Respiratory System-Ch.21

Type II alveolar cells secrete

surfactant

The relationship between gas pressure and gas volume is described by ________. A) Boyle's law B) Henry's law C) Charles' law D) Dalton's law

A) Boyle's law

Select the correct statement about the neural 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 breathing. C) The pontine respirator group (PRG) continuously stimulates the medulla to provide inspiratory drive. D) The ventral respiratory group is contained within the pons

A) The pons is thought to be instrumental in the smooth transition from inspiration to expiration.

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

A) ciliated mucous lining in the nose

In the plasma, the quantity of oxygen in solution is ________. A) only about 1.5% of the oxygen carried in blood B) about equal to the oxygen combined with hemoglobin C) greater than the oxygen combined with hemoglobin D) not present except where it is combined with carrier molecules

A) only about 1.5% of the oxygen carried in blood

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

A) pontine respirator group (PRG)

The walls of the alveoli are composed of two types of cells, type I and type II. The function of type II is to ________. A) secrete surfactant B) trap dust and other debris C) replace mucus in the alveoli D) protect the lungs from bacterial invasion

A) secrete surfactant

Which of the choices below describes the forces that act to pull the lungs away from the thorax wall and thus collapse the lungs? A) the natural tendency for the lungs to recoil and the surface tension of the alveolar fluid B) compliance and transpulmonary pressures C) the natural tendency for the lungs to recoil and transpulmonary pressures D) compliance and the surface tension of the alveolar fluid

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

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

A) the recoil of elastic fibers that were stretched during inspiration and the inward pull of surface tension due to the film of alveolar fluid

Inspiratory capacity is ________. A) the total amount of air that can be inspired after a tidal expiration B) the total amount of exchangeable air C) functional residual capacity D) air inspired after a tidal inhalation

A) the total amount of air that can be inspired after a tidal expiration

Possible causes of hypoxia include ________. A) too little oxygen in the atmosphere B) obstruction of the esophagus C) taking several rapid deep breaths D) getting very cold

A) too little oxygen in the atmosphere

Terminates in alveoli

Alveolar duct

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

B) 0.5 to 1 micrometer thick

18) 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 a

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.

Select the correct statement about the pharynx. A) The pharyngeal tonsil is located in the laryngopharynx. B) The auditory tube drains into the nasopharynx. C) The laryngopharynx blends posteriorly into the nasopharynx. D) The palatine tonsils are embedded in the lateral walls of the nasopharynx

B) The auditory tube drains into the nasopharynx.

The larynx contains ________. A) the thyroid cartilage B) a cricoid cartilage also called the Adam's apple C) an upper pair of avascular mucosal folds called true vocal folds D) lateral cartilage ridges called false vocal folds

B) a cricoid cartilage also called the Adam's apple

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

B) alveolar and capillary walls and their fused basement membranes

The main site of gas exchange is the ________. A) alveolar sacs B) alveoli C) alveolar duct D) respiratory bronchiole

B) alveoli

Which of the following provide the greatest surface area for gas exchange? A) alveolar sacs B) alveoli C) respiratory bronchioles D) alveolar ducts

B) alveoli

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

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

The nose serves all the 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

Which of the following is not an event necessary to supply the body with O2 and dispose of CO2? A) pulmonary ventilation B) blood pH adjustment C) internal respiration D) external respiration

B) blood pH adjustment

) With the Bohr effect, more oxygen is released because a(n) ________. A) decrease in pH (acidosis) strengthens the hemoglobin-oxygen bond B) decrease in pH (acidosis) weakens the hemoglobin-oxygen bond C) increase in pH (alkalosis) strengthens the hemoglobin-oxygen bond D) increase in pH (alkalosis) weakens the hemoglobin-oxygen bond

B) 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) osmosis B) diffusion C) filtration D) active transport

B) diffusion

Gas emboli may occur because a ________. A) person holds his breath too long B) diver holds his breath upon ascent C) pilot holds her breath upon descent D) person breathes pure oxygen in a pressurized chamber

B) diver holds his breath upon ascent

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

B) exchanged during normal breathing

Complete the following statement using the choices below. Air moves out of the lungs when the pressure inside the lungs is ________. A) less than the pressure in the atmosphere B) greater than the pressure in the atmosphere C) equal to the pressure in the atmosphere D) greater than the intra-alveolar pressure

B) greater than the pressure in the atmosphere

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

B) increase of carbon dioxide

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

B) internal intercostals and abdominal muscles would contract

Respiratory control centers are located in the ________. A) midbrain and medulla B) medulla and pons C) pons and midbrain D) upper spinal cord and medulla

B) medulla and pons

Which of the choices below determines the direction of respiratory gas movement? A) solubility in water B) partial pressure gradient C) the temperature D) molecular weight and size of the gas molecule

B) partial pressure gradient

Intrapulmonary pressure is the ________. A) pressure within the pleural cavity B) pressure within the alveoli of the lungs C) negative pressure in the intrapleural space D) difference between atmospheric pressure and respiratory pressure

B) pressure within the alveoli of the lungs

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

The lung volume that represents the total volume of exchangeable air is the ________. A) tidal volume B) vital capacity C) inspiratory capacity D) expiratory reserve volume

B) vital capacity

37) Factors that influence the rate and depth of breathing include ________. A) thalamic control B) voluntary cortical control C) stretch receptors in the alveoli D) temperature of alveolar air

B) voluntary cortical control

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 of the following maintains the patency (openness) of the trachea? A) surface tension of water B) surfactant production C) C-shaped cartilage rings D) pseudostratified ciliated epithelium

C) C-shaped cartilage rings

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) Henry's law B) Boyle's law C) Dalton's law D) Charles' law

C) Dalton's law

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 the 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

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? A) pneumonia B) tuberculosis C) emphysema D) coryza

C) emphysema

The major nonelastic source of resistance to air flow in the respiratory passageways is ________. A) surfactant B) surface tension C) friction D) air pressure

C) friction

The amount of air that can be inspired above the tidal volume is called ________. A) reserve air B) expiratory capacity C) inspiratory reserve D) vital capacity

C) inspiratory reserve

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

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

Select the correct statement about oxygen transport in 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 higher than normal.

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

Which of the choices below is not a role of the pleura? A) allows the lungs to inflate and deflate without friction B) helps divide the thoracic cavity into three chambers C) helps limit the spread of local infections D) aids in blood flow to and from the heart because the heart sits between the lungs

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

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 mechanisms of CO2 transport? A) 7-10% of CO2 is dissolved directly 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

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

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

The loudness of a person's voice depends on the ________. A) thickness of vestibular folds B) length of the vocal folds C) strength of the intrinsic laryngeal muscles D) force with which air rushes across the vocal folds

D) force with which air rushes across the vocal folds

Which of the following does not influence hemoglobin saturation? A) temperature B) BPG C) carbon dioxide D) nitric oxide

D) nitric oxide

Which of the choices below is not a factor that promotes oxygen binding to and dissociation from hemoglobin? A) partial pressure of oxygen B) temperature C) partial pressure of carbon dioxide D) number of red blood cells

D) number of red blood cells

The factors responsible for holding the lungs to the thorax wall are ________. A) the smooth muscles of the lung B) the diaphragm and the intercostal muscles alone C) the visceral pleurae and the changing volume of the lungs D) surface tension from pleural fluid and negative pressure in the pleural cavity

D) surface tension from pleural fluid and negative pressure in the pleural cavity

The local matching of blood flow with ventilation is ________. A) the Bohr effect B) the Haldane effect C) chloride shifting D) ventilation-perfusion coupling

D) ventilation-perfusion coupling

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

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

Nasal conchae mainly work on inhalation to warm and moisten air. They serve minor functions for exhalation

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

The paired lungs occupy all of the thoracic cavity

False

Where the respiratory zone of the lungs begins

Respiratory Bronchioles

No exchange of gases occurs here

Segmental Bronchi

Atelectasis (lung collapse) renders the lung useless for ventilation

True

Changes in arterial pH can modify respiration rate and rhythm even when carbon dioxide and oxygen levels are normal.

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

Intrapleural pressure is normally about 4 mm Hg less than the pressure in the alveoli.

True

Labored breathing is termed dyspnea

True

Smoking diminishes ciliary action and eventually destroys the cilia

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 alveolar ventilation rate is the best index of effective ventilation

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 lungs are perfused by two circulations: the pulmonary and the bronchial. The pulmonary circulation is for oxygenation of blood. The bronchial circulation supplies blood to the lung structures (tissue).

True

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

True

The parietal pleura lines the thoracic wall

True

Tracheal obstruction is life threatening

True

Under certain conditions, the vocal folds act as a sphincter that prevents air passage.

True

Valsalva's maneuver involves closing off the glottis (preventing expiration) while contracting the muscles of expiration, causing an increase in intra-abdominal pressure

True

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

True

Composed of cuboidal cells

Type II cells

Secrete a fluid containing surfactant

Type II cells

Terminal bronchioles are lined with ________ epithelium.

cuboidal