Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
201 Cards in this Set
- Front
- Back
- 3rd side (hint)
1. The primary purpose of the respiratory system is
|
Gas exchange
|
|
|
Gas exchange involves the transfer of
|
i. oxygen (O2) and carbon dioxide (CO2)
between ii. the atmosphere and the blood |
|
|
The respiratory system is divided into HOW MANY PARTS?
|
a. the upper respiratory tract
b. The lower respiratory tract |
|
|
1. The upper respiratory tract includes WHAT
|
a. nose
b. mouth c. pharynx d. epiglottis e. larynx f. trachea |
|
|
WHY do aveoli have anatural tendency to collapse
|
Because alveoli are unstable
|
|
|
3. Alveolar cells secrete what
|
surfactant
|
|
|
what is sarfactant |
4. Surfactant is a lipoprotein that lowers the surface tension in the alveoli
|
|
|
what does Surfactant do |
It reduces the amount of pressure needed toinflate the alveoli and makes them less likely to collapse
|
|
|
what is the name of the slightly larger breath that each person takes after every five or six breaths |
Sigh |
|
|
that does the sign do |
This sighstretches the alveoli and promotes surfactant secretion
|
|
|
What happens When not enough surfactant is present,
|
the alveoli collapse
|
|
|
8. The term atelectasis refers towhat?
|
collapsed, airless alveoli
|
|
|
The postoperative patient is at risk for atelectasis because of what?
|
the effects of anesthesia and restricted breathing with pain
|
|
|
In acute respiratory distress syndrome (ARDS), lack of surfactant contributes to what?
|
widespread atelectasis
|
|
|
1. what are the lungs two different types of circulation
|
a. pulmonary
b. bronchial |
|
|
2. The pulmonary circulation provides what?
|
the lungs with blood that participates in gas exchange
|
|
|
3. The pulmonary artery receives what?
and delivers it where? |
deoxygenated blood from the right ventricle of the heart
and delivers it to pulmonary capillaries that are directly connected with alveoli |
|
|
The pulmonary veins do what?
|
return oxygenated blood to the left atrium
|
|
|
The left atrium delivers blood where? |
to the left ventricle
|
|
|
where do the left ventricle pump blood to? |
into the aorta |
|
|
what does the aorta do with the blood |
supplies the arteries of the systemic circulation
|
|
|
Venous blood is collected from
|
capillary networks of the body returned to the right atrium by way of thevenae cavae
|
|
|
The bronchial circulation starts with |
the bronchial arteries
|
|
|
bronchial arteries arise from the |
thoracic aorta
|
|
|
Deoxygenated blood returns from the bronchial circulation through the |
azygos vein into the superior vena cava
|
|
|
The bronchial circulation provides
|
oxygen to the bronchi and other pulmonary tissues
|
|
|
The chest wall is shaped, supported, and protected by
|
24 ribs (12 on each side)
|
|
|
The ribs and the sternum do what? |
protect the lungs and the heart from injury
|
|
|
The ribs and the sternum are called |
the thoracic cage
|
|
|
The chest cavity is lined with |
a membrane called the parietal pleura,
|
|
|
and the lungs are lined with |
a membrane called the visceral pleura
|
|
|
The parietal and visceral pleurae join to form |
a closed, double-walled sac
|
|
|
The visceral pleura does not have |
any sensory pain fibers or nerve endings,
|
|
|
whereas the parietal pleura does have |
sensory pain fiber
|
|
|
Therefore irritation of the parietal pleura causes |
pain with each breath
|
|
|
The space between the pleural layers is called the |
intrapleural space
|
|
|
Normally this space contains |
20 to 25 mL of fluid
|
|
|
This fluid serves two purposes: |
(1) It provides lubrication, allowing the pleural layers to slide over each other during breathing
and (2) It increases cohesion between the pleural layers, thereby facilitating expansion of the pleurae and lungs during inspiration |
|
|
Fluid drains from the pleural space by the |
lymphatic circulation
|
|
|
Several pathologic conditions may cause the accumulation of greater amounts of fluid, termed |
a pleural effusion
|
|
|
Pleural fluid may accumulate because of |
blockage of lymphatic drainage (from malignant cells) or because of an imbalance between intravascular and oncotic fluid pressures, as in heart failure
|
|
|
Purulent pleural fluid with bacterial infection is called |
empyema
|
|
|
The diaphragm is |
the major muscle of respiration
|
|
|
During inspiration the diaphragm |
contracts, increasing intrathoracic volume and pushing the abdominal contents downward
|
|
|
At the same time the external intercostal muscles and scalene muscles contract |
increasing the lateral and anteroposterior (AP) dimension of the chest
|
|
|
This causes the size of the thoracic cavity to |
increase and intrathoracic pressure to decrease, so air enters the lungs
|
|
|
The diaphragm is made up of |
two hemidiaphragms, each innervated by the right and left phrenic nerves
|
|
|
The phrenic nerves arise from |
the spinal cord between C3 and C5, the third and fifth cervical vertebrae
|
|
|
Injury to the phrenic nerve results in |
hemidiaphragm paralysis on the side of the injury
|
|
|
Complete spinal cord injuries above the level of |
C3 result in total diaphragm paralysis and dependence on a mechanical ventilator
|
|
|
Ventilation involves
|
inspiration, or inhalation (movement of air into the lungs), and expiration, or exhalation (movement of air out of the lungs)
|
|
|
Air moves in and out of the lungs because |
intrathoracic pressure changes in relation to pressure at the airway opening
|
|
|
Contraction of the diaphragm and intercostal and scalene muscles increases |
chest dimensions, thereby decreasing intrathoracic pressure
|
|
|
Gas flows from |
an area of higher pressure (atmospheric) to one of lower pressure (intrathoracic)
|
|
|
When dyspnea (shortness of breath) occurs, neck and shoulder muscles |
can assist the effort
|
|
|
Some conditions may limit diaphragm or chest wall movement and cause the patient to breathe with |
smaller tidal volumes
|
|
|
What are some condition that can cause a smaller tidal volume |
phrenic nerve paralysis, rib fractures, neuromuscular disease
|
|
|
As a result,smaller tidal volumes |
the lungs do not fully inflate, and gas exchange is impaired
|
|
|
In contrast to inspiration, expiration is |
passive
|
|
|
Elastic recoil is |
the tendency for the lungs to relax after being stretched or expanded
|
. |
|
The elasticity of lung tissue is due to the |
elastin fibers found in the alveolar walls and surrounding the bronchioles and capillaries
|
|
|
The elastic recoil of the chest wall and lungs allows |
the chest to passively decrease in volume
|
|
|
Intrathoracic pressure rises, causing |
air to move out of the lungs
|
|
|
Exacerbations of asthma or chronic obstructive pulmonary disease (COPD) cause |
expiration to become an active, labored process
|
|
|
Abdominal, intercostal, and accessory muscles scalene, trapezius assist in |
expelling air during labored breathing
|
|
|
Compliance (distensibility) is
|
a measure of the ease of expansion of the lungs
|
|
|
This is a product of |
the elasticity of the lungs and the elastic recoil of the chest wall
|
|
|
When compliance is decreased, |
the lungs are more difficult to inflate
|
|
|
Examples include conditions that increase fluid in the such as |
lungs pulmonary edema, ARDS, Pneumonia
|
|
|
Conditions that make lung tissue less elastic or distensible are |
pulmonary fibrosis sarcoidosis
|
|
|
Condition that restrict lung movement |
pleural effusion
|
|
|
Compliance is increased when |
there is destruction of alveolar walls and loss of tissue elasticity, as in COPD
|
|
|
Oxygen and carbon dioxide move back and forth across the alveolar-capillary membrane by
|
diffusion
|
|
|
Diffusion continues until |
equilibrium is reached
|
|
|
The lungs’ ability to oxygenate arterial blood adequately is assessed by |
examination of the partial pressure of oxygen in
arterial blood (PaO2) and arterial oxygen saturation (SaO2) |
|
|
Oxygen is carried in the blood in two forms: |
dissolved oxygen and hemoglobin-bound oxygen
|
|
|
The PaO2 represents |
the amount of oxygen dissolved in the plasma and is expressed in millimeters of mercury (mm Hg)
|
|
|
The SaO2 is the |
amount of oxygen bound to hemoglobin in comparison with the amount of oxygen the hemoglobin can carry
|
|
|
The SaO2 is expressed as a |
percentage
|
|
|
if the SaO2 is 90%, this means |
that 90% of the hemoglobin attachments for oxygen have oxygen bound to them
|
|
|
Two methods are used to assess the efficiency of gas transfer in the lung and tissue oxygenation: analysis of
|
arterial blood gases (ABGs) and pulse oximetry
|
|
|
ABGs are measured to |
determine oxygenation status and acid- base balance
|
|
|
ABG analysis includes measurement of the |
PaO2, PaCO2, acidity (pH), and bicarbonate (HCO −) in arterial blood
|
|
|
The SaO2 is either calculated or measured during |
ABG analysis
|
|
|
Blood for ABG analysis can be obtained by |
arterial puncture or from an arterial catheter,
Blood for ABG analysis Usually COMES FROM the |
radial or femoral artery
Both techniques allow |
|
Continuous intraarterial blood gas monitoring is also possible via |
a fiberoptic sensor or an oxygen electrode inserted into an arterial catheter
|
|
|
An arterial catheter permits |
ABG sampling without repeated arterial punctures
|
|
|
The normal PaO2 decreases with |
advancing age
|
|
|
It also varies in relation to the distance |
above sea level
|
|
|
At higher altitudes the barometric pressure is lower, resulting in |
a lower inspired oxygen pressure and a lower PaO2
|
|
|
For the patient with a normal or near-normal cardiac status, an assessment of
|
PaO2 or SaO2 is usually sufficient to determine the level of oxygenation
|
|
|
The patient with impaired cardiac output or hemodynamic instability may have |
Inadequate tissue oxygen delivery or abnormal oxygen consumption
|
|
|
The amount of oxygen delivered to the tissues or consumed can be |
calculated
|
/ |
|
Blood drawn from a PA catheter is termed a mixed venous blood gas sample because |
it consists of venous blood that has returned to the heart and “mixes” in the right ventricle
|
|
|
When tissue oxygen delivery is inadequate or when inadequate oxygen is transported to the tissues by the hemoglobin WHAT HAPPENS, |
the PvO2 and SvO2 fall
|
|
|
Arterial oxygen saturation can be monitored noninvasively and continuously using a pulse oximetry probe on the
|
finger, toe, ear, bridge of the nose
|
|
|
The abbreviation SpO2 is used to |
indicate the oxygen saturation of hemoglobin as measured by pulse oximetry SpO2 and heart rate are displayed on the monitor as digital readings
|
|
|
Pulse oximetry is particularly valuable in intensive care and perioperative situations, in which |
sedation or decreased consciousness might mask hypoxia
|
|
|
SpO2 is assessed with each |
routine vital sign check in many inpatient areas
|
|
|
Changes in SpO2 can be |
detected quickly and treated
|
|
|
Oximetry is also used during |
exercise testing and when adjusting flow rates during long-term oxygen therapy
|
|
|
Values obtained by pulse oximetry are less accurate if |
the SpO2 is less than 70%
|
|
|
At this level the oximeter may display a value that is |
±4% of the actual value
|
|
|
For example, if the SpO2 reading is 70%, the actual value can range from |
66% to 74%
|
|
|
Pulse oximetry is also inaccurate if |
hemoglobin variants are present carboxyhemoglobinmethemoglobin
|
|
|
Other factors that can alter the accuracy of pulse oximetry include |
motion low perfusion anemia cold extremities bright fluorescent lights intravascular dyes thick acrylic nails dark skin color
|
|
|
If there is doubt about the accuracy of the SpO2 reading, |
obtain an ABG analysis to verify the results
|
|
|
Oximetry can also be used to monitor SvO2 |
via a PA catheter
|
|
|
A decrease in SvO2 suggests that |
less oxygen is being delivered to the tissues or that more oxygen is being consumed
|
|
|
Changes in SvO2 provide an |
early warning of a change in cardiac output or tissue oxygen delivery
|
|
|
Normal SvO2 is |
60% to 80%
|
|
|
Carbon dioxide can be monitored using
|
transcutaneous CO2 (PTCCO2) and end-tidal CO PETCO2) (capnography)
|
|
|
Transcutaneous measurement of CO2 is a noninvasive method of |
estimating arterial pressure of CO2 (PaCO2)
using an electrode placed on the skin |
|
|
PETCO2 is the noninvasive measurement of |
alveolar CO2 at the end of exhalation when CO2 concentration is at its peak
|
|
|
It is used to monitor and assess trends in the patient’s |
ventilatory status
|
|
|
Expired gases are sampled from the patient’s airway and are analyzed by a |
CO2 sensor that uses infrared light to measure exhaled CO2
|
|
|
The sensor may be attached to an |
adaptor on the endotracheal tube or the tracheostomy tube
|
|
|
A nasal cannula with a sidestream capnometer can be used in patients without |
an artificial airway
|
|
|
Capnography is usually presented as a |
graph of expiratory CO2 plotted against time
|
|
|
In the past, capnography was used mainly |
intraoperatively, postoperatively, and in critical care units
|
|
|
Today’s monitors are portable and practical for use on |
inpatient units and emergency departments
|
|
|
Measurement of oxygen saturation (oximetry) is primarily used to assess |
for hypoxia
|
|
|
CO2 monitoring assesses for |
hypoventilation
|
|
|
The use of both measures together is important in determining patients’ |
oxygenation and ventilatory status
|
|
|
A chemoreceptor is a
|
receptor that responds to a change in the chemical composition (PaCO2 and pH) of the fluid around it
|
|
|
Central chemoreceptors are located in the |
medulla and respond to changes in the hydrogen ion (H+) concentration
|
|
|
An increase in the H+ concentration (acidosis) causes the medulla to |
increase the respiratory rate and tidal volume (VT)
|
|
|
A decrease in H+ concentration (alkalosis) has |
the opposite effect
|
|
|
Changes in PaCO2 regulate ventilation primarily by |
their effect on the pH of the cerebrospinal fluid
|
|
|
When the PaCO2 level is increased, |
more CO2 is available to combine with H2O and form carbonic acid (H2CO3)
|
|
|
This lowers the cerebrospinal fluid pH and stimulates an increase in |
respiratory rate
|
|
|
The opposite process occurs with a decrease in |
PaCO2 level
|
|
|
Peripheral chemoreceptors are located in the |
carotid bodies at the bifurcation of the common carotid arteries and in the aortic bodies above and below the aortic arch
|
|
|
The peripheral chemoreceptors respond to decreases in |
PaO2 and pH and to increases in PaCO2
|
|
|
These changes also stimulate the |
respiratory center
|
|
|
In a healthy person an increase in PaCO2 or a decrease in pH causes an |
immediate increase in the respiratory rate
|
|
|
The PaCO2 does not vary more than about |
3 mm Hg if lung function is normal
|
|
|
Conditions such as COPD alter lung function and may result in |
chronically elevated PaCO2 levels
|
|
|
In these instances the patient is relatively |
insensitive to further increases in PaCO2 as a stimulus to breathe and may be maintaining ventilation largely because of a hypoxic drive from the peripheral chemoreceptors
|
|
|
Mechanical receptors (juxtacapillary and irritant) are located in the
|
lungs, upper airways, chest wall, and diaphragm
|
|
|
They are stimulated by a variety of physiologic factors, such as |
irritants, muscle stretching, and alveolar wall distortion
|
|
|
Signals from the stretch receptors aid in the control of |
respiration
|
|
|
As the lungs inflate, |
pulmonary stretch receptors activate the inspiratory center to inhibit further lung expansion
|
|
|
This is termed the Hering-Breuer reflex, and it prevents |
overdistention of the lungs
|
|
|
Impulses from the mechanical sensors are sent through the |
vagus nerve to the brain
|
|
|
Juxtacapillary (J) receptors are believed to cause |
the rapid respiration (tachypnea) seen in pulmonary edema
|
|
|
These receptors are stimulated by |
fluid entering the pulmonary interstitial space
|
|
|
Respiratory defense mechanisms are efficient in protecting the lungs from
|
inhaled particles, microorganisms, and toxic gases
|
|
|
The defense mechanisms include |
filtration of air, the mucocili- ary clearance system, the cough reflex, reflex bronchoconstric- tion, and alveolar macrophages
|
|
|
Nasal hairs
|
filter inspired air
|
|
|
Below the larynx, the movement of mucus is accomplished by the
|
mucociliary clear- ance system, commonly referred to as the mucociliary escalator
|
|
|
This term is used to indicate the relationship between the |
secre- tion of mucus and the ciliary activity
|
|
|
Mucus is continuously secreted at a rate of about |
100 mL/day by goblet cells and sub- mucosal glands
|
|
|
It forms a mucous blanket that contains |
the impacted particles and debris from distal lung areas
|
|
|
The small amount of mucus normally secreted is |
swallowed without being noticed
|
|
|
Secretory immunoglobulin A (IgA) in the mucus helps |
protect against bacteria and viruses
|
|
|
Cilia cover the airways from the level of the |
trachea to the respiratory bronchioles
|
|
|
Each ciliated cell contains approximately 200 cilia, which beat rhythmically about |
1000 times per minute in the large airways, moving mucus toward the mouth
|
|
|
The ciliary beat is slower further down the |
tracheobronchial tree
|
|
|
As a consequence, particles that penetrate more deeply into the airways |
are removed less rapidly
|
|
|
Ciliary action is impaired by |
dehydration
smoking inhalation of high oxygen concentrations infection and ingestion of drugs such as atropine, anesthetics, alcohol, or cocaine |
|
|
Patients with COPD and cystic fibrosis have |
repeated lower respiratory tract infections
|
|
|
Cilia are often destroyed during these infections, resulting in |
impaired secretion clearance
a chronic productive cough and chronic colonization by bacteria, which leads to frequent respiratory tract infections |
|
|
The cough is a
|
protective reflex action that clears the airway by a high-pressure, high-velocity flow of air
|
|
|
It is a backup for |
mucociliary clearance, especially when this clearance mechanism is overwhelmed or ineffective
|
|
|
Coughing is only effective in removing secretions |
above the subsegmental level (large or main airways)
|
|
|
Secretions below this level must be moved upward by the |
mucociliary mechanism before they can be removed by coughing
|
|
|
Reflex bronchoconstriction is another |
defense mechanism
|
|
|
In response to the inhalation of large amounts of irritating substances |
the bronchi constrict in an effort to prevent entry of the irritants
|
|
|
A person with hyperreactive airways, such as a person with asthma, may experience |
bronchoconstriction after inhalation of triggers such as cold air, perfume, or other strong odors
|
|
|
Because ciliated cells are not found below the level of the respiratory bronchioles, the primary defense mechanism at the alveolar level is |
alveolar macrophages
|
|
|
Alveolar macrophages rapidly |
phagocytize inhaled foreign par- ticles such as bacteria
|
|
|
The debris is moved to the level of the bronchioles for removal by the |
cilia or removed from the lungs by the lymphatic system
|
|
|
Particles that cannot be adequately phagocytized tend to |
remain in the lungs for indefinite periods and can stimulate inflammatory responses
|
|
|
Because alveolar macrophage activity is impaired by cigarette smoke, the smoker who is employed in an occupation with heavy dust exposureis at an especially high risk for |
lung disease
|
|
|
Age-related changes in the respiratory system can be divided into |
alterations in structure, defense mechanisms, and respiratory control
|
|
|
Structural changes include |
calcification of the costal cartilages, which can interfere with chest expansion
|
|
|
The outward curvature of the spine is marked, espe-cially with |
osteoporosis, and the lumbar curve flattens
|
|
|
There- fore the chest may appear barrel shaped, and the older person may need to use |
accessory muscles to breathe
|
|
|
Respiratory muscle strength progressively declines after |
age 50
|
|
|
Overall, the lungs in the older adult are |
harder to inflate
|
|
|
Many older adults lose |
subcutaneous fat, and bony prominences are pronounced
|
|
|
Within the lung, the number of func- tional alveoli |
decreases, and they become less elastic
|
|
|
Small airways in the lung bases close earlier in |
expiration
|
|
|
As a con- sequence, more inspired air is distributed to the lung apices and ventilation is less well matched to perfusion, lowering |
the PaO2
|
|
|
Therefore older adults have less tolerance for |
exertion, and dyspnea can occur if their activity exceeds their normal exercise
|
|
|
Respiratory defense mechanisms are less effective because of |
a decline in both cell-mediated and humoral immunity (ability to produce antibodies)
|
|
|
The alveolar macrophages are less effective at |
phagocytosis
|
|
|
An older patient has a less forceful |
cough and fewer and less functional cilia
|
|
|
Mucous membranes tend to be |
drier
|
|
|
Retained mucus predisposes the older adult to |
respiratory tract infections
|
|
|
Formation of secretory IgA, |
an important defense mechanism, is diminished
|
|
|
Swallowing is slower because of |
transit time in the pharyngeal area, and there is reduced sensation in the pharynx
|
|
|
If the older adult patient has a super- imposed neurologic condition, |
aspiration is likely
|
|
|
Respiratory control is altered, resulting in a more |
gradual response to changes in blood oxygen or carbon dioxide level
|
|
|
The PaO2 drops to a lower level and the PaCO2 |
rises to a higher level before the respiratory rate changes
|
|
|
The extent of these changes in people of the same age |
varies greatly
|
|
|
The older adult who has a significant |
smoking history, is obese, and is diagnosed with a chronic illness is at greatest risk of adverse outcomes
|
|
|
In addition, the abrupt changes in direction of airflow that occur as air moves through the nasopharynx and larynx increase air turbulenceThis causes
|
particles and bacteria to contact the mucosa lining these structures Most large particles (greater than 5 μm) are less dangerous because
|
|
|
A catheter positioned in the pulmonary artery, termed a pulmonary artery (PA) catheter, is used for
|
mixed venous sampling
|
|
|
The overall direction of movement is from
|
the area of higher concentration to the area of lower concentration
|
|