The olfactory mucosal lining of the nasal cavity contains the receptors for the sense of smell.
The functions of the nasal conchae are to enhance the air turbulance in the cavity and to increase the mucosal surface area exposed to the air.
During normal quiet breathing, aproximately 750ml of air moves into and out of the lungs with each breath.
In chronic bronchitis, mucus production is decreased and this leads to the inflammation and fibrosis of the mucosal lining of the bronchial tree.
The largest amount of carbon dioxide is transported in the bloodstream in the form of carbonic anhydrase.
The events of Valsalvaʹs maneuver include closing off the larynx by muscle action (i.e., the rising of the intraabdominal pressure causing holding of the air in the lower respiratory tract).
The Hering-Breuer reflex is a potentially dangerous response that may cause overinflation of the lung.
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.
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).
Daltonʹs 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.
Nasal conchae mainly work on inhalation to warm and moisten air. They serve minor functions for
Air and food are routed into the proper channels by the ________.
The loudness of a person's voice depends on ________.
A) the length of the vocal folds
B) the strength of the intrinsic laryngeal muscles
C) the thickness of vestibular folds
D) 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 ________.
A) to secrete surfactant
B) to protect the lungs from bacterial invasion
C) to replace mucus in the alveoli
D) to trap dust and other debris
After the segmental (tertiary) bronchus, the next smaller branch of the respiratory passageway is (are) the ________.
A) terminal bronchioles
B) respiratory bronchiole
C) alveolar ducts
The smallest macroscopic subdivision of the lung is the ________.
C) primary bronchiole
D) extrinsic ligament
The pleurae are vital to the integrity of the lungs because ________.
A) they contain cilia that protect the lungs
B) they control the volume of the lungs
C) they maintain the proper temperature of the lungs during sleep
D) they produce a lubricating serous secretion, allowing the lungs to glide over the thorax wall during
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
The relationship between the pressure and volume of gases is given by ________.
A) Boyleʹs law
B) Henryʹs law
C) Charlesʹ law
D) Daltonʹs law
The statement, ʺin a mixture of gases, the total pressure is the sum of the individual partial pressures of gases
in the mixtureʺ paraphrases ________.
A) Henryʹs law
B) Boyleʹs law
C) Daltonʹs law
D) Charlesʹ law
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
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
With the Bohr effect, more oxygen is released because ________.
A) a decrease in pH (acidosis) strengthens the hemoglobin-oxygen bond
B) a decrease in pH (acidosis) weakens the hemoglobin-oxygen bond
C) an increase in pH (alkalosis) strengthens the hemoglobin-oxygen bond
D) an increase in pH (alkalosis) weakens the hemoglobin-oxygen bond
The most powerful respiratory stimulus for breathing in a healthy person is ________.
A) loss of oxygen in tissues
B) increase of carbon dioxide
C) pH (acidosis)
D) pH (alkalosis)
Nerve impulses from ________ will result in inspiration.
A) the dorsal respiratory group
B) the chemoreceptor center
C) Brocaʹs center
D) the preoptic nucleus of the hypothalamus
In the plasma, the quantity of oxygen in solution is ________.
A) only about 1.5% of the oxygen carried in dissolved form
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
Which of the following statements is incorrect?
A) During fetal life, lungs are filled with fluid.
B) Respiratory rate is lowest in newborn infants.
C) Descent of the diaphragm results in abdominal breathing.
D) The chest wall becomes more rigid with age.
Another name for the inflation reflex is ________.
D) pulmonary irritant
Which of the following does not influence the increase in ventilation that occurs as exercise is initiated?
A) psychic stimuli
B) decrease in lactic acid levels
D) simultaneous cortical motor activation of the skeletal muscles and respiratory center
Which of the following is not a form of lung cancer?
B) Kaposiʹs sarcoma
C) small cell carcinoma
D) squamous cell carcinoma
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
Which of the following changes occurs as the conducting tubes of the lungs become smaller?
A) Cartilage rings are gradually replaced by regular plates of cartilage.
B) Resistance to air flow decreases due to the increased number of tubes.
C) Smooth muscle amount increases.
D) Lining of the tubes changes from ciliated columnar to simple squamous epithelium which lines the alveoli.
Which of the following does not diminish lung compliance?
A) factors that block the bronchi
B) factors that impair the flexibility of the thoracic cage
C) factors that reduce the natural resilience of the lungs
D) factors that decrease the surface tension of the fluid film of the alveoli
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
The ideal vital capacity of an individual is around ________.
A) 1200 ml
B) 3100 ml
C) 4800 ml
D) 6600 ml
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
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
Since the lungs are filled with fluid during fetal life, which of the following statements is true regarding
A) Respiratory exchanges are made through the ductus arteriosus.
B) Respiratory exchanges are not necessary.
C) Respiratory exchanges are made through the placenta.
D) Since the lungs develop later in gestation, fetuses do not need a mechanism for respiratory exchange.
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) arterial pH resulting from CO2 retention
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
The amount of air that can be inspired above the tidal volume is called ________.
A) reserve air
B) expiratory reserve
C) inspiratory capacity
D) vital capacity
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.
Oxygen and carbon dioxide are exchanged in the lungs and through all cell membranes by ________.
D) active transport
Select the correct statement about the pharynx.
A) The adenoids are 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.
The larynx contains ________.
A) the thyroid cartilage
B) a cricoid cartilage also called the Adamʹs apple
C) an upper pair of avascular mucosal folds called true vocal folds
D) lateral cartilage ridges called false vocal folds
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
The oropharynx does not include ________.
B) palatine tonsils
C) lingual tonsils
D) pharyngeal tonsils
Which of the following is not found on the right lobe of the lung?
A) middle lobe
B) cardiac notch
C) horizontal fissure
D) oblique fissure
Impairments of oxygen transport include ________.
A) anemic hypoxia, usually caused by congestive heart failure
B) carbon monoxide poisoning, a form of hypoxemic hypoxia
C) stagnant hypoxia, due to a functional problem with the lungs
D) hypoxemic hypoxia, resulting from a decrease in levels of functional red blood cells
Which of the following correctly describes mechanisms of CO2 transport?
A) 20% of CO2 is dissolved directly into the plasma.
B) 7-8% of CO2 is carried in the form of carbaminohemoglobin.
C) The chloride shift mechanism enhances CO2 transport.
D) Carbonic anhydrase is responsible for bonding CO2 to hemoglobin.
Factors that influence the rate and depth of breathing include ________.
A) thalamic control
B) voluntary cortical control
C) stretch receptors in the alveoli
D) composition of alveolar gas
Which of the following provide the greatest surface area for gas exchange?
A) alveolar sacs
C) respiratory bronchioles
D) alveolar ducts
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
A gas emboli may occur because ________.
A) a person holds his breath too long
B) a diver holds his breath upon ascent
C) a pilot holds her breath upon descent
D) a person breathes pure oxygen in a pressurized chamber
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
Which center is located in the pons?
A) pontine respirator group (PRG)
D) pacemaker neuron center
The nose serves all the following functions except ________.
A) as a passageway for air movement
B) as the initiator of the cough reflex
C) warming and humidifying the air
D) cleansing the air
A premature baby usually has difficulty breathing. However, the respiratory system is developed enough for
survival by ________.
A) 17 weeks
B) 24 weeks
C) 28 weeks
D) 36 weeks
Which of the following statements is true regarding the respiratory rate of a newborn?
A) The respiratory rate of a newborn is slow.
B) The respiratory rate of a newborn varies between male and female infants.
C) The respiratory rate of a newborn is approximately 30 respirations per minute.
D) 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.
A) The pons is thought to be instrumental in the smooth transition from inspiration to expiration.
B) The ventral respiratory group (expiratory center) 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 dorsal respiratory group (inspiratory center) is contained within the pons.
Which of the following statements is correct?
A) H+ acts directly on central chemoreceptors to decrease the rate and depth of breathing.
B) Low arterial pH is the most powerful stimulator of respiration.
C) Arterial pH does not affect central chemoreceptors directly.
D) H+ has little effect on the blood pH.
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, negative pressure, and atmospheric pressure on the thorax
The erythrocyte count increases after a while when an individual goes from a low to a high altitude because ________.
A) the temperature is lower at higher altitudes
B) the basal metabolic rate is higher at high altitudes
C) the concentration of oxygen and/or total atmospheric pressure is higher at higher altitudes
D) the concentration of oxygen and/or total atmospheric pressure is lower at high altitudes
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
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.
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.
Select the correct statement about oxygen transport in blood ________.
A) During normal activity, a molecule of hemoglobin returning to the lungs contains 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