S1 L3.1: Functional Anatomy of the Lungs Flashcards
Composed of 12 ribs, thoracic vertebrae and sternum
Thoracic Cage
T/F: Ribs are inclined superiorly
False
Inclined inferiorly
What are the inspiratory muscles?
Diaphragm, SCM,
& scalenes
What are the expiratory muscles?
Abdominal muscles, internal intercostals
AIRWAYS: Anatomical Division
Nose, nasopharynx, larynx
Upper Airway
AIRWAYS: Anatomical Division
In the conducting zone, which generation is devoid of alveoli?
1-16th Generation
AIRWAYS: Anatomical Division
In the conducting zone, that is the generation with large or central airways?
1st-9th Generation
AIRWAYS: Anatomical Division
In the conducting zone, which generations have smal or peripheral airways?
10-16th Generation
AIRWAYS: Anatomical Division
Which generation has alveolar structure?
17th-23rd Generation
Also known as the Respiratory Zone
Statement 1: The anatomical dead space is the part where airways are devoid of alveoli.
Statement 2: These areas include the upper airways and the conducting zone
a. TF
b. FT
c. TT
d. FF
c. TT
No respiration occurs here
AIRWAYS: Histology
With mucosa and smooth muscle, no cartilage
Small or peripheral airways <1mm in diameter
Bronchioles
AIRWAYS: Histology
With mucosa, smooth
muscles, cartilage
Large or central airways >1mm in diameter
Bronchus
Lung Parenchyma
Structures distal to the terminal bronchioles
Respiratory Unit
Lung Parenchyma
Respiratory Organization
Respiratory unit → [?] → segments → [?] → lungs
Respiratory unit → Lobules → segments → Lobes → lungs
Blood Supply
Statement 1: The respiratory unit is supplied by the bronchial arteries
Statement 2: The conducting zone is supplied by pulmonary arteries
a. TF
b. FT
c. TT
d. FF
d. FF
Respiratory Unit: Pulmonary Arteries
Conducting Zone: Bronchial Arteries
Epithelial cells that line the peripheral gas exchange region of the lungs.
Pneumocytes
Comprise only 4% of the alveolar surface area but constitute 60% of alveolar epithelial cells and 10-15% of all lung cells
a. Type I (Flat) Pneumocyte
b. Type II (Cuboidal) Pneumocyte
b. Type II (Cuboidal) Pneumocyte
These cover more than 97% of the alveolar surface.
a. Type I (Flat) Pneumocyte
b. Type II (Cuboidal) Pneumocyte
a. Type I (Flat) Pneumocyte
Modulate the fluid composition surrounding the alveolar epithelium
a. Type I (Flat) Pneumocyte
b. Type II (Cuboidal) Pneumocyte
b. Type II (Cuboidal) Pneumocyte
Store lung surfactant intracellularly in organelles known as lamellar bodies
a. Type I (Flat) Pneumocyte
b. Type II (Cuboidal) Pneumocyte
b. Type II (Cuboidal) Pneumocyte
Complex branched cells with multiple cytoplasmic plates that represent the gas exchange surface in the alveolus of the lung
a. Type I (Flat) Pneumocyte
b. Type II (Cuboidal) Pneumocyte
a. Type I (Flat) Pneumocyte
Important Landmarks
Lung Apex
Protrudes 3-4 cm above the first rib anteriorly; same level posteriorly
Important Landmarks
Oblique Fissure
4th thoracic vertebra posteriorly to 6th chondrosternal junction; follows slope of 4th rib crossing the 5th rib.
Important Landmarks
Horizontal Fissure
4th rib parasternally extending laterally to meet the oblique fissure
Important Landmarks
Trachea
From C6 to T6-T7
Volumes and Ventilation
a. Tidal Volume
b. Inspiratory Reserve Volume (IRV)
c. Expiratory Reserve Volume (ERV)
d. Residual Volume (RV)
e. Vital Capacity (VC)
d. Inspiratory Capacity (IC)
f. Functional Residual Capacity (FRC)
g. Total Lung Capacity (TLC)
Maximum amount of air that can be inhaled from the end of a tidal volume
d. Inspiratory Capacity (IC)
Volumes and Ventilation
a. Tidal Volume
b. Inspiratory Reserve Volume (IRV)
c. Expiratory Reserve Volume (ERV)
d. Residual Volume (RV)
e. Vital Capacity (VC)
d. Inspiratory Capacity (IC)
f. Functional Residual Capacity (FRC)
g. Total Lung Capacity (TLC)
Volume of air remaining in the lungs at the end of maximum expiration
d. Residual Volume (RV)
Volumes and Ventilation
a. Tidal Volume
b. Inspiratory Reserve Volume (IRV)
c. Expiratory Reserve Volume (ERV)
d. Residual Volume (RV)
e. Vital Capacity (VC)
d. Inspiratory Capacity (IC)
f. Functional Residual Capacity (FRC)
g. Total Lung Capacity (TLC)
The maximum amount of air that can be inhaled after a normal tidal volume inspiration
b. Inspiratory Reserve Volume (IRV)
Volumes and Ventilation
a. Tidal Volume
b. Inspiratory Reserve Volume (IRV)
c. Expiratory Reserve Volume (ERV)
d. Residual Volume (RV)
e. Vital Capacity (VC)
d. Inspiratory Capacity (IC)
f. Functional Residual Capacity (FRC)
g. Total Lung Capacity (TLC)
Volume of air remaining in the lungs at the end of a TV expiration
f. Functional Residual Capacity (FRC)
Volumes and Ventilation
a. Tidal Volume
b. Inspiratory Reserve Volume (IRV)
c. Expiratory Reserve Volume (ERV)
d. Residual Volume (RV)
e. Vital Capacity (VC)
d. Inspiratory Capacity (IC)
f. Functional Residual Capacity (FRC)
g. Total Lung Capacity (TLC)
Volume of air that can be exhaled from the lungs after a maximum inspiration
e. Vital Capacity (VC)
Volumes and Ventilation
a. Tidal Volume
b. Inspiratory Reserve Volume (IRV)
c. Expiratory Reserve Volume (ERV)
d. Residual Volume (RV)
e. Vital Capacity (VC)
d. Inspiratory Capacity (IC)
f. Functional Residual Capacity (FRC)
g. Total Lung Capacity (TLC)
Volume of air in the lungs after a maximum inspiration
g. Total Lung Capacity (TLC)
Volumes and Ventilation
a. Tidal Volume
b. Inspiratory Reserve Volume (IRV)
c. Expiratory Reserve Volume (ERV)
d. Residual Volume (RV)
e. Vital Capacity (VC)
d. Inspiratory Capacity (IC)
f. Functional Residual Capacity (FRC)
g. Total Lung Capacity (TLC)
Volume of air inspired and expired during normal quiet breathing
a. Tidal Volume
Volumes and Ventilation
a. Tidal Volume
b. Inspiratory Reserve Volume (IRV)
c. Expiratory Reserve Volume (ERV)
d. Residual Volume (RV)
e. Vital Capacity (VC)
d. Inspiratory Capacity (IC)
f. Functional Residual Capacity (FRC)
g. Total Lung Capacity (TLC)
The maximum amount of air that can be exhaled from the resting expiratory level
c. Expiratory Reserve Volume (ERV)
Volumes and Ventilation
a. Tidal Volume
b. Inspiratory Reserve Volume (IRV)
c. Expiratory Reserve Volume (ERV)
d. Residual Volume (RV)
e. Vital Capacity (VC)
d. Inspiratory Capacity (IC)
f. Functional Residual Capacity (FRC)
g. Total Lung Capacity (TLC)
The elastic force of the chest wall is exactly balanced by the elastic force of the lungs
f. Functional Residual Capacity (FRC)
Volumes and Ventilation
a. Tidal Volume
b. Inspiratory Reserve Volume (IRV)
c. Expiratory Reserve Volume (ERV)
d. Residual Volume (RV)
e. Vital Capacity (VC)
d. Inspiratory Capacity (IC)
f. Functional Residual Capacity (FRC)
g. Total Lung Capacity (TLC)
TLC=IRV+TV+ERV+RV
g. Total Lung Capacity (TLC)
Volumes and Ventilation
a. Tidal Volume
b. Inspiratory Reserve Volume (IRV)
c. Expiratory Reserve Volume (ERV)
d. Residual Volume (RV)
e. Vital Capacity (VC)
d. Inspiratory Capacity (IC)
f. Functional Residual Capacity (FRC)
g. Total Lung Capacity (TLC)
3000 cc
b. Inspiratory Reserve Volume (IRV)
Volumes and Ventilation
a. Tidal Volume
b. Inspiratory Reserve Volume (IRV)
c. Expiratory Reserve Volume (ERV)
d. Residual Volume (RV)
e. Vital Capacity (VC)
d. Inspiratory Capacity (IC)
f. Functional Residual Capacity (FRC)
g. Total Lung Capacity (TLC)
500 cc
a. Tidal Volume
Volumes and Ventilation
a. Tidal Volume
b. Inspiratory Reserve Volume (IRV)
c. Expiratory Reserve Volume (ERV)
d. Residual Volume (RV)
e. Vital Capacity (VC)
d. Inspiratory Capacity (IC)
f. Functional Residual Capacity (FRC)
g. Total Lung Capacity (TLC)
IRV+TV
d. Inspiratory Capacity (IC)
Volumes and Ventilation
a. Tidal Volume
b. Inspiratory Reserve Volume (IRV)
c. Expiratory Reserve Volume (ERV)
d. Residual Volume (RV)
e. Vital Capacity (VC)
d. Inspiratory Capacity (IC)
f. Functional Residual Capacity (FRC)
g. Total Lung Capacity (TLC)
ERV+RV
f. Functional Residual Capacity (FRC)
Volumes and Ventilation
a. Tidal Volume
b. Inspiratory Reserve Volume (IRV)
c. Expiratory Reserve Volume (ERV)
d. Residual Volume (RV)
e. Vital Capacity (VC)
d. Inspiratory Capacity (IC)
f. Functional Residual Capacity (FRC)
g. Total Lung Capacity (TLC)
1100 cc
c. Expiratory Reserve Volume (ERV)
Volumes and Ventilation
a. Tidal Volume
b. Inspiratory Reserve Volume (IRV)
c. Expiratory Reserve Volume (ERV)
d. Residual Volume (RV)
e. Vital Capacity (VC)
d. Inspiratory Capacity (IC)
f. Functional Residual Capacity (FRC)
g. Total Lung Capacity (TLC)
Point at which the elastic forces of the lungs and chest wall equalize each other
f. Functional Residual Capacity (FRC)
WHY and HOW does air move in and out of the lungs?
General Principle: Air moves from a greater to a lower
pressure.
Usually same as atmospheric pressure
Mouth Opening Pressure
Difference between the mouth opening pressure and alveolar pressure
Airway Pressure
Difference between the alveolar and intrapleural pressure
Transpulmonary Pressure
Statement 1: Lungs and chest wall have opposite elastic properties
Statement 2: Lungs have natural tendency to expand and the chest wall has natural tendency to collapse
a. TF
b. FT
c. TT
d. FF
a. TF
Lungs: collapse
Chest wall: expand
Atmospheric Gas Composition
Nitrogen
78.62%
Atmospheric Gas Composition
H2O vapor
0.50%
Atmospheric Gas Composition
Oxygen
20.84%
Atmospheric Gas Composition
Carbon Dioxide
0.04%
Statement 1: In the anatomic dead space, oxygen added by airway mucosa dilutes other gasses
Statement 2: O2 concentration decreases in the alveoli due to diffusion from the alveoli into the pulmonary capillaries; reverse for CO2 is true
a. TF
b. FT
c. TT
d. FF
b. FT
H2O vapor added by airway mucosa dilutes other gasses
Statement 1: In the AC Membrane, the Rate of diffusion is proportional with solubility and pressure difference
Statement 2: Rate of diffusion is inversely proportional with molecular weight
a. TF
b. FT
c. TT
d. FF
c. TT
AC Membrane: Alveolar-Capillary Membrane
T/F: CO2 is heavier than O2 but 20x more soluble than O2
True
Gas Tension
Because of the gas tension gradient, oxygen diffuses from the [?] into the [?] while CO2 diffuses out from the [?] into the [?]
Oxygen: Alveoli –> Pulmonary Capillary Blood
CO2: Pulmonary Capillary Blood –> Alveoli
Transit time of blood pulmonary capillary transit (normal & during exercise)
Normal: 0.7sec
During Exercise: 0.3 sec
T/F: Blood stays in the alveoli for more than enough time for adequate gas exchange
False: Blood stays in the capillaries for more than enough time for adequate gas exchange
Statement 1: It takes 0.23 sec for CO2 to diffuse into the alveoli
Statement 2: It takes only 0.17 sec for O2 to diffuse into the alveoli
a. TF
b. FT
c. TT
d. FF
d. FF
0.23 sec for O2; 0.17 sec for CO2
Blood-Gas Barrier
- Aqueous fluid layer (surfactants)
- Alveolar epithelium
- Epithelial basement membrane
- Intersitium
- Endothelium basement membrane
- Capillary endothelium
- Plasma
- Red cell membrane
- Intracellular fluid
Relationship between respiratory unit’s ventilation (V) and perfusion or blood flow (Q)
V/Q Matching
Statement 1: Ventilation and perfusion are greatest in more dependent portions of the lungs
Statement 2: V/Q is the best at the apex and the Effect of gravity: V < Q
a. TF
b. FT
c. TT
d. FF
a. TF
Effect of gravity: V > Q
Types of VQ (MIS) MATCHING
a. Ideal, V = Q
b. Low V/Q, V < Q
c. No V but normal Q
d. High V/Q, V > Q
e. With V but not without Q
V/Q < 1
b. Low V/Q, V < Q
Types of VQ (MIS) MATCHING
a. Ideal, V = Q
b. Low V/Q, V < Q
c. No V but normal Q
d. High V/Q, V > Q
e. With V but not without Q
V/Q > 1
d. High V/Q, V > Q
Types of VQ (MIS) MATCHING
a. Ideal, V = Q
b. Low V/Q, V < Q
c. No V but normal Q
d. High V/Q, V > Q
e. With V but not without Q
V/Q = 1
a. Ideal, V = Q
Types of VQ (MIS) MATCHING
a. Ideal, V = Q
b. Low V/Q, V < Q
c. No V but normal Q
d. High V/Q, V > Q
e. With V but not without Q
V/Q = 0
c. No V but normal Q
Types of VQ (MIS) MATCHING
a. Ideal, V = Q
b. Low V/Q, V < Q
c. No V but normal Q
d. High V/Q, V > Q
e. With V but not without Q
V/Q Infinite
With V but not without Q
Determinants of O2 Content
- Minute ventilation
- Dead space ventilation
- Alveolar ventilation
- O2 association/dissociation
- Hemoglobin level
Statement 1: Bases are 6x better perfused than the apices
Statement 2: Bases are 3x better ventilated than the apices
a. TF
b. FT
c. TT
d. FF
b. FT
Bases are 8x better perfused than the apices
V/Q Mismatch Patterns
Upper Lung
High V/Q
V/Q Mismatch Patterns
Mid Lung
V/Q of I
V/Q Mismatch Patterns
Lower Lung
Low V/Q
Average V/Q of a normal upright lung
0.8
2 Patterns of Breathing
Resides within the brainstem & influenced by the RAS
Metabolic (Autonomic) Control
2 Patterns of Breathing
Concerned with coordinating breathing and can override spontaneous activity
Behavioral (Voluntary) Control
2 Patterns of Breathing
Resides within the thalamus and cerebral cortex
Behavioral (Voluntary) Control
2 Patterns of Breathing
Concerned with O2 delivery and acid-base balance
Metabolic (Autonomic) Control
Respiratory Centers (Location)
a. Dorsal Respiratory Group
b. Ventral Respiratory Group
c. Pneumotaxic
d. Apneustic
Ventral medulla
b. Ventral Respiratory Group
Respiratory Centers (Location)
a. Dorsal Respiratory Group
b. Ventral Respiratory Group
c. Pneumotaxic
d. Apneustic
Dorsal medulla
a. Dorsal Respiratory Group
Respiratory Centers (Location)
a. Dorsal Respiratory Group
b. Ventral Respiratory Group
c. Pneumotaxic
d. Apneustic
Lower pons
d. Apneustic
Respiratory Centers (Location)
a. Dorsal Respiratory Group
b. Ventral Respiratory Group
c. Pneumotaxic
d. Apneustic
Upper pons
c. Pneumotaxic
Respiratory Centers (Effect)
a. Dorsal Respiratory Group
b. Ventral Respiratory Group
c. Pneumotaxic
d. Apneustic
Tends to terminate inspiration; contains both inspiratory and expiratory neurons
c. Pneumotaxic
Respiratory Centers (Effect)
a. Dorsal Respiratory Group
b. Ventral Respiratory Group
c. Pneumotaxic
d. Apneustic
Active during inspiration; promotes inspiration; generated basic respiratory rhythm
a. Dorsal Respiratory Group
Respiratory Centers (Effect)
a. Dorsal Respiratory Group
b. Ventral Respiratory Group
c. Pneumotaxic
d. Apneustic
Some neurons are active during all phases of cycle esp. during expiration
b. Ventral Respiratory Group
Respiratory Centers (Effect)
a. Dorsal Respiratory Group
b. Ventral Respiratory Group
c. Pneumotaxic
d. Apneustic
Promotes inspiration
d. Apneustic
Respiratory Centers (Purpose)
a. Dorsal Respiratory Group
b. Ventral Respiratory Group
c. Pneumotaxic
d. Apneustic
Inhibits the DRG. Primarily most active during the expiratory phase.
b. Ventral Respiratory Group
Respiratory Centers (Purpose)
a. Dorsal Respiratory Group
b. Ventral Respiratory Group
c. Pneumotaxic
d. Apneustic
Drive the phrenic motor neurons and VRG cells when there is a need to increase respiratory rate (decrease expiratory phase)
a. Dorsal Respiratory Group
Respiratory Centers (Purpose)
a. Dorsal Respiratory Group
b. Ventral Respiratory Group
c. Pneumotaxic
d. Apneustic
Transection increases TV and duration of inspiration resulting in slow, deep respiration with prolonged inspiratory hold (apneustic breathing)
c. Pneumotaxic
Respiratory Centers (Purpose)
a. Dorsal Respiratory Group
b. Ventral Respiratory Group
c. Pneumotaxic
d. Apneustic
Most important, rhythm generator for respiration (Mostly inspiratory neurons)
a. Dorsal Respiratory Group
Respiratory Centers (Purpose)
a. Dorsal Respiratory Group
b. Ventral Respiratory Group
c. Pneumotaxic
d. Apneustic
Inhibits the DRG. Shortens the inspiratory phase
c. Pneumotaxic
Modulate the function of the respiratory controller
Cerebral Cortex
Inhibits the DRG. Shortens the inspiratory phase
Vagus Nerve
Statement 1: Vagus Nerve carries primarily inhibitory impulses from the
mechanoreceptors or proprioceptors and chemical receptors
Statement 2: Double vagotomy results in a more profound apneustic breathing
a. TF
b. FT
c. TT
d. FF
c. TT