Respiratory Physiology: Ventilation (Exam IV) Flashcards
What are the five functions of the respiratory system?
- Exchange of gases between atmosphere & blood
- Regulation of pH
- Protection of inhaled pathogens & irritants
- Vocalization
- Route for water & heat loss
Exchange of gases between atmosphere and the blood
External respiration
Moves air in and out of lungs
Ventilation
Gases diffuse between:
Alveoli & blood
What systems work collaboratively to regulate blood pH?
Renal & respiratory systems
Pleural membrane that attaches to the surface of the lung:
Visceral pleura
Pleural membrane that covers the surface of the chest wall, diaphragm, & mediastinum:
Parietal pleura
Pleural membrane that contains a thin layer of pleural fluid (serous fluid) under negative pressure:
Pleural space
The pressure in the pleural space is referred to as:
Intralpleural pressure (Pip)
It is critical that intrapleural pressure (Pip) remains:
At a subatmospheric pressure
Intrapleural pressure remains at a subatmospheric pressure to ensure that:
The lungs are held to the chest wall and will move with the chest wall during inspiration & expiration
What happens to the value of intrapleural pressure during inspiration & expiration?
It changes
Excess fluid in the pleural space
Pleural effusion
Effects of a pleural effusion:
Makes lung expansion difficult so the person will breath shallow & fast
The extra fluid in a pleural effusion can be:
Blood, lymph or etc.
Each lung is located in:
Its own pleural cavity
Describe the pressure in the lung tissue compared to the pleural space:
Always greater
The greater pressure of the lung tissue compared to the pleural space allows for:
Holds lung open & prevents collapse
During contraction what happens to the diaphragm, what does this cause?
Diaphragm flattens which changes volume of thoracic cavity
Lung expansion is necessary for:
Inhalation
Describe the breathing pattern of an individual with a pleural effusion:
Breathing= shallow & fast
The right lung has ___ lobes while the left lung has ___ lobes
Three
Two
Each lung has zones that differ in:
- amount of air (ventilation)
- amount of blood received (perfusion)
Ventilation is represented by:
Perfusion is represented by:
V
Q
A perfect scenario for the lung is a VQ ratio of:
One
A VQ ratio of one would mean:
Ventilation is equal to perfusion
The lung is divided into ____ zones
Three
All lung zones differ in the amount of:
Airflow & blood flow
The most narrow portion of an organ:
The broadest surface of an organ:
Apex
Base
The base of the lung is located _______ while the apex is located _____
Inferiorly; superior
Zone 1 is located at the _____
Zone 3 is located at the ____
Apex; base
There is a greater ventilation (V) of alveoli and blood flow (Q) into capillaries in zone ____ compared to other zones:
Zone 3
Which zone is the best region for gas exchange?
Zone 3
T/F: Normally, most of the lungs are in zone 2 & 3
True
In a healthy individual zone 1 is likely insignificant/nonexistant
The respiratory system is divided into what two functional zones:
Conducting zone
Respiratory zone
When we divide the respiratory system into the conducting zone and the respiratory zone we are doing this based on:
Functional distinction
The trachea, bronchi, bronchioles & terminal bronchioles are all part of the:
Conducting zone
The respiratory bronchioles, alveolar ducts & alveolar sacs are al part of the:
Respiratory zone
Where does the conducting zone end?
Where respiratory zone begin?
Terminal bronchioles
Respiratory bronchioles
As you move down the respiratory system from the conducting zone to the respiratory zone, the diameter of tubes ______ and the number of tubes ____
Decreases
Increases
There is a large ______ as you move deeper into the conducting zone and exchange surfaces
Increase in surface area
What is significance of the increase in surface area as you move deeper into the conducting zone and exchange surfaces:
Increased ability to do gas exchange
As you move down the respiratory system from the conducting zone to the respiratory zone, airways have a ____ in cartilage and a ______ in smooth muscle as you move along the airways
Decrease
Increase
Benefit of cartilage in the respiratory system:
Keeps airway from collapsing
What does the smooth muscle in the terminal bronchioles & respiratory bronchioles allow for?
Bronchoconstriction & Bronchodilation
Bronchoconstriction & bronchodilation allow us to match:
Ventilation to areas of good blood flow
T/F: The conducting zone has cartilage. The conducting zone has smooth muscle
Both statements true
What three functions occur in the conducting zone?
- Air is warmed
- Air is humidified
- Air is filtered
In the conducting zone, describe the functions of cartilage and smooth muscle:
Cartilage prevents collapse; smooth muscle alters resistance to air flow
Smooth muscle alters ____ to airflow in the conducting zone
Resistance
What are some factors that allow smooth muscle to alter the resistance to airflow in the conducting zone?
Beta-2 receptors
Muscarinic receptors
Allergen activation (asthma)
The ____ zone has a greater surface area to optimize the surface area available for gas exchange
Respiratory zone
Equation for velocity:
Velocity= Flow / Cross-sectional area
Total cross-sectional area greatly increases in the respiratory zone. so velocity of airflow in this zone is:
low
What is the significance of the low velocity of airflow in the respiratory zone?
The slower air moves (velocity) the more time we have for gas exchange
Describe the total cross-sectional area of the conducting zone compared to the respiratory & why?
Total cross sectional area of the respiratory zone is much greater due to numerous bronchioles compared to ONE trachea
Describe the basement membrane of the endothelium & of the alveolar epithelium
Fused
Describe where the fusion of the basement membrane occurs in the respiratory zone:
Between the simple squamous endothelium of the capillary & alveolar epithelium
What is the purpose of the fusion between the basement membrane of the endothelium and alveolar epithelium?
Allows for faster diffusion process
The respiratory membrane is made of:
Two squamous epithelial cells back to back
Types of cells in alveoli include: (3)
- Type 1 cells
- Type 2 alveolar cells
- Macrophages
The type-1 cells in the alveoli are:
Simple squamous epithelial cells
The type-1 cells in the alveoli make up:
The wall of the alveoli
Describe what occurs through the type-1 cells, making up the wall of the alveoli:
Gas exchange
Describe the function of the type-2 alveolar cells in alveoli:
Produce surfactant
What type of function is provided by the macrophages in the alveoli?
Immune function, specifically phagocytosis
The typical transit time at rest for an erythrocyte through an alveolar capillary is:
0.75 seconds
How much time is available for gas exchange to occur for a RBC through the alveolar capillaries?
0.75 seconds
Gas exchange is usually complete in:
0.25 seconds
Diffusion equilibrium occurs when PAO2 and PaO2= _____ & when PACO2 and PaCO2= ____
PAO2 & PaO2= 100
PACO2 & PaCO2= 40
Since the partial pressure of oxygen in the alveoli is higher than in the blood, (100 vs. 40) what will occur?
Oxygen will move down its gradient from the alveoli into the blood
Since the partial pressure of CO2 is higher in the blood than in the alveoli (45 vs. 40) what will occur?
CO2 will move down its concentration gradient from the blood into the alveoli
When talking about partial pressures:
A=
a=
A= Alveolar
a= blood
Moving air in and out of the lungs:
Ventilation
Respiratory muscles are ____ muscles
Skeletal
In respiratory muscles, neurons in the medulla and pons control their:
Alpha motor neurons
List the key inspiratory muscles:
- Diaphragm
- External intercostals
The contraction of inspiratory muscles _____ the size of the thorax and lungs resulting in a:
Increases; Decrease in alveolar pressure
When are expiratory muscles used?
Forced expiration ONLY
List the key expiratory muscles:
Internal intercostals
Abdominal muscles
Contraction of the expiratory muscles ____ the size of the thorax & lungs resulting in:
Decreases; Increase in alveolar pressure
If the lungs appear shrunken on an X-ray what is occurring?
Expiration
If the lungs appear inflated on an X-ray what is occurring?
Inspiration
If the chest wall and lungs are expanded what process is occurring?
Inspiration
During inspiration, the expansion of the ribs has what affect on the sternum?
Moves sternum upward & outward
If the chest cavity and lungs are contracted, what process is occurring?
Expiration
During expiration what happens to the ribs and sternum?
Ribs and sternum depress
The sternocleidomastoid & scalene are muscles involved in:
Inspiration
The external oblique, internal oblique, transversus abdominus & rectus abdomens are muscles involved in:
Active expiration
Active expiration occurs if you want to breath out more than:
500 mL of air
Doe does active expiration occur when you are calmly breathing during class?
NO
The primary inspiratory muscle:
Diaphragm
The diaphragm arches over the _____ and moves ____ like a piston when it contracts, which ___ the size of the thoracic cavity and _____ the pressure in thorax/lungs
liver; down; increases; reduces
During active expiration. the ____ muscles push abdominal contents against the diaphragm (compressing the lungs) and the ____ depress the ribs
Abdominal muscles; internal intercostals
Pressure-Volume Relationship:
- Air is a mixture of ______
- Gases have different ______
- Air moves from _____ to _____
- Gases
- Pressures
- High pressure to low pressure
According to Boyles Law, in a sealed container, pressure times volume equals a _______
Constant
According to Boyles Law, if pressure increases, volume will ______
Decrease
According to Boyles Law, what variable will change first? What variable will change first with respiration?
Pressure; Volume
How does the respiratory system get a change in volume?
Contraction of muscles
For air to ENTER the lungs, the pressure in the alveoli (Palv) must be _______ than atmospheric pressure (Patm)
Lower
If volume is increasing and pressure is decreasing what aspect of respiration is being described?
Inspiration
For are to LEAVE the lungs, the pressure in the alveoli (Palv) must be _____ than the atmospheric pressure (Patm)
higher
A decrease in volume, and an increase is pressure is describing what aspect of respiration?
Expiration
Humans are ______ pressure breathers, what does this mean?
Negative; We have to suck air into the lungs DOWN a pressure gradient
A premature baby is put on positive pressure ventilation, what does this mean?
Air is being pushed into the lungs rather than pulled into it
What is the purpose of contracting respiratory muscles during inspiration?
To get a volume change, which will then allow for the pressure to change in the opposite direction
What allows for the gradient for airflow?
Increase in alveolar pressure
Lungs and chest walls are:
Elastic
The chest walls and lungs both wish to:
Recoil apart
What is the desired direction of recoil for the chest wall?
Outward
What is the desired direction of recoil for the lungs?
Inward
When the chest wall recoil outward, this moves it:
Away from the lungs
The inward recoil of the lungs is due to:
Alveoli
The elastic recoil of the lung favors:
a decrease in lung volume or compression
The elastic recoil of the lungs favors a decrease in lung volume or compression, which is ultimately favoring what aspect of respiration?
Expiration
The elastic recoil of the chest wall favors:
An increase in lung volume or expansion
The elastic recoil of the chest wall favors an increase in lung volume or expansion, which is ultimately favoring what aspect of respiration?
Inspiration
The ______ overcomes the recoil of the lungs and chest wall
Intrapleural fluid
The intrapleural fluid overcomes the recoil of the lungs and chest wall keeping the two:
Attached together, so when the chest moves the lungs move with it
Label the following image:
a) IRV
b) TV
c) ERV
d) RV
