Flashcards in Respiratory System Deck (113)
At a constant temperature, the amount of a gas that dissolves in a liquid is directly proportional to the partial pressure of the gas above the liquid
How much of a gas will dissolve in a liquid at a given partial pressure also depends on what?
Solubility of the gas
How many more times is CO2 more soluble than O2?
As compared to atmospheric gas, alveolar gas contains what amounts of O2?CO2?H20?
less, more, and more
Gas exchange across respiratory membrane
What factors influence external respiration?
thickness and SA of respiratory membrane, Partial pressure gradients and gas solubilities
What is the average thickness of the respiratory membrane in healthy lungs?
0.5-1 m thick
Gas exchange between systemic capillaries and tissue cells
What occurs during internal respiration?
O2 moves from blood into tissue and CO2 moves from tissues into blood
Which 2 ways is O2 transported in the blood?
1. Bound to Hb
2. Dissolved in plasma
Reduced Hb (deoxyHb)
HB that has released O2
Define. Hb saturation
extent to which Hb is combined with O2
How many O2 are bound to heme to be considered to be fully saturated?
How manyO2 are bound to heme to be considered partially saturated?
What describes the relationship between the local Po2 and Hb saturation?
oxygen-Hb dissociation curve
In blood leaving lungs when the P02 is at 100 mmHg how saturated is Hb?
At resting tissues, what are the values for partial pressure of O2 and Hb saturation?
Po2= 40 mmHg
Hb saturation: 75%
Which 4 factors affect Hb at a given Po2?
temperature, pH, 2-3,BPG, and Pco2
What are the effects of the increase of temperature, H+, Pco2, or BPG?
Hb unloads O2 more easily
Curve shifts to the right
%Hb saturation ill be lower
What are the functions of the respiratory system?
to obtain O2 for use by body cells and to eliminate CO2 that cells produce
What are the 4 processes in respiration?
1. Pulmonary ventilation
2. External Respiration
3. Transport of gases
4. Internal Respiration
What are the major organs of the respiratory system?
nose, nasal cavity, paranasal sinuses, pharynx, larynx, trachea, bronchi, lungs and alveoli
Site of gas exchange
All other respiratory passageways that cleanse, and humidify and warm air
Which organs are a part of the respiratory zones?
respiratory bronchioles, alveolar ducts and alveoli
Provides airway for respiration, filters inspired air, moisten and warms inspired air, houses olfactory receptors
Opens to exterior via nostrils
Continuous with pharynx via posterior nasal apertures
Bony structure in the nasal cavity