Protection from inhaled pathogen & irritating substances
Distinguish between external and internal respiration.
-during expiration muscles relax, elastic recoil returns lung, rib cage, and diaphragm, to their relaxed position(passive expiration)
-during inspiration diaphragm contract, pushing down, rib cage moves out and upward via muscles, and lungs expand, also, P inside lung must be lower than atmospheric P for air to move into alveoli
List and describe factors influencing air flow to and from lungs.
air flow moves from higher pressure to lower pressure
muscular pump creates pressure gradients
resistance to flow, diameter of tubs
Identify the the major components of the respiratory system, list in order from environment to alveoli.
Oral and nasal cavity-->pharynx-->larynx-->trachea-->L & R primary bronchus-->secondary bronchus-->bronchioles-->alveoli
Distinguish between partial and visceral pleura. Note where pleural cavity exist.
Explain what "conditioning" air refers to.
Warms the air to body temperature so alveoli aren't damaged by cold air
humidifies air to 100% so epithelium doesn't dry out
Filters out foreign material so viruses and bacteria don't reach the alveoli
Name the cell types of alveoli and their function.
type II alveolar cells are smaller but thicker, synthesize surfactant which aids in the expansion of lungs by mixing with the thin fluid lining alveoli.
type I alveolar cells
(95%), larger, so thin which allows gases to diffuse rapidly
Describe how Dalton's & Boyles's Laws influence breathing.
Dalton's Law states that total pressure of a mixture of gases is the sum of the pressures of the individual gases. The pressure of an individual gas mixture os known as the partial pressure of gas (Pgas).
Partial pressure of gas=Patm x % of gas in atm
Boyles's Law expresses the inverse relationship between pressure and volume. as pressure ↑, volume ↓