Download Respiratory System: Anatomy, Physiology, and Gas Exchange - Questions and Answers and more Exams Nursing in PDF only on Docsity!
AACN CRITICAL CARE NURSING EXAM 2025 WITH
100% CORRECT ANSWERS/A+ GRADE
Cellular respiration cannot be directly measured but is estimated by the amount of
- CORRECT ANSWER CO2 produced (V
C O2 ) and the amount of O
consumed (V
O 2 ).
V
C O 2 - CORRECT ANSWER CO 2 produced in celluar respiration
V
O 2 - CORRECT ANSWER the amount of O 2 consumed in cellular respiration
external respiration - CORRECT ANSWER The Exchange of O2 and
CO2 at the alveolar-capillary level. It is the ratio of the CO2 produced to the
O2 taken up per minute.
V
CO2/min : V
O 2 /min
Proper functioning of the respiratory circuit requires efficient interaction of the - 1.
CORRECT ANSWER respiratory
- circulatory
- neuromuscular systems.
In addition to its primary function of O2 and CO2 exchange, the lung also carries
out metabolic and endocrine functions as a source of hormones and a site of
hormone metabolism.
In addition, the lung is a target of hormonal actions by other endocrine organs -
correct answer (e.g., surfactant production and potentially activation of bradykinin).
Anatomic divisions of Lungs:
Right lung:
Left Lung: - CORRECT ANSWER Right Lung: 3 lobes—upper, middle, lower
Left lung (two lobes—upper, lower).
Lobes are divided into bronchopulmonary segments - 10 -
CORRECT ANSWER RIGHT 9 - LEFT
Bronchopulmonary segments are subdivided into
CORRECT ANSWER secondary lobules
Secondary Lobules –
CORRECT ANSWER Independent respiratory units of lung
each bronchopulmonary segment is supplied independently
by:
a (tertiary) segmental bronchus
a tertiary branch of pulmonary artery - carry low oxygen ("venous") blood to
lungs for oxygenation
a branch of bronchial artery
What does a a tertiary branch of pulmonary artery do for secondary lobules? - -
CORRECT ANSWER carries low oxygen ("venous") blood to lungs for
oxygenation
Smallest gross anatomic units of lung tissue; contain the primary functional units of
the lung - CORRECT ANSWER Lobule:
- Filters by trapping particles larger than 6 μm in diameter
Separation of food from air is controlled by - CORRECT ANSWER a) local nerve
reflexes
b) Opening of eustachian tube regulates middle ear pressure
c) Lymphatic tissues control infection
Larynx:
a) Vocal cords: Speech function - CORRECT ANSWER Complex structure
consisting of incomplete rings of cartilage and numerous muscles and ligaments
Contraction of muscles of the larynx causes the vocal cords to change shape.
Vibration of the vocal cords produces sound. Speech is a joint function of the
vocal cords, lips, tongue, soft palate, and respiration with control by temporal and
parietal lobes of the cerebral cortex.
- Glottis: Opening between the vocal cords - CORRECT ANSWER b) Valve
action by the epiglottis helps to prevent aspiration.
c) Cough reflex: Cords close resulting in intrathoracic pressure increases to permit
coughing or Valsalva maneuver.
Cricoid cartilage CORRECT ANSWER 1) Only complete cartilage ring
Narrowest part of the child's airway
Inner diameter sets the limit for the size of an endotracheal tube passed through
the larynx
Trachea: - CORRECT ANSWER Tubular structure consisting of 16 to 20
incomplete, or C-shaped, cartilaginous rings that stabilize the airway and
prevent complete collapse with coughing
Trachea - CORRECT ANSWER a) Begins the tracheobronchial tree
b) Warms and humidifies air
c) Mucosal cells trap foreign material
d) Cilia propel mucus upward through the airway
e) Cough reflex present especially at the point of tracheal bifurcation (carina)
f) Smooth muscle innervated by the parasympathetic branch of the autonomic
nervous system
g) Carina—the point at which the trachea divides to form the mainstem bronchi
Cough reflex present especially at - correct answer the point of tracheal bifurcation
(carina)
Right mainstem bronchus is and than the left - correct answer shorter and
wider
Terminal bronchioles - correct answer a) Smooth muscle walls (no cartilage);
bronchospasm may narrow the lumen and increase airway resistance
b) Ciliated mucosal cells become flattened with progressive loss of cilia toward the
alveoli
c) Sensitive to CO2 levels: Increased levels induce bronchiolar dilation,
decreased levels induce constriction
In the terminal bronchioles, increased CO2 level - correct answer induce
bronchiolar dilation
In the terminal bronchioles, decreased CO2 levels - correct answer induce
constriction
Pulmonary Surfactant Enables surface tension to decrease as - correct
answer alveolar volume decreases during expiration, which prevents
alveolar collapse
Decreases the work of breathing, permits the alveoli to remain inflated at low
distending pressures, reduces net forces causing tissue fluid accumulation -
correct answer Pulmonary Surfactant
Reduction in surfactant production makes - correct answer lung expansion more
difficult; the greater the surface tension, the greater the pressure needed to
overcome it
Detoxifies inhaled gases and traps inhaled and deposited particles - correct answer
Surfactant
Alveolar-capillary membrane - correct answer 1. alveolar epithelium
- interstitial space
- capillary endothelium
Gas exchange pathway: - correct answer Alveolar epithelium → alveolar basement
membrane → interstitial space → capillary basement membrane → capillary
endothelium → plasma → erythrocyte membrane → erythrocyte cytoplasm
Alveolar ventilation ( V
A ) : That part of total ventilation taking part in gas
exchange and, therefore, the only part useful to the body - correct answer (a)
Alveolar ventilation is one component of minute ventilation
Minute ventilation ( V
E ) : - correct answer Amount of air exhaled in 1 minute.
Equal to exhaled tidal volume (VT) multiplied by respiratory rate (RR or f). -
correct answer Minute Ventilation (VE)
Normal resting minute ventilation in an adult is about - correct answer 6 L/min:
VT - correct answer Exhaled Tidal Volume
VT * RR = VE - correct answer Exhaled Tidal Vol (VT) * Resp Rate (RR) =
Minute Ventilation (VE)
Tidal volume is easily measured at the bedside by hand-held devices or a
mechanical ventilator. - correct answer spirometers (measure tidal vol)
Exhaled minute ventilation is a routinely measured parameter for patients on
ventilators. Minute ventilation is composed of both - correct answer 1.
alveolar ventilation ( V
A )
- physiologic dead-space ventilation ( V
D ) :
alveolar ventilation - correct answer ( V
A )
physiologic dead-space ventilation - correct answer ( V
D ) :
VE = VA + VD - correct answer Minute Vnetilation = aveloar ventilation +
physiologic dead-space ventilation
manometer in respiratory therapy measures - correct answer pressure of expired air
If PaCO2 is high, alveolar ventilation is low and - correct answer hypoventilation is
present
often leads to ventilator dependency. - correct answer Injury at or above C3 to C
level
