Discussion Question
yury12082Chapter 30: Respiratory Tract Infections, Neoplasms, and Childhood Disorders
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Areas Involved in Respiratory Tract Infections
Upper respiratory tract
Nose, oropharynx, and larynx
Lower respiratory tract
Lower airways and lungs
Upper and lower airways
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Common Respiratory Infections
Common cold
Influenza
Pneumonia
Tuberculosis
Fungal infections of the lung
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Factors Affecting the Signs and Symptoms of Respiratory Tract Infections
The function of the structure involved
The severity of the infectious process
The person’s age and general health status
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Transmission of Common Cold
Viral infection of the upper respiratory tract
Rhinoviruses, parainfluenza viruses, respiratory syncytial virus, corona viruses, and adenoviruses
Fingers are the greatest source of spread.
Cough, sneeze
The nasal mucosa and conjunctival surface of the eyes are the most common portals of entry of the virus.
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Question #1
The most common port of entry for cold viruses is _______.
inhalation
small cuts
food
conjunctival surface of the eyes
fingers
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Answer to Question #1
D. conjunctival surface of the eyes
Rationale: Conjunctival surface of the eyes and the nasal mucosa are the most common ports of entry for cold viruses.
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Rhinitis and Sinusitis
Rhinitis
Inflammation of the nasal mucosa
Sinusitis
Inflammation of the paranasal sinuses
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Types of Sinuses #1
Paranasal sinuses
Air cells connected by narrow openings or ostia with the superior, middle, and inferior nasal turbinates of the nasal cavity
Maxillary sinus
Inferior to the bony orbit and superior to the hard palate
Its opening is located superiorly and medially in the sinus, a location that impedes drainage.
Frontal sinuses
Open into the middle meatus of the nasal cavity
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Types of Sinuses #2
Sphenoid sinus
Just anterior to the pituitary fossa behind the posterior ethmoid sinuses
Its paired openings drain into the sphenoethmoidal recess at the top of the nasal cavity.
Ethmoid sinuses
Comprise 3 to 15 air cells on each side, with each maintaining a separate path to the nasal chamber
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Classifications of Rhinosinusitis
Acute rhinosinusitis
May be of viral, bacterial, or mixed viral–bacterial origin
May last from 5 to 7 days up to 4 weeks
Subacute rhinosinusitis
Lasts from 4 weeks to less than 12 weeks
Chronic rhinosinusitis
Lasts beyond 12 weeks
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Allergic Rhinosinusitis
Occurrence
Occurs in conjunction with allergic rhinitis
Mucosal changes are the same as allergic rhinitis.
Symptoms
Nasal stuffiness, itching and burning of the nose, frequent bouts of sneezing, recurrent frontal headache, watery nasal discharge
Treatment
Oral antihistamines, nasal decongestants, and intranasal cromolyn
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Types of Influenza Viruses
Type A
Most common type
Can infect multiple species
Causes the most severe disease
Further divided into subtypes based on two surface antigens: hemagglutinin (H) and neuraminidase (N)
Type B
Has not been categorized into subtypes
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Antiviral Drugs
Amantadine
Rimantadine
Zanamivir
Oseltamivir
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Types of Influenza Vaccinations
Trivalent inactivated influenza vaccine (TIIV)
Developed in the 1940s
Administered by injection
Live, attenuated influenza vaccine (LAIV)
Approved for use in 2003
Administered intranasally
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Pneumonia
Definition
Respiratory disorders involving inflammation of the lung structures (alveoli and bronchioles)
Causes
Infectious agents: such as bacteria and viruses
Noninfectious agents: such as gastric secretions aspirated into the lungs
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Factors Facilitating Development of Pneumonia
An exceedingly virulent organism
A large inoculum
Impaired host defenses
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Classifications of Pneumonias
According to the source of infection
Community-acquired
Hospital-acquired
According to the immune status of the host
Pneumonia in the immunocompromised person
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Tuberculosis
Caused by the mycobacterium, M. Tuberculosis
Outer waxy capsule that makes them more resistant to destruction
Infect practically any organ of the body, the lungs are most frequently involved
Macrophage-directed attack, resulting in parenchymal destruction
Cell-mediated immune response
Confers resistance to the organism
Development of tissue hypersensitivity
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Forms of Tuberculosis
M. tuberculosis hominis (human tuberculosis)
Airborne infection spread by minute droplet nuclei harbored in the respiratory secretions of persons with active tuberculosis
Living under crowded and confined conditions increases the risk for spread of the disease
Bovine tuberculosis
Acquired by drinking milk from infected cows; initially affects the gastrointestinal tract
Has been virtually eradicated in North America and other developed countries
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Positive Tuberculin Skin Test
Results from a cell-mediated immune response
Implies that a person has been infected with M. tuberculosis and has mounted a cell-mediated immune response
Does not mean the person has active tuberculosis
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Laboratory Tests to Diagnose Histoplasmosis
Cultures
Fungal stain
Antigen detection
Serologic tests for antibodies
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Classification and spread of Fungi
Yeasts
Are round and grow by budding
Molds
Form tubular structures called hyphae
Grow by branching and forming spores
Dimorphic Fungi
Grow as yeasts at body temperatures and as molds at room temperatures
Mechanisms of Fungal Spread
Inhalation of spores
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Lung Cancer
Causative factors
Smoking
Asbestos
Familial predisposition
Primary lung tumors (95%) versus bronchial, glandular, lymphoma
Secondary via metastasis
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Categories of Bronchogenic Carcinomas
Squamous cell lung carcinoma (25% to 40%)
Closely related to smoking
Adenocarcinoma (20% to 40%)
Most common in North America
Small cell carcinoma (20% to 25%)
Small round to oval cells, highly malignant
Large cell carcinoma (10% to 15%)
Large polygonal cells, spread early in development
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Question #2
The lungs are a common sight for secondary tumor development. Why?
Due to the highly vascular nature and small capillaries
Due to the fragility of the cells
Due to the rapid replication of type I alveolar cells
Due to dumb luck
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Answer to Question #2
A. Due to the highly vascular nature and small capillaries
Rationale: Due to the highly vascular nature and small capillaries
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Categories of the Manifestations of Lung Cancer
Those due to involvement of the lung and adjacent structures
The effects of local spread and metastasis
The nonmetastatic paraneoplastic manifestations involving endocrine, neurologic, and connective tissue function
Nonspecific symptoms such as anorexia and weight loss
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Question #3
Which of the following involves infection of the entire respiratory track?
Common cold
Pneumonia
Tuberculosis
Cancer
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Answer to Question #3
B. Pneumonia
Rationale: Pneumonia can involve all respiratory tissues, and due to its virulence, is a major health risk.
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Stages of Lung Development
Embryonic period
Pseudoglandular period
Canalicular period
Saccular period
Alveolar period
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Respiratory Disorders in the Neonate
Respiratory distress syndrome
Bronchopulmonary dysplasia
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Respiratory Disorders in Children
Upper airway infections
Viral croup
Spasmodic croup
Epiglottis
Lower airway infections
Acute bronchiolitis
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Impending Respiratory Failure in Infants and Children
Rapid breathing
Exaggerated use of the accessory muscles
Retractions
Nasal flaring
Grunting during expiration
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