Respiratory Dysfunction Flashcards
What is tidal volume?
Amount of air that moves in and out of the lungs with each breath, 500 mL
What is residual volume?
Volume of air remaining in the lungs after maximal expiration, 1200 mL
What is the inspiratory reserve volume (IRV)
Maximum amount of air that can be inspired after reaching the end of a normal, quiet inspiration, 3000 mL
What is the expiratory reserve volume, (ERV)
Maximum amount of air that can be exhaled after reaching the end of a normal, quiet inspiration, 1100 mL
What is vital capacity
amount of air that can be exhaled from the point of maximal inspiration, 4600 mL
What is the formula for vital capacity?
IRV + TV + ERV
What is the inspiratory capacity
The amount of air a person can breathe in beginning at the normal expiratory level, 3500/3600 mL
What is the formula for inspiratory capacity
TV + IRV
What is the total lung capacity?
sum of all volumes in the lungs, 5800/6000 mL
What is the ratio for ventilation-perfusion?
V/Q
What is a low VQ
Shunting= decreased ventilation, normal perfusion
What is a high VQ
Dead air= normal ventilation, decreased perfusion
What are the mechanics of breathing?
Rise in carbon dioxide (CO2) stimulates medulla oblongata, efferent nerve impulses to diaphragm and intercostal muscles to contract.
Negative pressure in lungs which allows air to enter airways and alveoli. The lungs fill until the stretch receptors in bronchioles and bronchi send afferent nerve impulses to medulla.
What would happen if the impulses are turned off?
It allows the diaphragm and intercostal muscles to relax, which pushes air out of the alveoli and airways
What are mechanisms of defense?
Constant temperature, Nasal hairs & turbinates, Mucous, Macrophages, Receptors (Irritant Stretch J )
What is the difference between pulmonary ventilation and alveolar ventilation
Pulmonary ventilation is the total exchange of gases between the atmosphere and the lungs.
Alveolar ventilation is the transfer of gases within the gas exchange portion of the lungs
What is surfactant
surface tension-lowering molecules that line the inner surface of the alveoli
What two types of sensors or receptors are involved in automatic regulation of breathing
Chemoreceptors and
Lung and chest wall receptors
What do chemoreceptors do?
monitor blood levels of oxygen, carbon dioxide, and pH, adjust ventilation to meet the changing metabolic needs of the body.
Input –> sensors transmit to the respiratory center —> ventilation adjusts to maintain ABG within normal range
What do lung and chest wall receptors do?
They monitor the status of breathing in terms of airway resistance and lung expansion
What voluntary acts are examples of voluntary regulation of ventilation?
Speaking, blowing, singing
When acts such as speaking, blowing, and singing are initiated by the motor and premotor cortex, what happens?
It causes a temporary suspension of automatic breathing
What is the most common reason for HC visits/ admissions?
Respiratory Tract Infections
What resp tract infections are the 8th leading cause of death in US
Pneumonia and influenza
What is one of the deadliest disease in the world?
Tuberculosis
What is a significant act that can result in respiratory dysfunction and CA
Cigarette smoking
What is pneumonia?
Infection of lower respiratory tract
What is the etiology of pneumonia
bacteria, viruses, fungi, protozoa, parasites
Pneumonia is the nth leading cause of death in US
8th leading cause
What are the risk factors of pneumonia
old age, immunocompromise, alcoholism, LOC, smoking, immobility, endotracheal intubation
What are the routes of infection
Aspiration: aspirate small amounts of organisms that colonized upper airways, inhalation
What are the lines of defenses for pneumonia
Cough reflex: protect against aspiration into tracheobronchial tree
Mucociliary blanket: remove secretions, microorganisms, particles from respiratory tract
Alveolar macrophages: removes microorganisms and foreign particles from the lung
Immune defenses (IgA & IgG/ cell mediated immunity): destroy microorganisms
Pneumonia is an example of what type of VQ
Low VQ because shunting= decreased ventilation but normal perfusion
What are manifestations of bacterial pneumonia
Fever, Rust-colored/ blood-tinged sputum, Productive cough, pleuritic chest pain, chills, crackles
What are manifestations of viral pneumonias
Usu mild and self-limiting, fever,
nonproductive cough, crackles,
wheezing
How is tuberculosis spread
airborne infection, spread by droplet nuclei
What is the primary cell infected with M. tuberculosis
Macrophages
What is the pathogenesis of TB
Macrophages unable to kill organisms so they initiate a cell-mediated immune response that contains the infection, the bacilli multiplies but the infected macrophages degrade them then present antigens to helper T cells. The sensitized helper T cells stimulate macrophages to increase their concentration of lytic enzymes –> boosting ability to kill bacilli. When released, lytic enzymes damage lung tissue.
Why does it take 3 to 6 weeks to become effective?
Development of cytotoxic T cells and macrophages ingest and destroy the bacilli = cell mediated immune response
The cell mediated immune response results in what
development of gray-white circumscribed granulomatous lesion called Ghon focus
What does the Ghon focus contain
Macrophages, T cells, Inactive TB bacteria (tubercle bacilli)
Where is Ghon focus mainly located?
Subpleural area in the upper areas of lower lobes or in the lower are a of the upper lobe
What happens when the number of organisms increase?
hypersensitivity reaction causes central portion of Ghon focus to become necrotic –> creating a soft, white cheese core of dead cells
What also happens at the same time that the Ghon focus becomes necrotic
tubercle bacilli drain in the lymph channels to tracheobronchial lymph nodes of affected lung and cause granulomas
What happens to the Ghon complex (lung lesion and lymph granuloma)
Heal, shrink, scar, visible in xrays
What are the risk factors for TB
malnutrition, old age, immunocompromised, persons in homeless shelters/ crowded and confined conditions
What percentage of people who inhale the organism actually develop TB
~5%
What are the manifestations of active TB
chronic cough with blood tinged sputum, night sweats and fever, unexplained weight loss
What is the diagnosis of active TB
X-rays, isolation, antibiotics, and resistance
What are the manifestations of latent TB
Asymptomatic TB test
Cannot transmit disease
Can turn active tho
What is secondary TB
reinfected or suppressed immune response causes latent TB to reactivate
What creates cavities in secondary TB?
Immediate cell-mediated response walls off infection in airways but bacteria damages tissues in the airways
What are manifestations of secondary TB
Low-grade fevers, ]
Easy fatigability, Anorexia,
Night sweats, and Weight loss
What is consumption in secondary TB
Eventually fatal if untreated
What is the diagnosis of active pulmonary TB
cultures, DNA amplification techniques,
chest radiographs
What is the diagnosis of secondary TB
CT scan
What are the newest diagnostic tests for TB
In vitro assays of CD4+ T cell interferon gamma
Genotyping
Whats the gold standard for diagnosis of TB
Sputum sample (spit) with symptoms like coughing
Why are tests not designed to show what type is present
they test for exposure not dormancy
