The factors responsible for holding the lungs to the thorax wall are ________.
surface tension from pleural fluid and negative pressure in the pleural cavity
The loudness of a person's voice depends on the ________.
force with which air rushes across the vocal folds
The walls of the alveoli are composed of two types of cells, type I and type II. The function of type II is to ________.
) Complete the following statement using the choices below. Air moves out of the lungs when the pressure inside the lungs is
greater than the pressure in the atmosphere.
) Unlike inspiration, expiration is a passive act because no muscular contractions are involved. Expiration, however, depends on two factors. Which of the choices below lists those two factors?
the recoil of elastic fibers that were stretched during inspiration and the inward pull of surface tension due to the film of alveolar fluid
) The statement, "in a mixture of gases, the total pressure is the sum of the individual partial pressures of gases in the mixture" paraphrases ________.
Surfactant helps to prevent the alveoli from collapsing by ________.
interfering with the cohesiveness of water molecules, thereby reducing the surface tension of alveolar fluid
) For gas exchange to be efficient, the respiratory membrane must be ________.
0.5 to 1 micrometer thick
With the Bohr effect, more oxygen is released because a(n) ________.
) decrease in pH (acidosis) weakens the hemoglobin-oxygen bond
The most powerful respiratory stimulus for breathing in a healthy person is ________.
increase of carbon dioxide
In the plasma, the quantity of oxygen in solution is ________.
only about 1.5% of the oxygen carried in dissolved form
) Which of the choices below describes the forces that act to pull the lungs away from the thorax wall and thus collapse the lungs?
the natural tendency for the lungs to recoil and the surface tension of the alveolar fluid
Which of the following does not influence the increase in ventilation that occurs as exercise is initiated?
decrease in lactic acid levels
Which of the following is not an event necessary to supply the body with O2 and dispose of CO2?
blood pH adjustment
Which of the following is not true of the respiratory tract from the medium bronchi to the aveoli?
Resistance to air flow increases due to the increase in cross-sectional diameter.
Which of the choices below determines the direction of respiratory gas movement?
partial pressure gradient
The lung volume that represents the total volume of exchangeable air is the ________.
Because the lungs are filled with fluid during fetal life, which of the following statements is true regarding respiratory exchange?
) Respiratory exchanges are made through the placenta.
The amount of air that can be inspired above the tidal volume is called ________.
Which statement about CO2 is incorrect?
More CO2 dissolves in the blood plasma than is carried in the RBCs
Oxygen and carbon dioxide are exchanged in the lungs and through all cell membranes by ________.
Which respiratory-associated muscles would contract if you were to blow up a balloon?
internal intercostals and abdominal muscles would contract
How is the bulk of carbon dioxide carried in blood?
) as the bicarbonate ion in the plasma after first entering the red blood cells
Which of the choices below is not a role of the pleura?
aids in blood flow to and from the heart because the heart sits between the lungs
Which of the following correctly describes mechanisms of CO2 transport?
attached to the heme part of hemoglobin
The respiratory membrane is a combination of ________.
alveolar and capillary walls and their fused basement membranes
Inspiratory capacity is ________.
the total amount of air that can be inspired after a tidal expiration
A premature baby usually has difficulty breathing. However, the respiratory system is developed enough for survival by ________.
Which of the following statements is true regarding the respiratory rate of a newborn?
The respiratory rate of a newborn is, at its highest rate, approximately 40-80 respirations per minute
Select the correct statement about the neural mechanisms of respiratory control.
The pons is thought to be instrumental in the smooth transition from inspiration to expiration