CH 37: Pulmonary Ventilation Flashcards
Four Functions of Respiratory System–1
1) ________ __________—the inflow and outflow of air between the atmosphere and the lungs.
Pulmonary Ventilation
Four Functions of Respiratory System–2
2) ________ __________—the exchange of O2 and CO2 between the alveoli and the pulmonary capillaries.
Pulmonary Diffusion
Four Functions of Respiratory System–3
3) _____ _______—transport of gases to and from the body’s tissues.
Gas Transport
Four Functions of Respiratory System–4
4) _________ ___________—muscle and pressure contributions to respiration.
Regulation of Ventilation
Anatomy-1
The lungs are comprised of lobes.
• Because the _______ lung has three lobes, the superior lobe, middle lobe and inferior lobe, this lung is slightly larger.
right
Anatomy–2
The _______ lung has two lobes, the superior lobe and the inferior lobe.
left
Respiratory Passageways–1
- Air is taken in through the nose and mouth
- Travels through pharynx and larynx before it enters the ______.
trachea
Respiratory Passageways—2
- Trachea branches into major bronchi and eventually to bronchioles.
- At the end of the bronchioles are the alveolar sacs.
- It is in the alveolar sacs that __________ diffusion occurs— CO2 leaves the capillaries and O2 is taken up and transported via the blood to the body’s tissues.
pulmonary
Passageway Linings–1
- An important challenge of the respiratory passageways is to keep them open to allow air to travel to and from the alveoli.
- The trachea is kept open by multiple _____ _______ that help provide a rigid structure to remain open.
- The walls of the _________ also have cartilage rings but they are less rigid so the lungs are able to expand and contract.
cartilage rings
bronchi
Passageway Linings–2
- In the areas of the trachea and bronchi where cartilage is not present, the walls are composed of ______ ______.
- The bronchioles and alveoli do NOT contain cartilage so are kept open by the ____________ pressures.
smooth muscle
transpulmonary
Passageway Linings–3
- The bronchioles are almost all smooth muscle except for the terminal bronchioles (called ________ _________). These terminal bronchioles are made almost entirely of pulmonary __________ and underlying fibrous tissue.
- Obstructive lung diseases are often a result of excessive __________ of the smooth muscle itself.
respiratory bronchioles
epithelium
contraction
Airflow
• The greatest amount of resistance to airflow actually occurs in the bronchi and some of the larger bronchioles because there are NOT nearly as many larger bronchioles as there are __________ bronchioles. Therefore, there is only a minute amount of air going through each terminal bronchiole.
• However, in disease conditions, it is these smaller terminal bronchioles that are often _________ by (a) mucus and/or
(b) pulmonary edema.
terminal
occluded
Nervous and Local Control of Bronchiolar Musculature–1
_____________ (Constriction)—nerve fibers from the _________ nerves release Ach which will cause mild to moderate constriction of the bronchioles .
Parasympathetic
vagus
Nervous and Local Control of Bronchiolar Musculature–2
Sometimes the parasympathetic nerves are activated by reflexes within the lungs themselves. This _________ _________ reflex is usually in response to irritation to the epithelial membrane by cigarette smoke, dust, noxious gases, bronchial infections, or microemboli occluding the small pulmonary ________.
bronchiolar constrictor
arteries
Nervous and Local Control of Bronchiolar Musculature–3
Two of the most active substances for causing more intense bronchiolar constriction are _________ and slow reactive substance of ___________. These are released in lung tissue by mast cells during allergic reactions and cause airway obstruction.
histamines
anaphylaxsis
Nervous and Local Control of Bronchiolar Musculature–4
___________ (dilation)—there are few direct sympathetic fibers that innervate the central portions of the lungs. However, epinepherine and norepinepherine are carried in the blood and can cause _________ in the bronchioles.
__________ contributes the most as it binds to ____-___________ receptors and causes dilation of the bronchiolar tree.
Sympathetic
dilation
Epinepherine
beta-adrenergic
Mucus Lining and Cilia Action to Clear Passageway–1
1–The respiratory passageways from the nose to the terminal bronchioles are kept moist with a layer of mucus.
2–The mucus is secreted by (a) individual mucous ________ cells in the epithelial lining and (b) small _____-_________.
3–The mucus keeps the passageways moist and mucus helps trap small particles from the inspired air and keeps them from reaching the alveoli.
goblet
submucosal glands
Mucus Lining and Cilia Action to Clear Passageway–2
4–The respiratory passageways are also lined with small, hair-like structures called ______. ________ (cilia). These cilia continually beat at a rate of ___ to _____ times per second.
ciliated epithelium
10–20
Mucus Lining and Cilia Action to Clear Passageway–3
5–The “_______ ________” of the cilia is always in the direction of the pharynx. Therefore, cilia in the passageways inside the lungs beat ________ and the cilia in the nose beats ________.
6– The continual beating of the cilia moves the mucus slowly toward the ________ where the mucus and entrapped particles are either swallowed or coughed to the exterior.
power stroke
upward
downward
pharynx
Muscle Contribution to Respiration–1
In order for ventilation to occur, the _______ cavity must be able to expand and contract so that the lungs can perform those same movements.
This expansion and contraction of the thoracic cavity allows for inspiration and expiration.
thoracic
Muscle Contribution to Respiration–2
- INSPIRATION
- Process—the thoracic cavity increases to allow the lungs to expand. When the lungs expand, the pressure inside the lungs ________ allowing air to come into the lungs.
- Muscles Involved—under RESTING conditions, the diaphragm contracts and moves _________ as the external intercostals contract and move the ribs outward and _________.
decreases
downward
upward
Muscle Contribution to Respiration–3
- EXPIRATION
- Process—under resting conditions, expiration is a ______ ______. The ribs return to normal position through the elastic recoil of the lungs and chest wall therefore, the lungs become smaller and the pressure inside the lungs _________ thereby forcing air out of the lungs.
- Muscles Involved—the ________ and the _________ intercostals simply relax.
passive process.
increases
diaphragm
external
Functions of the Nose–1
As air passes through the nose, it performs three functions which benefits nose breathing over mouth breathing:
- Air is ______—as it passes over the surface area of the conchae and septum. The air is within 1 degree F of body temperature before it reaches the trachea.
- Air is ________—it becomes within 2 to 3% of full saturation with water vapor before it arrives at the trachea.
warmed
humidified
Functions of the Nose–2
- Air is _______—the hairs in the entrance of the nose filter large particles but the _________ of air hitting the conchae and septum also help with trapping particles. The air itself can change directions but the particles, because of their mass relative to air, do NOT change directions and become entrapped in the mucus lining.
filtered
turbulence
Ventilation During Normal, “Quiet” Breathing-1
REMEMBER!!!
Inspiration
• The diaphragm contracts and moves DOWNWARD (flattens) and the ribs
move UPWARD and OUTWARD!!
Ventilation During Normal, “Quiet”Breathing-2
REMEMBER!!
Expiration
The diaphragm relaxes and the ELASTIC RECOIL of the lungs, chest wall, and abdominals compresses the lungs and the ribs return to normal position.
Expiratory Muscles When Respiration Rate Increases (exercise, frightened, stress, etc.)-1
1–Under these conditions, the muscles that pull the rib cage downward and inward during EXPIRATION include the (1) _____ _____and (2) the _________ intercostals.
rectus abdominus
internal
Expiratory Muscles When Respiration Rate Increases (exercise, frightened, stress, etc.)-2
The energy required for respiration (pulmonary ventilation) at rest is 3 to 5% of the total energy expenditure. During heavy exercise that percentage of energy expenditure can increase _____-fold.
50
____ _______—also known as the pleural sac is a body cavity that surrounds the lungs. The actual space of the pleural cavity is filled with a thin layer of pleural fluid between the visceral pleura of the lungs and the parietal pleura of the thoracic cavity, which are almost in contact. The ________ _______provides lubrication so the lungs can slide freely as the chest expands and contracts
Pleural cavity
pleural fluid
Each lung is an elastic structure that collapses like a balloon whenever there is no force (pressure) to keep it inflated.—1
- _________ Pressure—is the pressure within the pleural cavity and is measured as a _________ pressure. As noted on the diagram, at the beginning of inspiration, pleural pressure measures -5 and by the end of inspiration, the pressure falls to -7.5.
Pleural
negative
Each lung is an elastic structure that collapses like a balloon whenever there is no force (pressure) to keep it inflated.—2
- _________ Pressure—is the pressure inside the alveoli and at the beginning of inspiration the alveolar pressure is __. During normal, resting inspiration, this pressure falls to a ____ cm H2O which is low enough to pull 0.5 L of air into the lungs in the 2 sec. of normal inspiration. During expiration, alveolar pressure increases to ___ to force 0.5 L of air out in 2 to 3 sec. of expiration.
Alveolar
0
-1
+1
Each lung is an elastic structure that collapses like a balloon whenever there is no force (pressure) to keep it inflated.—3
- __________ Pressure—is the difference between alveolar pressure and pleural pressure. This pressure measures the elastic forces in the lungs—called the _____ ______.
Transpulmonary
recoil pressure
Spirometry
- Like an ECG or an EMG, the spirogram is a recording of a person’s ventilation of air in and out of the lungs.
- The spirometer shown in the diagram consists of a drum inverted over a chamber of water and the drum is counterbalanced by a weight.
- As the individual breathes in and out through the mouth piece, the drum rises and falls with a pen recording the movements on the paper (see red arrow)
SEE SLIDE 18
- As the drum moves, the pen records the movement of air under the various conditions of breathing.
- Ventilatory measurements on the spirogram are subdivided into lung VOLUMES and lung CAPACITIES
Pulmonary Volumes–1
- _________ ________—the volume of air inspired and expired in a normal (resting) breath. VT is usually 500 mls for an adult.
Tidal Volume (VT)
Pulmonary Volumes–2
- __________ __________ _______—the maximum volume of air that can be forcefully inspired above VT.
Inspiratory Reserve Volume (IRV)
Pulmonary Volumes—3
- ________ ______ _______—the maximum volume of air that can be forcefully expired at the end of VT expiration.
Expiratory Reserve Volume (ERV)
Pulmonary Volumes—-4
- _________ ___________—the volume of air remaining in the lungs after the most forceful expiration.
Residual Volume (RV)
Pulmonary Capacities–Pulmonary capacities are derived from two or more pulmonary volume measurements.–1
- ________ _________—startingattheendof a normal expiration and forcefully taking in as much air as possible. VT + IRV
Inspiratory Capacity (IC)
Pulmonary Capacities–Pulmonary capacities are derived from two or more pulmonary volume measurements.–2
- ______ _________ ______—the amount of air remaining in the lungs after a normal expiration. ERV + RV
Functional Residual Capacity (FRC)
Pulmonary Capacities–Pulmonary capacities are derived from two or more pulmonary volume measurements.–3
- ______ _________—thisisthemaximum amount of air a person can forcefully expire after taking in a maximal inspiration. IRV + VT + ERV
Vital Capacity (VC)
Pulmonary Capacities–Pulmonary capacities are derived from two or more pulmonary volume measurements.–4
- _________ ________ ________—representsthe greatest volume the lungs can expand with the greatest possible effort. VC + RV
Total Lung Capacity (TLC)
Helium Dilution Method of Calculating RV
______ _________ __________ is the volume of air remaining in the lungs after a normal expiration (ERV + RV). However, RV cannot be directly measured using normal spirometric methods.
Functional Residual Capacity (FRC)
Helium Dilution Method of Calculating RV
A helium dilution method is used to calculate RV and thus FRC. The spirometer is filled with a known concentration of _______and________. The person breathes the mixture and soon the lungs fill and the mixture will soon be diluted by the air in the RV. Based on the degree of dilution of the helium over a certain period of time, RV can be calculated.
• RV and FRC measurements are important when diagnosing pulmonary diseases.
air and helium
__________ __________ ________—this is the amount of
new air entering the respiratory passageways each
minute; this equals tidal volume (VT) times respiration
rate (RR/min).
Minute Respiratory Volume (VE)
