Chapter 22 : The Respiratory System

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 ion to be generated (the Bohr effect).

False

During normal quiet breathing, approximately 750 ml of air moves into and out of the lungs with each breath.

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

Oxygenated hemoglobin releases oxygen more readily when the pH is more basic.

False

The Hering-Breuer reflex is a potentially dangerous response that may cause overinflation of the lung.

False

The average individual has 500 ml of residual volume in his lungs.

False

The largest amount of carbon dioxide is transported in the bloodstream in the form of carbonic anhydrase.

False

Which of the following statements is true regarding the respiratory rate of a newborn? The respiratory rate of a newborn is slow. The respiratory rate of a newborn is, at its highest rate, approximately 40-80 respirations per minute. The respiratory rate of a newborn is approximately 30 respirations per minute. The respiratory rate of a newborn varies between male and female infants.

The respiratory rate of a newborn is, at its highest rate, approximately 40-80 respirations per minute.

Atelectasis (lung collapse) renders the lung useless for ventilation.

True

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 the mixture.

True

Labored breathing is termed dyspnea.

True

Smoking diminishes ciliary action and eventually destroys the cilia.

True

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.

True

The olfactory mucosal lining of the nasal cavity contains the receptors for the sense of smell.

True

Ventilation perfusion coupling means that more blood flows past functional alveoli than past nonfunctional alveoli.

True

Tidal volume is air ________. remaining in the lungs after forced expiration forcibly expelled after normal expiration inhaled after normal inspiration exchanged during normal breathing

exchanged during normal breathing

The most powerful respiratory stimulus for breathing in a healthy person is ________. increase of carbon dioxide pH (alkalosis) pH (acidosis) loss of oxygen in tissues

increase of carbon dioxide

Surfactant helps to prevent the alveoli from collapsing by ________. warming the air before it enters interfering with the cohesiveness of water molecules, thereby reducing the surface tension of alveolar fluid protecting the surface of alveoli from dehydration and other environmental variations humidifying the air before it enters

interfering with the cohesiveness of water molecules, thereby reducing the surface tension of alveolar fluid

Which respiratory-associated muscles would contract if you were to blow up a balloon? diaphragm would contract, external intercostals would relax diaphragm contracts, internal intercostals would relax internal intercostals and abdominal muscles would contract external intercostals would contract and diaphragm would relax

internal intercostals and abdominal muscles would contract

Respiratory control centers are located in the ________. midbrain and medulla pons and midbrain medulla and pons upper spinal cord and medulla

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 partial pressure of oxygen partial pressure of carbon dioxide temperature

number of red blood cells

In the plasma, the quantity of oxygen in solution is ________. greater than the oxygen combined with hemoglobin only about 1.5% of the oxygen carried in dissolved form not present except where it is combined with carrier molecules about equal to the oxygen combined with hemoglobin

only about 1.5% of the oxygen carried in dissolved form

Which center is located in the pons? expiratory inspiratory pacemaker neuron center pontine respirator group (PRG)

pontine respirator group (PRG)

Which of the choices below is not a functional process performed by the respiratory system? transport of respiratory gases external respiration pulmonary respiration pulmonary ventilation

pulmonary ventilation

Which of the following is not a stimulus for breathing? rising carbon dioxide levels arterial Po2 below 60 mm Hg rising blood pressure arterial pH resulting from CO2 retention

rising blood pressure

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 compliance and transpulmonary pressures compliance and the surface tension of the alveolar fluid the natural tendency for the lungs to recoil and transpulmonary pressures

the natural tendency for the lungs to recoil and the surface tension of the alveolar fluid

For gas exchange to be efficient, the respiratory membrane must be ________. 0.5 to 1 micrometer thick at least 3 micrometers thick between 5 and 6 micrometers thick The thickness of the respiratory membrane is not important in the efficiency of gas exchange.

0.5 to 1 micrometer thick

Select the correct statement about oxygen transport in blood: During conditions of acidosis, hemoglobin is able to carry oxygen more efficiently. A 50% oxygen saturation level of blood returning to the lungs might indicate an activity level higher than normal. During normal activity, a molecule of hemoglobin returning to the lungs carries one molecule of O2. Increased BPG levels in the red blood cells enhance oxygen-carrying capacity.

A 50% oxygen saturation level of blood returning to the lungs might indicate an activity level higher than normal.

Because the lungs are filled with fluid during fetal life, which of the following statements is true regarding respiratory exchange? a. Respiratory exchanges are made through the ductus arteriosus. b. Respiratory exchanges are made through the placenta. c. Because the lungs develop later in gestation, fetuses do not need a mechanism for respiratory exchange. d. Respiratory exchanges are not necessary.

B. Respiratory exchanges are made through the placenta.

The relationship between the pressure and volume of gases is given by ________. Charles' law Dalton's law Henry's law Boyle's law

Boyle's law

The respiratory membrane is a combination of ________. A. respiratory bronchioles and alveolar ducts B. respiratory bronchioles and alveolar sacs C. atria and alveolar sacs D. alveolar and capillary walls and their fused basement membranes

D. alveolar and capillary walls and their fused basement membranes

Which statement about CO2 is incorrect? More CO2 dissolves in the blood plasma than is carried in the RBCs. Its accumulation in the blood is associated with a decrease in pH. CO2 concentrations are greater in venous blood than arterial blood. Its concentration in the blood is decreased by hyperventilation.

More CO2 dissolves in the blood plasma than is carried in the RBCs.

Which of the following is not true of the respiratory tract from the medium bronchi to the aveoli? Cartilage gradually decreases and disappears at the bronchioles. Lining of the tubes changes from ciliated columnar to simple squamous epithelium in the alveoli. Proportionally, smooth muscle decreases uniformly. Resistance to air flow increases due to the increase in cross-sectional diameter.

Resistance to air flow increases due to the increase in cross-sectional diameter.

Select the correct statement about the physical factors influencing pulmonary ventilation. a. As alveolar surface tension increases, additional muscle action will be required. b. Surfactant helps increase alveolar surface tension. c. A decrease in compliance causes an increase in ventilation. d. A lung that is less elastic will require less muscle action to perform adequate ventilation.

a. As alveolar surface tension increases, additional muscle action will be required.

Which of the following determines lung compliance? a. alveolar surface tension b. airway opening c. muscles of inspiration d. flexibility of the thoracic cage

a. alveolar surface tension

With the Bohr effect, more oxygen is released because a(n) ________. a. decrease in pH (acidosis) weakens the hemoglobin-oxygen bond b. decrease in pH (acidosis) strengthens the hemoglobin-oxygen bond c. increase in pH (alkalosis) weakens the hemoglobin-oxygen bond d. increase in pH (alkalosis) strengthens the hemoglobin-oxygen bond

a. decrease in pH (acidosis) weakens the hemoglobin-oxygen bond

Oxygen and carbon dioxide are exchanged in the lungs and through all cell membranes by ________. a. diffusion b. filtration c. active transport d. osmosis

a. diffusion

The amount of air that can be inspired above the tidal volume is called ________. a. inspiratory reserve b. vital capacity c. reserve air d. expiratory reserve

a. inspiratory reserve

The larynx contains ________. a. the thyroid cartilage b. lateral cartilage ridges called false vocal folds c. an upper pair of avascular mucosal folds called true vocal folds d. a cricoid cartilage also called the Adam's apple

a. the thyroid cartilage

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 helps divide the thoracic cavity into three chambers allows the lungs to inflate and deflate without friction helps limit the spread of local infections

aids in blood flow to and from the heart because the heart sits between the lungs

Which of the following provide the greatest surface area for gas exchange? respiratory bronchioles alveolar sacs alveoli alveolar ducts

alveoli

How is the bulk of carbon dioxide carried in blood? chemically combined with the heme portion of hemoglobin chemically combined with the amino acids of hemoglobin as carbaminohemoglobin in the red blood cells as the bicarbonate ion in the plasma after first entering the red blood cells as carbonic acid in the plasma

as the bicarbonate ion in the plasma after first entering the red blood cells

The nose serves all the following functions except ________. as a passageway for air movement warming and humidifying the air as the initiator of the cough reflex cleansing the air

as the initiator of the cough reflex

Which of the following correctly describes mechanisms of CO2 transport? as bicarbonate ion in plasma attached to the heme part of hemoglobin 7 10% of CO2 is dissolved directly into the plasma 20% of CO2 is carried in the form of carbaminohemoglobin

attached to the heme part of hemoglobin

A premature baby usually has difficulty breathing. However, the respiratory system is developed enough for survival by ________. a. 24 weeks b. 28 weeks c. 17 weeks d. 36 weeks

b. 28 weeks

The factors responsible for holding the lungs to the thorax wall are ________. a. the diaphragm and the intercostal muscles alone b. surface tension from pleural fluid and negative pressure in the pleural cavity c. the visceral pleurae and the changing volume of the lungs d. the smooth muscles of the lung

b. surface tension from pleural fluid and negative pressure in the pleural cavity

The statement, "in a mixture of gases, the total pressure is the sum of the individual partial pressures of gases in the mixture" paraphrases ________. a. Charles' law b. Henry's law c. Dalton's law d. Boyle's law

c. Dalton's law

Which of the following is not an event necessary to supply the body with O2 and dispose of CO2? a. external respiration b. pulmonary ventilation c. blood pH adjustment d. internal respiration

c. blood pH adjustment

The lung volume that represents the total volume of exchangeable air is the ________. a. expiratory reserve volume b. tidal volume c. vital capacity d. inspiratory capacity

c. vital capacity

Most inspired particles such as dust fail to reach the lungs because of the ________. ciliated mucous lining in the nose porous structure of turbinate bones action of the epiglottis abundant blood supply to nasal mucosa

ciliated mucous lining in the nose

The erythrocyte count increases after a while when an individual goes from a low to a high altitude because the ________. temperature is lower at higher altitudes concentration of oxygen and/or total atmospheric pressure is lower at high altitudes basal metabolic rate is higher at high altitudes concentration of oxygen and/or total atmospheric pressure is higher at higher altitudes

concentration of oxygen and/or total atmospheric pressure is lower at high altitudes

Which of the following statements is incorrect? a. The chest wall becomes more rigid with age. b. During fetal life, lungs are filled with fluid. c. Descent of the diaphragm results in abdominal breathing. d. Respiratory rate is lowest in newborn infants.

d. Respiratory rate is lowest in newborn infants.

Which of the following maintains the patency (openness) of the trachea? a. pseudostratified ciliated epithelium b. surface tension of water c. surfactant d. cartilage rings

d. cartilage rings

Complete the following statement using the choices below. Air moves out of the lungs when the pressure inside the lungs is _________. a. equal to the pressure in the atmosphere. b. greater than the intra-alveolar pressure. c. less than the pressure in the atmosphere. d. greater than the pressure in the atmosphere.

d. greater than the pressure in the atmosphere.

Which of the following does not influence hemoglobin saturation? a. temperature b. DPG c. nitric oxide d. carbon dioxide

d. nitric oxide

Which of the choices below determines the direction of respiratory gas movement? a. the temperature b. solubility in water c. molecular weight and size of the gas molecule d. partial pressure gradient

d. partial pressure gradient

Which of the following does not influence the increase in ventilation that occurs as exercise is initiated? proprioceptors psychic stimuli decrease in lactic acid levels simultaneous cortical motor activation of the skeletal muscles and respiratory center

decrease in lactic acid levels

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? combined amount of CO2 in the blood and air in the alveoli the expansion of respiratory muscles that were contracted during inspiration and the lack of surface tension on the alveolar wall the negative feedback of expansion fibers used during inspiration and the outward pull of surface tension due to surfactant 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 recoil of elastic fibers that were stretched during inspiration and the inward pull of surface tension due to the film of alveolar fluid

Factors that influence the rate and depth of breathing include ________. stretch receptors in the alveoli voluntary cortical control thalamic control composition of alveolar air

voluntary cortical control