where does ventilation take place?
upper respiratory tract
what is the lower respiratory tract responsible for?
PERFUSION: gas exchange
Functions of the respiratory tract
- brings oxygen into the body
- allows for gas exchange
- expels CO2 & other waste products
The upper respiratory tract contains what accessories
- nasal cavity
- oral cavity
- sinuses
- pharynx
- larynx
- trachea
- bronchi
the lower respiratory tract contains what accessories
- smallest bronchioles
- alveoli
where does perfusion occur?
alveoli
what are the layers of the bronchial tubes
- cartilage
- muscle
- epithelial cells
components of the respiratory membrane
- capillary endothelium
- capillary basement membrane
- interstitial space
- alveolar basement membrane
- alveolar epithelium
- surfactant layer
Protective features of the respiratory tract include:
- HAIRS: filter the air
- GOBLET CELLS: produce mucus to trap materials
- CILIA: move trapped material toward throat for swallowing (called ciliary escalator)
- BLOOD SUPPLY: warms air & adds humidity to improve gas movement & gas exchange
- COUGH AND SNEEZES: clear airways
cough reflex (function)
receptors in the trachea and conducting bronchi (super sensitive) are activated….a CNS reflex is initiated
cough causes air to be pushed with great pressure clearing the airway
sneeze reflex (function)
initiated by receptors in nasal cavity
forces foreign material DIRECTLY out of the system
What part of the brain is the control center of breathing?
Medulla Oblongata
PNS & CNS functions in respiration
PNS:
- stimulates the diaphragm during inspiration
CNS:
- bronchodilation
- increased rate & depth of respiration
inhalation
- breathing in
- diaphragm flattens = thoracic volume increases
- lungs expand
- air pressure w/in decreases
exhalation
- breathing out
- diaphragm expands & relaxes
- thoracic volume decreases
- the lungs compress
- air pressure w/in lungs increases
- air rushes out
Upper respiratory conditions include:
- common cold
- seasonal rhinitis
- sinusitis
- pharyngitis & laryngitis
lower respiratory conditions include:
- atelectasis
- pneumonia
- bronchitis
Obstructive disorders include:
- asthma
- COPD
- cystic fibrosis
- respiratory distress syndrome (RDS)
- acute respiratory distress (ARDS)
Atelactasis
definition:
the collapse of once-expanded lung tissue
occurrence:
- outside pressure against alveoli
- most commonly occurs from blockage of the airway
- seen in pt. that have been in car accidents due to air bag
Pneumonia
Definition:
Inflammation of the lungs
Causes:
- bacterial or viral invasion of the tissue
- aspiration of foreign substances into the lower respiratory tract
Symptoms:
- fatigue
- fever
- difficulty breathing
- noisy breath sounds
- poor oxygenation
Bronchitis
Definition:
-narrowed airway during inflammation
Causes:
(acute)
-bacteria, viruses, or foreign materials infect inner layer of bronchi
-narrowed airway
-usually comes from infection such as cold or flu
(chronic)
- doesn’t clear
Asthma
definition:
-REVERSIBLE bronchospasm, inflammation, and hyperactive airways
occurrence:
- triggered by allergens or nonallergic irritants or exercise and emotions
- histamines are released
- cytokine-mediated inflammation, mucous production, & edema = obstruction
NOTE: patients usually have wheezing lung sounds
Extreme Asthma = Status Asthmaticus
Chronic Obstructive Pulmonary Disease (COPD)
definition:
- PERMANENT chronic obstruction
- over inflated lungs & poor gas exchange
causes:
-smoking
-emphysema
loss of elastic tissue of lungs, destruction alveolar walls & hyperinflation of alveoli
-chronic bronchitis
permanent inflammation of airway w/ mucous secretion = edema
cystic fibrosis
- hereditary disease
- very thick secretions in the lungs = destruction of lung tissue
- no cure only medicine to decrease secretion
