volume, expiratory reserve volume, tidal volume, and inspiratory reserve volume. .
    • Tidal volume is the volume of air inhaled in a single, normal breath.

  • ATP and Muscle Contraction

    • As myosin expends the energy, it moves through the "power stroke," pulling the actin filament toward the M-line.
    • At the end of the power stroke, the myosin is in a low-energy position.
    • After the power stroke, ADP is released, but the cross-bridge formed is still in place.

  • Cell Size

    • Cell size is limited in accordance with the ratio of cell surface area to volume.
    • Consider the area and volume of a typical cell.
    • Therefore, as a cell increases in size, its surface area-to-volume ratio decreases.
    • Increased volume can lead to biological problems.
    • The cell on the left has a volume of 1 mm3 and a surface area of 6 mm2, with a surface area-to-volume ratio of 6 to 1, whereas the cell on the right has a volume of 8 mm3 and a surface area of 24 mm2, with a surface area-to-volume ratio of 3 to 1.

  • Limiting Effects of Diffusion on Size and Development

    • Recall that any three-dimensional object has a surface area and volume; the ratio of these two quantities is the surface-to-volume ratio.
    • The surface-to-volume ratio of a sphere is 3/r; as the cell gets bigger, its surface-to-volume ratio decreases, making diffusion less efficient .
    • The image illustrates the comparison of spheres of one to one thousand volume units.
    • The surface-to-volume ratio of a sphere decreases as the sphere gets bigger.
    • The surface area of a sphere is 4πr2 and it has a volume of (4/3)πr3 which makes the surface-to-volume ratio 3/r.

  • The Mechanics of Human Breathing

    • The relationship between gas pressure and volume helps to explain the mechanics of breathing.
    • Boyle's Law is the gas law which states that in a closed space, pressure and volume are inversely related.
    • As volume decreases, pressure increases and vice versa .
    • Due to this increase in volume, the pressure is decreased, based on the principles of Boyle's Law.
    • This graph of data from Boyle's original 1662 experiment shows that pressure and volume are inversely related.

  • Characteristics of Prokaryotic Cells

    • First, we'll consider the area and volume of a typical cell.
    • You may remember from your high school geometry course that the formula for the surface area of a sphere is 4πr2, while the formula for its volume is 4/3πr3.
    • Therefore, as a cell increases in size, its surface area-to-volume ratio decreases.
    • If the cell grows too large, the plasma membrane will not have sufficient surface area to support the rate of diffusion required for the increased volume.
    • Notice that as a cell increases in size, its surface area-to-volume ratio decreases.When there is insufficient surface area to support a cell's increasing volume, a cell will either divide or die.The cell on the left has a volume of 1 mm3 and a surface area of 6 mm2, with a surface area-to-volume ratio of 6 to 1, whereas the cell on the right has a volume of 8 mm3 and a surface area of 24 mm2, with a surface area-to-volume ratio of 3 to 1.

  • Other Hormonal Controls for Osmoregulation

    • The renin-angiotensin-aldosterone system (RAAS) stabilizes blood pressure and volume via the kidneys, liver, and adrenal cortex.
    • This system proceeds through several steps to produce angiotensin II, which acts to stabilize blood pressure and volume.
    • Thus, via the RAAS, the kidneys control blood pressure and volume directly.
    • Antidiuretic hormone or ADH (also called vasopressin) helps the body conserve water when body fluid volume, especially that of blood, is low.
    • The renin-angiotensin-aldosterone system increases blood pressure and volume.

  • Organs with Secondary Endocrine Functions

    • These cells release the hormone atrial natriuretic peptide (ANP) in response to increased blood volume .
    • High blood volume causes the cells to be stretched, resulting in hormone release.
    • In this way, ANP causes a reduction in blood volume and blood pressure, while reducing the concentration of Na+ in the blood.
    • Aldosterone then causes the retention of Na+ and water, raising blood volume.
    • The hormone atrial natriuretic peptide (ANP), released in response to increased blood volume, is produced by endocrine cells in the heart.