Ventilation perfusion coupling means that more blood flows past functional alveoli than past nonfunctional alveoli
the functions of the nasal conchae are to enhance the air turbulence in the cavity and to increase the mucosal surface area exposed to the air.
The lungs are perfused by two circulations: The pulmonary and the bronchial. The pulmonary circulation is or oxygenation of blood. The bronchial circulation supplies blood to the lung structures(tissues)
Changes in arterial pH can modify respiration rate and rhythm even when carbon dioxide and oxygen levels are normal.
During normal quiet breathing, approximately 750 ml of air moves into and out of the lungs w/ each breath
tidal volume is about 500 mls of air
in chronic bronchitis, mucus production is decreased and this leads to the inflammation and fibrosis of the mucosal lining of the bronchial tree.
more mucus is produced in response to he inflammation, it is not propelled up and out and may plug up the airways, and this leads to fibrosis and damage to the alveoli
the largest amount of CO2 is transported in the bloodstream, in the form of carbonic anhydrase.
Valsalva's maneuver involves closing off the glottis (preventing expiration) while contracting the muscles of expiration, causing and increase in intra-abdominal pressure
The Hering-Breuer reflex is a potentially dangerous response that may cause overinflation of the lung
The walls of the alveoli are composed of two types of cells, type I and type II. the function of type II is to?
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
Which of the choices below is not a factor that promotes oxygen binding to and dissociation from hemoglobin?
number of red blood cells
The ___ regulates smoothing of transitions from inspiration to expiration.
Pontine respiratory center