Evaluate the applied pressure necessary to inflate

Reference no: EM13503848

After exhalation, human alveoli have an average radius of approximately 0.05 mm. When inflated by inhalation, the radius increases to about 0.10 mm. The normal mucous tissue fluid surrounding the alveoli has a nominal surface tension of about 50 dynes/cm. The presence of the natural surfactant decreases this to about 3.3 dynes/cm (a factor of 15!). Note that the lungs are inflating by applying a negative pressure to body cavity around them, so the signs of your pressure changes might look a little odd at first.

a. The units "dynes/cm" do not look right for surface energy at first glance because of the linear cm units. Convert the two given surface tensions (with and without surfactant) to units of J/m2 to show why dynes/cm units make sense.

b. Using the converted J/m2 units, calculate the applied pressure necessary to inflate the alveoli without the surfactant, in units of Torr.

c. Calculate the applied pressure necessary to inflate the alveoli with the surfactant, in units of Torr.

d. By what factor has the addition of the surfactant changed the inhalation pressure?

Reference no: EM13503848

Questions Cloud

What force does the book apply to the table : A 0.50 kg physics book with dimensions of 25 cm 20 cm is on a table. What force does the book apply to the table

Determine the total cost per unit : Determine the total cost per unit for each product using traditional job-order costing and determine the total cost per unit for each product using activity based costing

Explain binding energy of the ground state of positronium : The broad feature of the spectrum are therefore expected to be hydrogen-like, the differences arising largely from the mass differences. Predict the wavenumbers of the first three lines of the Blamer series of positronium. What is the binding ener..

What speed does the rock have as it strikes the ground : A 16 kg rock, m, is on the edge of a 90 m cliff, h, as shown in Figure 11-20. Assume that air resistance is negligible. What speed does the rock have as it strikes the ground

Evaluate the applied pressure necessary to inflate : Calculate the applied pressure necessary to inflate the alveoli with the surfactant, in units of Torr. By what factor has the addition of the surfactant changed the inhalation pressure

Determine departmental overhead rate : Determine the total cost allocation and departmental overhead rate for the producing departments using the direct method. Show your work and producing departments using the step-down method.

Find the change in kinetic energy of the car : A 1.85 103 kg car, m, has a speed, vi, of 10.5 m/s. The car then hits a tree. The tree doesn't move, and the car comes to rest, Find the change in kinetic energy of the car

Discuss the modigliani and miller propositions : Select 2 companies in the same industry. Using the Internet, conduct research to find the companies' current balance sheets, explain their capital structure, and calculate their EPS.

Prepare the budgets for the first quarter : Prepare the budgets for the first quarter and calculate the total budgeted contribution margin for the first quarter

User Account

All Pages