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Pressure volume relationships - Normal inspiration and expiration

By: HWC, Views: 6578

• Changing the relative pressure in the compartments can control the direction of airflow between compartments. • In a closed compartment, pressure and volume are inversely related. • Reducing the volume will increase the pressure. • Increasing the volume will decrease the pressure. ...

Isovolumetric VC, Ventricular ejection, Isovolumetric & Passive ventricular filling

By: HWC, Views: 6623

• Isovolumetric means that blood volume does not change. • Ventricular blood volume and cell length remain constant. • With valves closed and contraction continuing, ventricular pressure continues to rise. • Ventricular pressure rises above arterial pressure. • Increased ventr...

Stroke volume - afterload definition & hypertension

By: HWC, Views: 6141

• Pressure (or other resisting force) that ventricles must overcome to push open semilunar valves and eject blood. ▪ Normally, the left ventricle blood pressure must overcome arterial pressure in the aorta. ▪ Abnormally high blood pressure, or hypertension, increases aortic pressure w...

Exercise and cardiac output & Definition of stroke volume

By: HWC, Views: 6611

▪ Cardiac output: • Maintains blood flow throughout the body. • Measure of blood volume ejected from the heart over a given time. • Determined by multiplying heart rate by stroke volume (CO = SV x HR). • Heart rate: Number of beats/min. • Stroke volume: Amount of blood eject...

Definitions of stroke volume, preload definition & Factors influencing stroke volume

By: HWC, Views: 6465

• Stroke volume is directly correlated with cardiac output-the greater the stroke volume the greater the cardiac output. • Stroke volume represents the difference in the amount of blood between: • the volume in the ventricles at the end of diastole (end-diastolic volume EDV); • the ...

Renin/Angiotensin (water gain from urine & Na ion and water reabsorption)

By: HWC, Views: 6545

• Sensing declining blood pressure or blood volume, juxtaglomerular cells of the nephron release renin, an enzyme that promotes the formation of angiotensin II. • Angiotensin II targets smooth muscle cells in blood vessels that provide blood to the nephron. • Angiotensin II causes thes...

Antidiuretic hormone (vasoconstriction, water reabsorption & sweat inhibition)

By: HWC, Views: 6589

• Dehydration, blood loss, and low amounts of water in the blood can cause blood volume and pressure to decrease. • Neurosecretoxy cells in the posterior pituitary release antidiuretic hormone(ADH). • ADH binds to smooth muscle cells in blood vessel walls, stimulating them to vasoconstr...

Stroke volume

By: HWC, Views: 6648

Preload definition • Preload is the degree of stretch of cardiac muscles cells prior to contraction. • The amount of stretch is related to the end-diastolic volume[EDV]. • Increased return blood flow from the veins increases end-diastolic volume. Cardiac muscle sarcomeres stretch and ...

ADH and the arterioles, kidneys, sweat glands and the Atrial natriuretic peptide (ANP)

By: HWC, Views: 6781

• ADH is also known as vasopressin. • Produced by hypothalmus and secreted by neurosecretory cells in posterior pituitary gland. • Responds to high blood osmotic pressure representing low amounts of water in the blood. • Binds to smooth muscle cells in walls of arterioles, stimulate...