Respiratory Physiology: Ventilation & Resp Physiology II- pulmonary circulation (Exam 4) Flashcards
What are the 5 functions of the respiratory system?
- Exchange of gases between atmosphere and blood
- Regulation of pH
- Protection of inhaled pathogens and irritants
- Vocalization
- Route for water and heat loss
Exchange of gases between atmosphere and blood:
external respiration
Moves air in and out of lungs:
ventilation
Gases diffuse between:
alveoli and blood
What systems work together to regulate blood pH?
renal and respiratory system
Pleural membrane that attaches to the surface of the lung:
visceral pleura
Pleural membrane that covers the surface of the chest wall, diaphragm, and 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:
intrapleural pressure (Pip)
It is critical that intrapleural pressure remains at a:
subatmospheric pressure
Intrapleural pressure remains at a subatmospheric pressure which ensures:
the lungs are held to the chest wall and will move with the chest wall during inspiration and expiration
What happens to the value of intrapleural pressure during inspiration and expiration?
value changes
excess fluid in the pleural space:
pleural effusion
Effects of a pleural effusion:
makes lung expansion difficult so the person will breath shallow and fast
The extra fluid of a pleural effusion can be:
blood or lymph or etc
Each lung is located:
in its own pleural cavity
Describe the pressure in the lung tissue compared to the pleural space:
pressure is always greater in the lung tissue
The greater pressure of the lung tissue compared to the pleural space allows for:
holds the lung open, prevents collapse
During contraction what happens to the 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 and fast
the right lung has ___ lobes; the left lung has ____ lobes
right =3
left =2
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
The perfect scenario for a lung is a VQ ratio=
1
A VQ ratio of 1 would mean:
ventilation equal to perfusion
The lung is divided into ____ zones
3
All lung zones differ in the amount of:
airflow and bloodflow
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; superiorly
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 zones 2 and 3
True: in a healthy individual zone 1 is likely 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 respiratory zone we are doing this based on:
functional distinction
The trachea, bronchi, bronchioles, and terminal bronchioles are all part of the:
conducting zone
The respiratory bronchioles, alveolar ducts, and alveolar sacs are all part of the:
respiratory zone
Where does the conducting zone end? Where does the 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 the 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 within the respiratory system=
keeps airway from collapsing
What smooth muscle in the terminal bronchioles and respiratory bronchioles allow for?
bronchoconstriction and bronchodilation
Bronchoconstriction and 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 3 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 airflow
Smooth muscles 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
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 zone:
The 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 and of the alveolar epithelium:
fused
Describe where the fusion of the basement membrane occurs in the respiratory zone:
between capillary endothelium and alveolar epithelium
What is the purpose of the fusion between the basement membrane of the endothelium and of the alveolar epithelium:
faster diffusion
The respiratory membrane is made of:
2 squamous epithelial cells back to back
Types of cells in the alveoli: (3)
- Type 1 cells
- Type 2 alveolar cells
- macorphages
The type 1 cells in the alveoli are:
simple squamous epithelial cells
The type 1 cells in the aveoli make up:
the wall of the alveoli
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 the alveoli:
produce surfactant
What type of function is provided by the macrophages in the alveoli:
immune fxn- 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 capillary?
0.75 seconds
Gas exchange is usually complete in:
0.25 seconds
Diffusion equilibrium occurs when PAO2 and PaO2= ______ and when PACO2 and PaCO2 = _____
PAO2 & PaO2= 100
PACO2 & PaCO2= 40
Since the partial pressure of oxygen in the alveoli is higher than it is in the blood ( 100 vs 40) what will occur?
Oxygen will move down its gradient from the alveoli and 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 muscles
In respiratory muscles, neurons in the medulla and pons control their:
alpha motor neurons
List the key inspiratory muscles:
- diaphragm
- external intercostals
Contraction of the inspiratory muscles ____ the size of the thorax and lungs resulting in:
increases; decrease in alveolar pressure
When are expiratory muscles used?
forced expiration ONLY
List the key expiratory muscles:
internal intercostals, and abdominal muscles
Contraction of the expiratory muscles ____ the size of the thorax and lungs resulting in:
decreases; increase in alveolar pressure
If lungs appear shrunken on an x-ray, what is occuring?
expiration
If the lungs appear inflated on an x-ray, what is occuring?
inspiration
If the chest wall and lungs are expanded what process is occuring?
inspiration
During inspiration the expansion os the ribs has what effect on the sternum?
moves sternum upward and outward
If the chest cavity and lungs are contracted, what process is occuring?
expiration
During expiration what happens to the ribs and sternum?
ribs and sternum depress
The sternocleidomastoid and scalenes are muscles involved in:
inspiration
The external oblique, internal oblique, transversus abdominus and rectus abdominis are muscles involved in:
Active expiration
Active expiration occurs if you want to breathe out more than:
500ml of air
Does active expiration occur if you are calmly breathing in class?
NO
The ____ is 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 the thorax/lungs
liver; down; increases; reduces
During active expiration, the _____ Muscle push abdominal contents against the diaphragm (compressing the lungs) and the ____ depress the ribs
abdominal muscles; internal intercostals
Pressure-Volume Relationships:
- Air is a mixture of:
- Gases have different:
- Air moves from ___ to ___.
- gases
- pressures
- high pressure to low pressure
According to Boyle’s Law, in a sealed container, pressure times volume equals:
a constant
According to Boyle’s Law, if pressure increases, volume will:
decrease
According to Boyle’s 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, this is describing aspect of respiration?
inspiration
For air to LEAVE the lungs, the pressure in the alveoli (Palv) must be ____ than the atmospheric pressure?
higher
A decrease in volume and and increase in pressure is describing what aspect of respiration?
Expiration
Humans are ____ pressure breather; what does this mean?
negative, for us to breathe in we have to suck air into the lungs DOWN a pressure gradient
A preemie 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 the respiratory muscles during inspiration?
To get a volume change which will allow for the pressure to change in the opposite direction
What allows for the gradient for airflow?
Increase in alveolar pressure
The lungs and chest wall are:
Elastic
The chest wall and lungs both wish to:
recoil apart
What is the natural direction of recoil for the chest wall?
outward
What is the natural direction of record for the lung?
inward
When the chest wall recoils outward this moves it:
away from the lungs
The inward recoil of the lungs is due to:
alveoli
The elastic recoil of the lungs favors:
a decrease in lung volume or compression
The elastic recoil of he lungs favors a decrease in lung volume or compression which is ultimately favoring:
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 ultimately is favoring:
inspiration
The ____ overcomes the recoil between 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
Recoilability=
Stretchability=
elasticity
compliancy
Why do we consider the intrapleural pressure to be -5 when in reality it is 755mmHg?
Because we set atmospheric pressure which is 760mmHg equal to 0 and the intrapleural pressure is 5 less than that
A calculated value describing the pressure across the lung wall:
Transpulmonary pressure/ transmural pressure
How can transpulmonary pressure be calculated?
PTP= PALV - PIP
(Pressure of alveolus - intrapleural pressure)
An increase in transpulmonary pressure (PTP) is needed for:
Inspiration
A decrease in transpulmonary pressure (PTP) is needed for:
expiration
The bigger the value of PTP, the bigger the ____ is.
volume change
What value must always be positive in order to hold the lung open?
transpulomary pressure (PTP)
It PIP=PATM, then PTP = ____.
Describe this situation
PTP= 0
There is no longer a force to keep the lungs open (pneumothorax)
The lungs want to naturally recoil inward and ____ is what prevents this
Transpulmonary pressure (PTP)
Why does one collapse lung not cause the other lung to collapse?
Due to each lung being in their own cavity
When beginning inspiration, describe the relationship between Patm and Palv:
Patm= Palv
During inspiration, the inspiratory muscles ____ and causing the volume of the thorax (and lungs) to ____.
contract; increase
During inspiration, the increase in volume of the lungs causes what to happen to the PIP?
decrease in PIP
What is the starting value at rest for PIP? What happens with the initial change in volume?
-5; it goes to -7.5
During inspiration, the increase in volume of the lungs that causes a decrease in PIP, causes what to happen to PTP? Explain why:
Increase in PTP; because PTP= Palv- Pip
where we are getting these values:
Palv = 0 at rest
PIP started at -5. and with the initial change in volume decreased to -7.5 which is why we get an increase in PTP (because we are subtracting a larger negative number)
During inspiration, after PTP has increase, this causes what to happen with Palv?
Palv decreases to -1mmg (from 0 where it started at rest)
When Palv<Patm, air:
flows into the lungs
When Palv<Patm, air flows into the lungs:
a: as air enters the lungs, Palv:
b: Air flow continues until:
a: Palv begins to increase again
b: Palv = Patm
During inspiration, when Palv is less than Patm air flows down its concentration gradient into the lungs. What eventually will happen as air flows in?
Palv= Patm so no more air will flow into the lungs because no difference in pressure = no difference in flow
During resting breathing, what amount of air is moved into the lungs? What is this considered?
500ml; tidal volume
Why is expiration considered a passive process?
because we just have to rely out inspiratory muscles
Expiration begins after inspiration when:
Patm= Palv
Relaxed breathing is referred to as:
eupnea
In expiration, the thorax (and thus the lungs) ____ in volume
decrease
In expiration, the lung volume decrease because the decrease in thorax volume causes a ____ in PIP
increase
In expiration, an increase in PIP causes PTP to:
decrease
In expiration, an increase in PIP causes PTP to:
decrease
In expiration, because volume decrease, lung pressure (Palv):
increases (to +1mmHg)
During expiration, as soon as Palv> Patm, air flows:
down pressure gradient and out of the lungs
What happens to Palv as air is leaving the lungs:
Palv decreases
During expiration, when Palv=Patm:
airflow stops
Compliance =
Change in volume / change in pressure
if the lung stretches easily it has a ____ compliance
high
If the lung is difficult to stretch it has a ___ compliance
low
describe the compliance of the alveoli in the base o the lung; what does this allow for?
the alveoli in the base of the lungs are more compliant and undergo greater expansion during inspiration
The opposite of compliance is elasticity which describes the lungs ability:
to return to its normal, resting position
Easy stretch describes:
Easy recoil describes:
high compliance
high elasticity
Lungs with a lower compliance require _____ to _____.
larger transpulmonary pressure to increase volume
Disease characterized by the destruction of elastic fibers resulting in an increased compliance
Obstructive lung disease
An example of an obstructive lung disease:
emphysema
describe the pattern of breathing for an individual effected by an obstructive lung disease:
deep slow breaths
Why might someone with obstructive lung disease take slow deep breaths?
to reduce the work of breathing
A disease characterized by decreased compliance of the lungs:
restrictive lung disease
What is an example of a restrictive lung disease?
pulmonary fibrosis
describe the breathing pattern of an individual effected by a restrictive lung disease:
shallow and fast breaths
Why might someone with a restrictive lung disease take shallow, fast breaths?
to reduce the work of breathing
accounts for 2/3s of pulmonary elasticity:
surface tension
forces that occur at any gas-liquid interface due to cohesive forces between liquid molecules
surface tension
Surface tension describes the force that occurs at any ____ interface due to the ___ forces between ___ molecules
gas-liquid; cohesive; liquid
The fluid covering of alveoli exerts a constant force favoring:
contraction
The fluid covering of alveoli exerts a constant force favoring attraction which means:
collapse of alveoli
Describes the relationship between surface tension and radius if an alveolus:
The Law of LaPlace
Label the following image:
A: IRV
B: TV
C: ERV
D: RV
What situation is this showing?
perfusion of well ventilated alveoli and maximal gas exchange
What situation is this showing?
Perfusion of a hypoventilated alveolus with no response of vasoconstriction = decrease PaO2
What situation is this showing?
hypoxic pulmonary vasoconstriction (HPV) in response to a decreased PAO2 (which works to reduce blood flow to hypoventilated alveoli)
