How Well You Know About Hemodynamics? Quiz

2.

The portion of the circulatory system with the largest cross-sectional area:

Capillaries
Arterioles
Large Arteries
Large Veins

Correct Answer

A. Capillaries

Explanation

Capillaries have the largest cross-sectional area in the circulatory system. This is because capillaries are tiny blood vessels that connect arteries and veins. They have thin walls that allow for the exchange of nutrients, oxygen, and waste products between the blood and surrounding tissues. The large number and small size of capillaries result in a significantly larger overall cross-sectional area compared to other blood vessels like arterioles, large arteries, and large veins. This increased surface area facilitates efficient exchange of substances and is crucial for the proper functioning of various organs and tissues in the body.

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3.

Vasoconstriction is elicited by all of the following except:

Carotid artery occlusion
Haemorrhage
Lying down
Asphyxia

Correct Answer

A. Lying down

Explanation

Vasoconstriction is the narrowing of blood vessels, which helps to increase blood pressure. Carotid artery occlusion, haemorrhage, and asphyxia are all conditions that can trigger vasoconstriction as a physiological response to maintain blood flow and pressure. However, lying down does not typically elicit vasoconstriction. In fact, when a person lies down, blood flow to various parts of the body may increase due to the absence of gravity, leading to vasodilation instead.

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4.

The linear velocity of blood at the normal cardiac output in the aorta.

32 cm/s
64 cm/s
8 cm/s
50 cm/s

Correct Answer

A. 32 cm/s

Explanation

At the normal cardiac output, the linear velocity of blood in the aorta is 32 cm/s. This means that the blood is flowing at a rate of 32 centimeters per second in the aorta. The linear velocity of blood is an important factor in determining the efficiency of blood flow and the delivery of oxygen and nutrients to the body's tissues. A velocity of 32 cm/s is within the normal range for blood flow in the aorta and indicates healthy blood circulation.

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5.

Laminar flow will occur in conditions in which Reynold’s number.

More than 3000
Less than 3000
Less than 2000
More than 2000

Correct Answer

A. Less than 2000

Explanation

Laminar flow occurs when the Reynolds number is less than 2000. The Reynolds number is a dimensionless quantity that represents the ratio of inertial forces to viscous forces in a fluid flow. When the Reynolds number is below 2000, the flow is characterized by smooth and orderly movement of the fluid particles, with minimal mixing or turbulence. This typically occurs at low flow velocities or in highly viscous fluids.

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6.

The following facts about arteriole are true except

They have thick muscular walls
They have rich sympathetic innervation
They have smallest internal diameter
The pressure drop is greatest than that across any other vessel

Correct Answer

A. They have smallest internal diameter

Explanation

Arterioles are small blood vessels that connect arteries to capillaries. They have thick muscular walls, allowing them to regulate blood flow and control blood pressure. They also have rich sympathetic innervation, which enables them to respond to changes in the body's needs. The statement "They have the smallest internal diameter" is incorrect because arterioles actually have a larger internal diameter compared to capillaries. This is necessary to facilitate the smooth flow of blood from arteries to capillaries. The pressure drop across arterioles is significant but not the greatest, as the greatest pressure drop occurs across the arterioles' larger counterparts, the arteries.

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7.

Arterioles and capillaries differ as follows

Arterioles have no adventitia
Capillaries have no muscle coat
Capillaries have no intimal layer
Only difference is diameter of lumen
None of the above

Correct Answer

A. Capillaries have no muscle coat

Explanation

Capillaries are the smallest blood vessels in the body and their main function is to facilitate the exchange of gases, nutrients, and waste products between the blood and tissues. Unlike arterioles, capillaries do not have a muscle coat. This is because their thin walls are composed of a single layer of endothelial cells, which allows for easier diffusion of substances. The absence of a muscle coat in capillaries also allows for greater flexibility and adaptability to the changing needs of different tissues. Therefore, the correct answer is that capillaries have no muscle coat.

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1

8.

The murmurs in the circulation are characterictically heard

In the conditions where the viscosity of blood increases
In all situations where there is turbulence
When flow passes suddenly from a narrower to wider vessel
When blood enters the parent vessel

Correct Answer

A. In all situations where there is turbulence

Explanation

The correct answer is "In all situations where there is turbulence." This means that whenever there is turbulence in the circulation, murmurs can be heard. Turbulence refers to the disruption or irregularity in the flow of blood, which can be caused by various factors such as narrowed blood vessels or sudden changes in vessel size. In such situations, the blood flow becomes turbulent and creates audible murmurs that can be detected during a physical examination.

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9.

Windkessel effect is seen in

Aorta
Capillaries
Arterioles
Left ventricular musculature

Correct Answer

A. Aorta

Explanation

The Windkessel effect refers to the ability of the aorta to store and release energy during the cardiac cycle, thus maintaining a continuous flow of blood to the peripheral tissues. This effect is achieved through the elastic properties of the aorta, which allow it to expand during systole and recoil during diastole. The aorta acts as a pressure reservoir, absorbing the force of blood ejected from the left ventricle and then releasing it during diastole, ensuring a continuous flow of blood to the rest of the body. Therefore, the Windkessel effect is specifically seen in the aorta.

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1

10.

Velocity of blood flow is inversely proportional to

Viscocity
Blood flow volume
Cross sectional area
Length

Correct Answer

A. Viscocity

Explanation

The viscosity of a fluid refers to its resistance to flow. In the context of blood flow, if the viscosity of blood increases, it becomes thicker and more resistant to flow. This results in a decrease in the velocity of blood flow. Therefore, the velocity of blood flow is inversely proportional to the viscosity of blood.

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2

How Well You Know About Hemodynamics? Quiz

Blood flow is regulated largely by local metabolic effects in:

Quiz Preview

The portion of the circulatory system with the largest cross-sectional area:

Vasoconstriction is elicited by all of the following except:

The linear velocity of blood at the normal cardiac output in the aorta.

Laminar flow will occur in conditions in which Reynold’s number.

The following facts about arteriole are true except

Arterioles and capillaries differ as follows

The murmurs in the circulation are characterictically heard

Windkessel effect is seen in

Velocity of blood flow is inversely proportional to