Which parts of the respiratory system function as the main sites of gas exchange?
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?
Hypoxia can be caused by ______.
hyposecretion of erythropoietin
having a fever
slightly elevated level of lactic acid in the blood
All of the listed responses are correct.
The olfactory mucosal lining of the nasal cavity contains the receptors for the sense of smell.
What is ventilation-perfusion coupling?
matching the amount of oxygen exchanged for carbon dioxide in the
alveoli to the exchange at the tissue level
matching the amount of blood flow through the body to the amount of oxygen in the air sacs
matching the amount of gas reaching the alveoli to the blood flow in pulmonary capillaries
matching the amount of gas reaching the alveoli to pO2 and pCO2 values in the blood
During normal quiet breathing, approximately 750 ml of air moves into and out of the lungs with each breath.
Which of the following provide the greatest surface area for gas exchange?
The __________ is also known as the "guardian of the airways."
Oxygen and carbon dioxide are exchanged in the lungs and through all cell membranes by ________.
What is the most immediate driving force behind pulmonary ventilation?
smooth muscle contraction
air sac contraction
intrapulmonary pressure change
Which of the choices below is not a factor that promotes oxygen binding to and dissociation from hemoglobin?
partial pressure of carbon dioxide
number of red blood cells
partial pressure of oxygen
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
concentration of oxygen and/or total atmospheric pressure is higher at higher altitudes
basal metabolic rate is higher at high altitudes
temperature is lower at higher altitudes
The respiratory membrane is a combination of ________.
respiratory bronchioles and alveolar sacs
alveolar and capillary walls and their fused basement membranes
respiratory bronchioles and alveolar ducts
atria and alveolar sacs
The walls of the alveoli are composed of two types of cells, type I and type II. The function of type II is to ________.
trap dust and other debris
replace mucus in the alveoli
protect the lungs from bacterial invasion
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.
_________, the difference between the intrapulmonary and intrapleural pressures, prevents the lungs from collapsing.
Surfactant helps to prevent the alveoli from collapsing by ________.
protecting the surface of alveoli from dehydration and other
warming the air before it enters
humidifying the air before it enters
interfering with the cohesiveness of water molecules, thereby reducing the surface tension of alveolar fluid
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 does not influence hemoglobin saturation?
Which of the following initiates inspiration?
pontine respiratory centers
ventral respiratory group (VRG)
dorsal respiratory group (DRG)
Which of the choices below determines the direction of respiratory gas movement?
solubility in water
partial pressure gradient
molecular weight and size of the gas molecule
Which of the following pressures rises and falls with the phases of breathing, but eventually equalizes with the atmospheric pressure?
Most inspired particles such as dust fail to reach the lungs because of the ________.
porous structure of turbinate bones
abundant blood supply to nasal mucosa
action of the epiglottis
ciliated mucous lining in the nose
Which volumes are combined to provide the inspiratory capacity?
expiratory reserve volume (ERV) + residual volume (RV)
tidal volume (TV) + inspiratory reserve volume (IRV) + expiratory reserve volume (ERV) + residual volume (RV)
tidal volume (TV) + inspiratory reserve volume (IRV) + expiratory reserve volume (ERV)
tidal volume (TV) + inspiratory reserve volume (IRV)
Which of the following qualifies as a fully saturated hemoglobin molecule?
hemoglobin is transporting three oxygen molecules
hemoglobin is transporting four oxygen molecules
hemoglobin is transporting two oxygen molecules
hemoglobin is transporting one oxygen molecule
Emphysema can result in an ______.
increased level of carbaminohemoglobin
increased level of deoxyhemoglobin
increased likelihood of the skin of Caucasians developing a slightly blue coloration
All of the listed responses are correct.
Possible causes of hypoxia include ________.
getting very cold
taking several rapid deep breaths
obstruction of the esophagus
too little oxygen in the atmosphere
Which muscles are activated during normal quiet inspiration?
diaphragm and internal intercostal muscles
diaphragm and external intercostal muscles
scalenes, sternocleidomastoid, and pectoralis minor muscles
oblique and transversus muscles
Which of the following pressures must remain negative to prevent lung collapse?
The factors responsible for holding the lungs to the thorax wall are ________.
surface tension from pleural fluid and negative pressure in the
the visceral pleurae and the changing volume of the lungs
the smooth muscles of the lung
the diaphragm and the intercostal muscles alone
Which of the following gives the relationship between the pressure and volume of a gas?
Dalton's law of partial pressures
Why is a patient with tuberculosis often noncompliant with treatment?
TB infection causes damage to the nervous system, resulting in
changes in personality and judgment.
Due to the time length of treatment, the patient may stop taking the medication when they start to feel better.
Due to the psychological side effects of the antibiotic used, the patient may stop taking the medication when they start to feel better.
Due to the physiological side effects of the antibiotic used, the patient may stop taking the medication when they start to feel better.
Which center is located in the pons?
pontine respirator group (PRG)
pacemaker neuron center
Intrapleural pressure is normally about 4 mm Hg less than the pressure in the alveoli.
Which of the following is NOT a physical factor that influences pulmonary ventilation?
partial pressure of oxygen in the air
alveolar surface tension
Which of the following is NOT a function of the larynx?
to provide a patent airway
stimulation of the "cough" reflex
to act as a switching mechanism to route air and food into the proper channels
to assist in taste sensation
Tidal volume is air ________.
remaining in the lungs after forced expiration
exchanged during normal breathing
inhaled after normal inspiration
forcibly expelled after normal expiration
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 ductus
Respiratory exchanges are not necessary.
Respiratory exchanges are made through the placenta.
Because the lungs develop later in gestation, fetuses do not need a mechanism for respiratory exchange.
What part of the larynx covers the laryngeal inlet during swallowing to keep food out of the lower respiratory passages?
Which of the following statements is incorrect?
Respiratory rate is lowest in newborn infants.
Descent of the diaphragm results in abdominal breathing.
During fetal life, lungs are filled with fluid.
The chest wall becomes more rigid with age.
What determines the respiratory rhythm in the body?
Hering-Breuer stretch reflexes
medullary respiratory centers
pontine respiratory centers
oxygen levels in the blood
The major nonelastic source of resistance to air flow in the respiratory passageways is ________.