Unit 6: Biofluidic mechanics - Practice Quiz

1 In a Newtonian viscous fluid, the shear stress is directly proportional to which of the following?

2 Which of the following is a common example of a Newtonian fluid?

3 For a Newtonian fluid, viscosity () is best described as:

4 A non-viscous (ideal) fluid is characterized by which property?

5 In a non-viscous fluid flowing through a pipe, the shear stress between fluid layers is:

6 Which property distinguishes a fluid from a solid?

7 Which of the following categories includes both liquids and gases?

8 The SI unit of dynamic viscosity is:

9 Blood is generally classified as which type of fluid?

10 The hematocrit refers to the volume percentage of which blood component?

11 As the hematocrit increases, the viscosity of blood generally:

12 At low shear rates in small vessels, red blood cells tend to form stacked aggregates known as:

13 Which layer is the innermost lining of a blood vessel wall?

14 The middle layer of an artery, rich in smooth muscle and elastic fibers, is called the:

15 Which structural protein provides elasticity to arterial walls, allowing them to stretch and recoil?

16 Vascular remodeling refers to which of the following?

17 Chronic high blood pressure (hypertension) typically causes arterial walls to:

18 Arterioles are primarily responsible for controlling which of the following?

19 Which vessels are the primary site of exchange of oxygen, nutrients, and waste with tissues?

20 Veins commonly contain which structure to prevent the backflow of blood?

21 For a Newtonian fluid, the shear stress is related to the shear rate by . If the shear rate doubles while temperature is held constant, how does the shear stress change?

22 Water flows through a pipe and behaves as a Newtonian fluid. Which plot correctly describes its shear stress versus shear rate relationship?

23 An ideal (non-viscous) fluid is assumed in many introductory analyses. Which consequence follows directly from neglecting viscosity?

24 Bernoulli's equation in its classic form is most directly applicable to which type of flow?

25 Blood is best classified rheologically as which type of fluid at low shear rates?

26 The Fåhraeus–Lindqvist effect describes which observed behavior of blood?

27 If a patient's hematocrit rises significantly due to dehydration, the most likely effect on whole-blood viscosity is that it will:

28 The Casson model is often used for blood because it accounts for which feature not captured by a simple Newtonian model?

29 The tunica media of a large artery is dominated by which components, giving the vessel its recoil and strength?

30 Which layer of a blood vessel is in direct contact with flowing blood and helps regulate permeability and thrombosis?

31 Compared with an artery of similar diameter, a vein typically has:

32 Chronic hypertension often leads to vascular remodeling characterized by:

33 According to the principle underlying vascular remodeling, a chronic increase in blood flow through a vessel tends to cause the vessel to:

34 A fluid is defined mechanically as a substance that:

35 Which pair of properties primarily distinguishes a liquid from a gas within the general category of fluids?

36 For an organism swimming at very low Reynolds number (e.g., a bacterium), propulsion is dominated by:

37 A fish that increases its swimming speed in water experiences drag that, for turbulent high-Reynolds-number flow, scales approximately as:

38 Arterioles are considered the primary resistance vessels because they:

39 Using Poiseuille's law, if an arteriole constricts so its radius decreases by 20% (to ) with all else constant, the resistance to flow increases by a factor of about:

40 Despite having the smallest individual radius, capillaries offer relatively low resistance to overall flow mainly because:

41 For a Newtonian fluid in steady laminar flow between two parallel plates separated by distance , the top plate moves at velocity while the bottom is stationary. If the dynamic viscosity is , what is the shear stress acting on the fluid, and how does it vary across the gap?

42 An idealized non-viscous (inviscid) fluid flows steadily through a horizontal converging nozzle. Which statement correctly describes the consequences of the zero-viscosity assumption in this flow?

43 Blood exhibits shear-thinning behavior well described by the Casson model . Physiologically, why does apparent viscosity decrease as shear rate increases in large arteries?

44 The Fåhræus–Lindqvist effect describes how apparent blood viscosity changes in small tubes. For vessels with diameters roughly between 10 and 300 , what happens and why?

45 Comparing the tunica media of a large elastic artery (e.g., aorta) with that of a muscular artery, which structural difference explains their distinct mechanical roles?

46 Arterioles are the primary site of vascular resistance. Using Poiseuille's law , if an arteriole constricts so its radius decreases by 20%, by approximately what factor does its resistance increase (assuming and constant)?

47 According to the law of Laplace for a thin-walled cylinder, wall tension . In sustained hypertension, how does an artery typically remodel to normalize wall stress ?

48 A microorganism swimming at very low Reynolds number () cannot use reciprocal motion for net propulsion. This constraint is best summarized by which principle?

49 For a fluid element in a flowing continuum, which statement correctly distinguishes a fluid from a solid in terms of mechanical response to shear?

50 Capillaries have extremely thin walls yet do not rupture despite substantial transmural pressure. Which combination of factors, via Laplace's law , best explains this?

51 Veins operate at low pressure and act as capacitance vessels. Their pressure–volume (compliance) curve is highly nonlinear. What best describes venous behavior at low versus high filling?

52 For fully developed laminar Newtonian flow in a rigid circular tube of radius , the velocity profile is parabolic. What is the ratio of the maximum (centerline) velocity to the mean velocity?

53 The Casson model gives blood a yield stress . What is the practical physiological consequence of this yield stress in the microcirculation during very low-flow states?

54 The three tunicae of a vessel bear load differently. In the physiological pressure range of a large artery, which component dominates load-bearing, and what happens at higher pressures?

55 Chronic increases in blood flow (elevated wall shear stress sensed by the endothelium) typically drive outward remodeling. Which mediator and geometric outcome are correctly paired?

56 The Reynolds number determines the propulsion regime. A bacterium (, ) and a fish (, ) differ enormously in . What is the key propulsive implication?

57 Consider a fluid whose apparent viscosity increases with shear rate. How is this behavior classified, and which everyday example fits?

58 Two Newtonian fluids A and B have the same dynamic viscosity , but fluid A is twice as dense as fluid B. In identical pipe flow geometry driven at the same mean velocity, how do their Reynolds numbers and kinematic viscosities compare?

59 The endothelium (part of the tunica intima) is not merely a passive lining. Which mechanotransduction role best explains its central importance in vascular biology?

60 The Windkessel model treats large arteries as a compliant reservoir. During diastole, blood continues to flow forward even though the heart is not ejecting. What mechanism accounts for this, and which parameter governs the diastolic pressure decay?