Exam 5 4.20 Pulmonary.Part 1 Flashcards
1
Q
2 structures in the upper airways (conducting airways)
A
- Nasopharynx
- Oropharynx
2
Q
2 things to know about the Larynx
A
- Connects upper and lower airways
- site of vocal cords
3
Q
3 structures of the Lower airways- and general description of each
A
- Trachea – branches into 2 main airways at the carina, R and L bronchi
- Bronchi – enter lung at the hilum of each lung
- Terminal bronchioles – tree-like division of bronchi into bronchioles, until the smallest ones connect to the alveoli
4
Q
3 structures of the Gas-exchange airways
A
- Respiratory bronchioles
- Alveolar ducts
- Alveoli
5
Q
Two types of Epithelial cells in Alveoli
A
- Type I alveolar cells - Alveolar structure
- Type II alveolar cells - Surfactant production
6
Q
True or False: Pulmonary circulation has a higher pressure than the systemic circulation
A
False
It has a lower pressure
7
Q
One-third of pulmonary vessels are filled with what?
A
Filled with blood at any given time
- This allows space for extra blood during ↑ cardiac activity, keeping pulmonary pressure stable
8
Q
Where does Pulmonary artery enter the lungs?
A
Pulmonary artery divides and enters the lung at the hilum
9
Q
What does each bronchus and bronchiole have?
A
an accompanying artery or arteriole
10
Q
3 things to know about alveolocapillary membrane
A
- Formed by the shared alveolar and capillary walls
- Gas exchange occurs across this membrane
- Any disorder that thickens this membrane impairs gas exchange
11
Q
3 basic points about Pulmonary veins and circulation
A
- Each drains several pulmonary capillaries
- Dispersed randomly throughout the lung
- Leave the lung at the hila and enter the left atrium
12
Q
What makes up the chest wall?
A
- Skin, ribs, and intercostal muscles
- Function is protection and muscular support for breathing
- Thoracic cavity
- Encases the lungs
13
Q
What makes up the pleura?
A
- Is a serous membrane
- Parietal and visceral layers
- Pleural space (cavity)
- Pleural fluid
14
Q
How much Pleural fluid do we have and why do we have it?
A
about 1 ½ teaspoons around each lung, just enough to provide surface tension between parietal and visceral layers
15
Q
Define Ventilation
A
Mechanical movement of gas or air into and out of the lungs
16
Q
What is Minute volume and some norms?
A
- Ventilatory rate multiplied by the volume of air per breath (tidal volume)
- Average breaths per minute is ~ 14-18
- Average tidal volume is 8-10 ml/kg of weight (book uses 500 ml as an average)
Example: For a 70 kg (154 lb.) person, 15 breaths/minute
70 X 10 X 15 = 10,500 ml = 10.5 L
17
Q
Major muscles of inspiration
A
- Diaphragm
- External intercostals – “hands in front pockets”
18
Q
Accessory muscles of inspiration
A
- Sternocleidomastoid muscle
- Scalene muscles
19
Q
Accessory muscles of expiration
A
- Abdominal intercostal muscles
- Internal intercostal muscles – “hands in back pockets”
- There are no major muscles of expiration –it’s a passive event
20
Q
What is the Function of surfactant in Alveolar surface tension and ventilation?
How does it work?
When things go wrong….
A
- reduces surface tension
- liquid molecules exposed to air tend to adhere to each other
- Lack of surfactant is a major reason that premature babies require ventilator support
21
Q
Why are there elastic properties of the lung and chest wall?
A
- maintains normal negative pressure of pleural space
- Elastic recoil – lungs will return to resting state after inspiration, thereby permitting passive expiration
- Compliance – relative ease of lung “stretching”
- Volume change per unit of pressure change
- Determined by alveolar surface tension and elastic recoil
22
Q
Changes with elasticity in lung that occur with aging and pathology
A
- ↑ with normal aging and disorders such as emphysema; stretch too easily
- ↓ in ARDS (acute respiratory distress syndrome, pneumonia, fibrosis, pulmonary edema); stiffer
23
Q
What determines Airway resistance?
A
Determined by size of airway and density, viscosity, velocity of the gas
24
Q
Some causes of increased airway resistance
A
- Bronchoconstriction
- mucus
- inflammation
25
Muscular effort ↑ in the work of breathing with these 3 issues
1. Lung compliance ↓ (fibrosis, pulmonary edema)
2. Chest wall compliance ↓ (obesity, spinal deformity)
3. Airways are obstructed by spasm or mucous (asthma, acute bronchitis)
26
What is measured when taking Measurement of Gas Pressure?
* Pressure and volume measurements made in pulmonary function testing labs specify the temperature and humidity of gases at the time of measurement
* Air is 78% N, 21% O2, rest is water vapor, CO2, minute concentrations of noble gases
27
Points about ventilation and perfusion (6)
* Distribution of ventilation and perfusion – need to have an approximately even distribution of gas (ventilation) and blood (perfusion) in all parts of the lung
* Gravity and alveolar pressure – the most dependent part of the lung will have the best perfusion (fig. 25-14, p. 671)
* If gas pressure in alveoli exceeds the blood pressure in the capillary, the capillary collapses and flow ceases
* Ventilation-perfusion ratio (V/Q ratio)- Perfusion exceeds ventilation in the bases, and ventilation exceeds perfusion in the apices
* Normal V/Q is 0.8, with perfusion exceeding ventilation
* Body position changes the areas of perfusion and ventilation
28
Location of O2 transport and determinants of arterial oxygenation
* Diffusion across the alveolocapillary membrane – takes ~0.75 second
* Determinants of arterial oxygenation:
* Hemoglobin binding – O2 moves to the RBCs and binds with hemoglobin
* Oxygen saturation (Sao2) is % of available hemoglobin bound to O2; measured with oximeter
* Important measure of pulmonary function
29
Pic of the various volumes and whatnot in lung capacity
30
What is spirometry?
how much air inhaled, and exhaled, and how quickly
31
What is Diffusion capacity?
how much O2 travels from alveoli to the blood stream, measuring carbon monoxide
32
What is Residual volume?
amount of air left in lungs after forced expiration – is estimated, can’t be directly measured
33
What is Functional reserve capacity (FRC)?
amount of air left in lung after a normal expiration
34
What is Total lung capacity?
inspiratory capacity + functional residual capacity; volume of air in the lungs at the end of a maximal inspiration
35
What is measured in Arterial blood gas analysis? (4)
* O2
* CO2
* arterial O2 saturation
* pH
36
Tests and measures used to evaluate pulmonary function (8)
* Spirometry
* Pulmonary Function Testing (PFT)
* Diffusion capacity
* Residual volume
* Functional reserve capacity (FRC)
* Total lung capacity
* Arterial blood gas analysis
* Chest radiographs
37
Basic meaning of Obstructive and Restrictive
Obstructive - trouble getting air out of lungs
Restrictive – trouble getting air in
38
Restrictive lung diseases (10)
* Pulmonary Fibrosis
* Inhalation disorders- obesity
* Pneumoconiosis- coal miners
* Allergic alveolitis
* Lung Cancer
* Scleroderma
* Cystic Fibrosis
* Scoliosis
* Ankylosing Spondylitis
* Neuromuscular Disorders
39
Obstructive lung diseases (3)
* Emphysema
* Chronic Bronchitis
* Asthma
40
General info about restrictive diseases (4)
* Lungs stiffer, less compliant
* Requires ↑ transpulmonary pressure to expand the lung
* All lung volumes and capacities ↓; degree will depend on source of restriction
* Patients experience respiratory muscle fatigue, overuse, and failure
41
Signs of Restrictive Lung Disease (7)
* Tachypnea
* Hypoxemia
* ↓breath sounds
* ↓lung volumes and capacities
* Cor pulmonale (R sided heart failure)
* Altered chest radiograph (varies according to disease)
* Pulmonary hypertension
42
Symptoms of Restrictive Lung Disease (4)
* Dyspnea
* Cough
* Weight loss
* Muscle wasting
43
Changes in lung volume measures in restrictive diseases
Decreased:
* TLC
* FEV1
* FVC
* FRC
* IC
FEV1/FVC ratio remains normal
44
Supportive Measures for Restrictive Lung Disease (4)
* Supplemental O2 if Pao2 ≤ 55 mm Hg or ≤ 59 mm Hg with signs of right-sided heart strain or polycythemia
* Antibiotic therapy for secondary infections
* Interventions to promote adequate ventilation (CPAP, BiPAP, ventilator)
* Good nutritional support
45
General Info about Obstructive Lung Diseases (6)
* Expiratory airflow is obstructed
* ↑ residual volume (physiologic dead space)
* Retained secretions
* Inflammation of mucosal lining of airway walls
* Bronchial constrictions related to ↑tone or spasm of bronchial smooth muscle
* Weakening of the support structure of airway walls
46
Signs/Symptoms of Obstructive Lung Diseases
* Elevation of shoulder girdle
* Horizontal ribs
* Barrel-shaped thorax (↑ A-P diameter)
* Low, flattened diaphragm
* Spirometry is better measure of OLD than CXR
* Orthopnea- dyspnea lying flat
* Paroxysmal nocturnal dyspnea- night time coughing or SOB that awakens patient
47
Emphysema vs. Chronic bronchitis
_Emphysema form_ – destruction of alveolar walls, enlargement of air spaces distal to terminal bronchioles
* Smoking is a major determinant
_Chronic bronchitis_ – presence of chronic productive cough for 3 months in each of 2 successive years (other diseases ruled out) – hypersecretion and hypertrophy of submucosal glands
*Most COPD patients have mixed pathology*
48
Pink Puffers vs. Blue Bloaters
49
Pic with info about Emphysema – “Pink Puffer”
50
Pic with info about Chronic Bronchitis – “Blue Bloater”
