The Circulation: Overview of the Circulation; Medical Physics of Pressure, Flow, and Resistance

What is the primary function of the arteries in the circulatory system?

What percentage of the entire blood volume of the body is in the systemic circulation?

According to the principle of blood flow velocity, if the total cross-sectional area of a vessel segment increases, what happens to the velocity of blood flow?

What is the approximate average functional pressure in most systemic vascular beds?

Which of the following is NOT one of the three basic principles that underlie all functions of the circulatory system?

What is the relationship between blood flow, pressure difference, and resistance, as described by Ohm's law for the circulatory system?

What is the term for the overall blood flow in the total circulation of an adult person at rest, which is approximately 5000 ml/min?

How much more pressure does one millimeter of mercury (mm Hg) represent compared to one centimeter of water (cm H2O)?

What is the calculated total peripheral resistance for a normal adult human with a cardiac output of 100 ml/sec and a pressure difference of 100 mm Hg between systemic arteries and veins?

By how much does the conductance of a vessel increase if its diameter increases fourfold, assuming streamlined blood flow?

What does Poiseuille's law demonstrate about the rate of blood flow in relation to the vessel radius?

When blood vessels are arranged in parallel circuits, how is the total vascular resistance calculated?

What is the primary factor that makes blood viscous?

If a person's hematocrit rises to 60 or 70, as in polycythemia, how can blood viscosity change compared to that of water?

What is the phenomenon called where each tissue can adjust its vascular resistance to maintain normal blood flow during changes in arterial pressure between approximately 70 and 175 mm Hg?

In a passive vascular bed, what is the effect of an increased arterial pressure on blood flow, beyond what is predicted by Poiseuille's equation?

What is the primary characteristic of turbulent blood flow?

At what range of Reynolds' number does turbulent flow typically begin to occur at some branches of vessels?

According to the Law of Laplace, how is vascular wall tension (T) related to transmural pressure (ΔP) and the vessel's radius (r) and wall thickness (h)?

What is the approximate total cross-sectional area of all systemic capillaries combined?

The velocity of blood flow is slowest in which part of the circulation?

What is the typical length of time blood remains in the capillaries under resting conditions?

What is the average mean arterial pressure in the pulmonary artery?

If a blood vessel has a pressure of 100 mm Hg at both of its ends, what will be the rate of blood flow?

What is the approximate total pulmonary vascular resistance, calculated in PRU?

What is the term for the reciprocal of resistance, which measures blood flow through a vessel for a given pressure difference?

Which part of the systemic circulation accounts for about two thirds of the total systemic resistance to blood flow?

What is the viscosity of normal whole blood compared to the viscosity of water?

In a patient with polycythemia, what is the primary reason for retarded blood flow?

What is the term for the pressure level below which flow ceases in a passive vascular bed because the blood vessels have completely collapsed?

The phenomenon of a parabolic velocity profile, where the centralmost portion of blood flows fastest, is characteristic of which type of blood flow?

In the proximal aorta and pulmonary artery, Reynolds' number can rise to several thousand during the rapid phase of ventricular ejection. What does this cause?

What is the average systolic and diastolic pressure in a healthy young adult's aorta under resting conditions?

Why do the kidneys play a major role in long-term pressure control, according to the basic principles of circulatory function?

Comparing the cross-sectional areas of veins and arteries of corresponding sizes, how much larger is the area of the veins on average?

What is the approximate percentage of the body's total blood volume contained within the systemic arterioles and capillaries?

What is the primary purpose of the arterioles in the circulatory system?

What is the approximate total peripheral resistance in a condition where all blood vessels in the body become greatly dilated?

When calculating total resistance for blood vessels arranged in series, what method is used?

What is the hematocrit of a normal adult man, on average?

In a passive vascular bed, a decrease in arterial pressure leads to what change in vascular resistance?

According to the text, under what conditions will turbulent flow usually occur even in a straight, smooth vessel?

What is the primary purpose of vascular shear stress in the vascular system?

What is the approximate velocity of blood flow in the aorta under resting conditions?

What is the main reason that the mean pulmonary arterial pressure is much lower than the mean aortic pressure?

How does the heart typically respond to an increased inflow of blood from the veins?

In the relationship R = ΔP/F, what does R represent?

What is the approximate viscosity of blood plasma compared to that of water?

When an increase in arterial pressure initiates compensatory increases in vascular resistance within a few seconds, this is an example of what mechanism?

What is the primary reason why veins can serve as a major reservoir of extra blood?