Transportation of Molecules in the Body

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Which of the following is NOT a component of the cardiovascular system?

Lungs

Kidneys (correct)

Blood vessels

Heart

Which of the following is responsible for the electrical excitation of the heart?

Conducting cells (correct)

Contractile cells

Cardiac muscle fibers

Extracellular recordings

What is the effect of altered serum electrolyte concentrations on the electrocardiogram (ECG)?

Increased amplitude of ECG waves

No effect

Changes in ECG morphology (correct)

Decreased amplitude of ECG waves

What is Laplace's Law in relation to the cardiac cycle?

Describes the pressure-volume relationship in the heart Signup and view all the answers

What is the Fick Principle used for?

Estimating cardiac output Signup and view all the answers

What is the primary mechanism for nervous control of heart rate?

Parasympathetic nervous system Signup and view all the answers

Which process transports molecules throughout the body, including oxygen, in a stream of pumped fluid?

Convection Signup and view all the answers

What is the role of the heart in the circulatory system?

To pump blood throughout the body Signup and view all the answers

What is the term for the time period in which the heart is contracting?

Systole Signup and view all the answers

What is the formula for calculating cardiac output?

Cardiac output = stroke volume * heart rate Signup and view all the answers

What is the term for the constriction of blood vessels due to contraction of smooth muscle cells?

Vasoconstriction Signup and view all the answers

What are the two classes of mechanisms that can alter vessel tone?

Intrinsic and extrinsic Signup and view all the answers

Which layer of the blood vessels consists of smooth muscle cells that provide mechanical strength and contractile force?

Tunica Media Signup and view all the answers

Which type of blood vessels are capable of great degrees of distension and elastic recoil due to the numerous elastic fibers present in the tunica media?

Elastic Arteries Signup and view all the answers

Which class of arteries serves as stiff conduits that are not very prone to collapse, and contains a high proportion of smooth muscle cells but less elastic fibers compared to elastic arteries?

Muscular Arteries Signup and view all the answers

Where does the main resistance to blood flow take place?

Arterioles Signup and view all the answers

What is the innermost layer of all blood vessels called?

Tunica Intima Signup and view all the answers

Which type of blood vessels have the largest veins in the systemic circuit?

Veins Signup and view all the answers

Which equation represents the fundamental relationship between flow, pressure, and vascular resistance?

Flow = \Delta P \cdot R Signup and view all the answers

When a blood vessel constricts, what happens to the blood flow through that vessel?

It decreases Signup and view all the answers

What is the product of cardiac output and total peripheral resistance?

Mean arterial pressure Signup and view all the answers

Which type of blood vessels have one-way valves in the heart and veins?

Veins Signup and view all the answers

Which type of blood vessels give rise to high-resistance vessels called arterioles?

Muscular arteries Signup and view all the answers

What is the function of the kidneys in relation to blood flow?

Filtering blood Signup and view all the answers

According to the text, what is the primary function of the cardiovascular system?

To provide a rapid transport system Signup and view all the answers

What is the diffusion coefficient (D) of most small solutes in dilute aqueous solutions?

10-5 cm2/sec Signup and view all the answers

If the outer layers of the heart were solely dependent on receiving nutrients diffusing from the ventricular lumen, how long would it take for a nutrient to diffuse from the lumen to the outer layers of the epicardium?

Approximately 14 hours Signup and view all the answers

Which of the following is NOT a role of the cardiovascular system?

Regulating body temperature Signup and view all the answers

What is the time needed for oxygen molecules to diffuse the appropriate distances at the interface with the environment (lungs) and between blood vessels and cells?

In the millisecond range Signup and view all the answers

What is the equation that shows the time (t) it takes a molecule to move a distance x in one direction in free solution?

$t = rac{x^2}{2D}$ Signup and view all the answers