c. active transport
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.
a. external respiration
b. pulmonary ventilation
c. blood pH adjustment
d. internal respiration
a. Charles’ law
b. Henry’s law
c. Dalton’s law
d. Boyle’s law
a. expiratory reserve volume
b. tidal volume
c. vital capacity
d. inspiratory capacity
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
a. pseudostratified ciliated epithelium
b. surface tension of water
d. cartilage rings
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.
a. the temperature
b. solubility in water
c. molecular weight and size of the gas molecule
d. partial pressure gradient
c. nitric oxide
d. carbon dioxide
a. alveolar surface tension
b. airway opening
c. muscles of inspiration
d. flexibility of the thoracic cage
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. 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. inspiratory reserve
b. vital capacity
c. reserve air
d. expiratory reserve
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. 24 weeks
b. 28 weeks
c. 17 weeks
d. 36 weeks
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.
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
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.
stretch receptors in the alveoli
voluntary cortical control
composition of alveolar air
ciliated mucous lining in the nose
porous structure of turbinate bones
action of the epiglottis
abundant blood supply to nasal mucosa
increase of carbon dioxide
loss of oxygen in tissues
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
midbrain and medulla
pons and midbrain
medulla and pons
upper spinal cord and medulla
remaining in the lungs after forced expiration
forcibly expelled after normal expiration
inhaled after normal inspiration
exchanged during normal breathing
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.
pacemaker neuron center
pontine respirator group (PRG)
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.
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
rising carbon dioxide levels
arterial Po2 below 60 mm Hg
rising blood pressure
arterial pH resulting from CO2 retention
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
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
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
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.
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
as a passageway for air movement
warming and humidifying the air
as the initiator of the cough reflex
cleansing the air
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.
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
number of red blood cells
partial pressure of oxygen
partial pressure of carbon dioxide
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
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
decrease in lactic acid levels
simultaneous cortical motor activation of the skeletal muscles and respiratory center
transport of respiratory gases