lesson 10 respiratory system physiology
During normal quiet breathing, approximately 750 ml of air moves into and out of the lungs with each breath.
FALSE
The average individual has 500 ml of residual volume.
FALSE
The most important chemical stimuli leading to increased rate and depth of breathing is:
Hydrogen and carbon dioxide concentration of blood
Unlike inspiration, experiation 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.
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
Inspiratory capacity is:
The total amount of air that can be inspired after a tidal expiration
Tidal volume is air:
exchanged during normal breathing
As carbon dioxide enters systemic blood, it causes more oxygen to dissociate from hemoglobin (the Haldane effect), which in turn allows more CO2 to combine with hemoglobin and more bicarbonate ions to be generated (the Bohr effect).
false
In chronic bronchitis, mucus production is decreased and this leads to the inflammation and fibrosis of the mucosal lining of the bronchial tree.
false
Increased temperature results in decreased O2 unloading from hemoglobin.
false
The Hering-Breuer reflex is a potentially dangerous response that may cause overinflation of the lung.
false
The largest amount of carbon dioxide is transported in the bloodstream in the form of carbonic anydrase.
false
Air moves out of the lungs when the pressure inside the lungs is:
greater than the pressure in the atmosphere
The most powerful respiratory stimulus for breathing in a healthy person is
increase of carbon dioxide
The amount of air that can be inspired above tidal volume is called?
inspiratory reserve
Surfactant helps to prevent the alveoli from collapsing by:
interfering with the cohesiveness of water molecules, thereby reducing the surface tension of alveolar fluid
Respiratory control centers are located in the:
medulla and pons
Which of the choices below is NOT a factor that promotes oxygen binding to and dissociation from hemoglobin?
number of red blood cells
In the plasma, the quantity of oxygen in solution is:
only about 1.5% of the oxygen carried in blood
The Bohr effect refers to the unloading of ________ in a RBC due to declining pH
oxygen
Which of the choices below determines the direction of respiratory gas movement?
partial pressure gradient
Which center is located in the pons?
pontine respiratory group (PRG)
intrapulmonary pressure is the:
pressure within the alveoli of the lungs
A premature baby usually has difficulty breathing. However the respiratory system is developed enough for survival by:
28 weeks
The relationship between gas pressure and gas volume is described by:
Boyle's law
The statement, "in a mixture of gases, the total pressure is the sum of the individual partial pressure of gases in the mixture" paraphrases:
Dalton's law
Which respiratory-associated muscles would contract if you were to blow up a balloon?
Internal intercostals and abdominal muscles would contract
Which of the following is NOT a stimulus for breathing? a.rising carbon dioxide levels b.rising blood pressure c.arterial PO2 below 60 mm Hg d.acidosis resulting from CO2 retention
b. rising blood pressure
Dalton's law states that the total pressure exerted by a mixture of gases is the sum of the pressures exerted independently by each gas in a mixture.
TRUE
Intrapleural pressure is normally about 4 mm Hg less than the pressure in the alveoli.
TRUE
Labored breathing is termed dyspnea.
TRUE
The alveolar ventilation rate is the best index of effective ventilation.
TRUE
ventilation perfusion coupling means that more blood flows past functional alveoli than past non-functional.
TRUE
Select the correct statement about tne enural mechanisms of respiratory control. a.The pons is thought to be instrumental in the smooth transition from inspiration to expiration b.The dorsal respiratory group neurons depolarize in a rhythmic way to establish the pattern of breath c.The pontine respirator group (PRG) continuousy stimulates the medulla to provide inspiratory drive d.The ventral respiratory group is contain within the pons
a.The pons is thought to be instrumental in the smooth transition from inspiration to expiration
which of the following is NOT possible? a.Gas flow equals pressure gradient over resistance b.Pressure gradient equals gas flow over resistance c.Resistance equals pressure gradient over gas flow d.The amount of gas flowing in and out of the alveoli is directly proportional to the difference in pressure or pressure gradient between the external atmosphere and the alveoli
b. Pressure gradient equals gas flow over resistance
How is the bulk of carbon dioxide carried in the blood?
b. as the bicarbonate ion in the plasma after first entering the red blood cells
Which of the following is NOT a form of lung cancer? a.adenocarcinoma b.Kaposi's sarcoma c.small cell carcinoma d.squamous cell carcinoma
b.Kaposi's sarcoma
The nose serves all of teh following functions EXCEPT: a.as a passageway for air movement b.as the direct initiator of the cough reflex c.warming and humidifying the air d.cleansing the air
b.as the direct initiator of the cough reflex
Select the correct statement about the physical factors influencing pulmonary ventilation. a.A decrease in compliance causes an increase in ventilation b.A lung that is less elastic will require less muscle action to perform adequate ventilation c.As alveolar surface tension increases, additional muscle action will be required d.Surfactant helps increase alveolar surface tension
c. As alveolar surface tension increases, additional muscle action will be required
Which statement about CO2 is incorrect? a.Its concentration in the blood is decreased by hyperventilation b.Its accumulation in the blood is associated with a decrease in pH c.More CO2 dissolves in the blood plasma than is carried in the RBCs d.CO2 concentrations are greater in venous blood than arterial blood.
c. More CO2 dissolves in the blood plasma than is carried in the RBCs
Which of the following counteracts teh movement of bicarbonate ions from the RBC? a.the Bohr effect b.the Haldane effect c.Chloride shifting d.Release of hydrogen ion
c.Chloride shifting
The erythrocyte count increases after a while when an individual goes from a low to a high altitude because the __________.
concentration of oxygen and/or total atmospheric pressure is lower at high altitudes
Select the correct statement about oxygen transport in the blood. a.during normal activity, a molecule of hemoglobin returning to the lungs carries one molecule of O2 b.During conditions of acidosis, hemoglobin is able to carry oxygen more efficiently c.Increased BPG levels in the red blood cells enhance oxygen-carrying capacity d.A 50% oxygen saturation level of blood returning to the lungs might indicate an activity level that is higher than normal
d. A 50% oxygen saturation level of blood returning to the lungs might indicate an activity level that is higher than normal
Which of the following determines lung compliance? a.Airway opening b.Flexibility of the thoracic cage c.muscles of inspiration d.alveolar surface tension
d. alveolar surface tension
Which of the following incorrectly describes mechansims of CO2 transport? a.7-10% of CO2 is dissolved into the plasma b.20% of CO2 is carried in the form of carbaminohemoglobin c.as bicarbonate ion in plasma d.attached to the heme part of hemoglobin
d. attached to the heme part of hemoglobin
Which of the fllowing does NOT influence hemoglobin saturation? a.temperature b.BPG c.carbon dioxide d.nitric oxide
d. nitric oxide
The law of partial pressure is called the ________ law.
dalton's
Which of the disorders below is characterized by destruction of the walls of the alveoli producing abnormally large air spaces that remain filled with air during exhalation?
emphysema
Possible causes of hypoxia include:
too little oxygen in the atmosphere
Changes in arterial pH can modify respiration rate and rhythm even when carbon dioxide and oxygen levels are normal.
true
Strong emotions and pain acting through the limbic system activate sympathetic centers in the hypothalamus, thus modulating respiratory rate and depth by sending signals to the respiratory centers.
true
The local matching of blood flow with ventilation is:
ventilation-perfusion coupling
The lung volume that represents the total volume of exchangeable air is the:
vital capacity
Factors that influence the rate and depth of breathing include:
voluntary cortical control