Structure of Respiratory Lobule (3)
Respiratory bronchiole, alveoli, pulmonary capillaries
Alveolar sac is separated by septa which contains
Capillary Network-blood is exposed to air on both sides
Type I cells are for?
Type II cells are for?
Surfactant Production which keep alveoli patent
How does air get into lungs? (hint: Intrapulmonary or alveolar pressure, intrapleural and intrathoracic pressure)
Intrapulmonary pressure or alveolar pressure is the same as atmospheric pressure
Intrapleural (-4) and Intrathoracic pressure are negative
Which anatomical structure plays a major role in ventilation?
Which other muscles paly a role in ventilation besides the diaphragm?
Which muscles are not involved in normal ventilation?
What is lung compliance?
It refers to the ease with which the lungs can be inflated
Which 2 fibers determine lung compliance?
Elastin and Collagen Fibers
What is the role of surfactant?
Prevents the lungs from collapsing
Describe Tidal, Inspiratory Reserve, Expiratory Reserve, and Residual
Tidal is normal respiration; 500mL
Inspiratory Reserve- max air inspired at the end of nl respiration
Expiratory Reserve- max air exhaled after nl expiration
Residual Volume- the amt. of air that can not be breathed in or out of the lung with maximal effort
Total Lung Capacity
Functional Residual Capacity
- Total lung capacity- amt of max air inspired
- Vital Capacity- max air exhaled after max inspiration
- Inspiratory Capacity- max air inhaled starting from resting inspiratory position
- Functional residual Capacity- the amt of air remaining after nl respiration
What is FVC?
the air you can breathe out
What is FEV1?
The amount you breathe out in 1 min
A decrease in FEF (25-75%) is mainly a problem with which airways?
If you have a decrease in FEV1/FVC, which lung d/o is this indicative of?
Obstructive (Asthma, COPD, Bronchiectasis, CF)
If the FEV1/FVC ratio is nl, but FVC and FEV1 are decreased, what lung d/o is this indicative of?
Restrictive (Sarcoidosis, Occupational, Interstitial)
Ventilation and Perfusion
Describe gravity's role on the lung and intrapleural pressure at the apex. What does this result in (hint: alveoli)
Gravity when standing exerts a downward pull on the lungs creating a neg intrapleural pressure at the apices which expands the alveoli making them less compliant
Ventilation and Perfusion
Where is blood flow less? In the upper or base of the lung?
What can cause a decrease in diffusion of gases?
A thick septa
Matching of ventilation and perfusion depends on?
anatomical dead space (the air in trachea and large/med bronchioles)
What is alveolar dead space?
The air that doesn't partake in gas exchange
What is physiological dead space?
Anatomic + Alveolar
What is shunting?
Blood moving from R to L without being oxygenated
Mismatching of ventilation and perfusion is do to what (2)?
What could this lead to/
dead air space and shunting, which can lead to cyanosis
Pneumonia is an infection due to inflammation of the parenchymal structures such as?
The alveoli and bronchioles. It is not an airway problem
Pneumonia can be either infectious or non infectious. Give examples
- Infectious-bacterial or viral
- Non infectious- gastric aspiration
How are pneumona bacterial infections caused (4)?
Which is the most common?
- Inhalation from air-MOST COMMON
- Aspiration from previously colonised airway-if host defense is down the bacteria can spread from colonization
- Direct spread- injury to chest wall/trauma
- Hematogenous- through the blood