Question

Oxygen-rich blood bound for the body tissues leaves the heart through the aorta, the major blood...

Oxygen-rich blood bound for the body tissues leaves the heart through the aorta, the major blood vessel emerging from the heart. It branches out to the arteries, which in turn branch into smaller vessels called arterioles (little arteries). These then branch into tiny, thin-walled capillaries. Blood travels slowly as the red blood cells squeeze through tiny capillaries. The radius of the aorta is approximately 9.8 mm and the speed of the blood there is 30 cm/s. A typical capillary has a diameter of approximately 6 µm. The flow speed in these capillaries is approximately 0.05 cm/s.

a. Draw a diagram of the blood vessels and indicate on the diagram the comparative flow speeds in these different-sized blood vessels. Discuss the direction and speed expected for the flow and the continuity equation for this system.

b. Using the given data, calculate how many capillaries a typical person would have.

c. What is the relationship between the combined cross-sectional area of the capillaries and the cross-sectional area of the aorta?

Homework Answers

Answer #1

Let
R1 = 9.8 mm = 0.0098 m
v1 = 30 cm/s = 0.3 m/s

d2 = 6 micro m = 6*10^-6 m
v2 = 0.05 cm/s = 5*10^-4 m/s

a)

b) Let N is the number of capallaries that a typical person would have

use continuty equation,

A1*v1 = A2*v2

(pi*R1^2)*v1 = N*(pi*d2^2/4)*v2

==> N = 4*v1/(d2^2*v2)

= 4*0.3/((6*10^-6)^2*5*10^-4)

= 6.67*10^13 <<<<<<<--------------Answer

c) combined cross sectional area of the capaillaries, A2 = N*(pi*d2^2/4)

= 6.67*10^13*(pi*(6*10^-6)^2/4)

= 1886 m^2

cross sectional area of the aorta, A1 = pi*R1^2

= pi*(9.8*10^-3)^2

= 3.02*10^-4 m^2

so, the combined cross-sectional area of the capillaries = (1886/(3.02*10^-4))* the cross-sectional area of the aorta

= 6.24*10^6*the cross-sectional area of the aorta <<<<<<--------Answer

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
The heart pumps blood into the aorta at a rate of 4 L/min. Calculate the average...
The heart pumps blood into the aorta at a rate of 4 L/min. Calculate the average speed of blood if the aorta’s diameter is 2 cm. The aorta branches many times until the blood finally reaches the smallest branch: the capillaries. Each capillary has an average diameter of 6 μm and a length of 1 mm, and the blood slows down to 0.5 mm/s. Calculate the number of capillaries in the body.
The radius of the aorta is about 1.0 cm , and the blood passing through it...
The radius of the aorta is about 1.0 cm , and the blood passing through it has a speed of about 40 cm/s Calculate the average speed of blood flow in the major arteries of the body, which have a total cross-sectional area of about 2.2 cm2 .
The human circulatory system delivers oxygenated blood from the lungs throughout the human body to enable...
The human circulatory system delivers oxygenated blood from the lungs throughout the human body to enable the transport to and from body cells of oxygen, carbon dioxide, nutrients, hormones and blood cells. A variety of sizes of arteries and veins are required to ful?l this need. (a) A typical heartbeat pumps 75 mL of blood over a time span of 0.36 seconds into the aorta. If under this pressure the aorta expands to a diameter of 4.2 mm, what is...
Use the data describing blood flow in the circulatory system from the table below, and assume...
Use the data describing blood flow in the circulatory system from the table below, and assume a typical blood flow rate of 5.0 L per minute. Aorta Arteries Arterioles Capillaries Venules Veins Vena cava Diameter (cm) 2 0.5 0.002 0.0009 0.003 0.5 3 Total area (cm2) 3 20 500 4000 3000 80 7 Part A What is the flow speed in the arterioles? Express your answer with the appropriate units. Part B What is the pressure difference across a 1.0...
1, What does a blood pressure of 120/70 tell you? (A) At the end of ventricular...
1, What does a blood pressure of 120/70 tell you? (A) At the end of ventricular diastole, the left ventricle generates 70 mmHg (B) During atrial systole, the left ventricle generates 120 mmHg (C) During sympathetic activation, the elastic arteries generate 120 mmHg (D) During ventricular systole, the left ventricle generates more than 120 mmHg (E)The aortic semilunar valve closes when aortic pressure reaches 120 mmHg 2.What is responsible for pushing fluid out across the capillary wall into the interstitial...
1. The layer of the heart that is composed mainly of cardiac muscle and forms the...
1. The layer of the heart that is composed mainly of cardiac muscle and forms the bulk of the      heart is the a. endocardium                      b. myocardium                    c. pericardium 2. The chamber of the heart that sends blood to the systemic circulation is the a. left atrium              b. right ventricle         ...
Heat is the Total internal energy of an object Average kinetic energy of molecules Measure of...
Heat is the Total internal energy of an object Average kinetic energy of molecules Measure of potential energy of molecules Same thing as very high temperature The specific heat of copper is 0.093 cal/g⁰C, and the specific heat of aluminum is 0.22  cal/g⁰C. The same amount of energy applied to equal masses, say, 50 g of copper and aluminum, will result in A higher temperature for copper A higher temperature for aluminum The same temperature for each metal Unknown results The...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT