Respiratory System Flashcards
What is external respiration?
O2 and CO2 exchange between the whole body and environment.
What is internal respiration?
O2 and CO2 exchange between cells and their environment.
Define the respiratory zone.
Where the exchange between the alveolar gasses and the blood takes place.
Define the conducting zone.
Consisting of the conducting airways. Connects exterior to respiratory zone.
What are the branches of the conducting zone?
1) Trachea
2) Bronchi
3) Bronchioles
4) Terminal Bronchioles
What are the branches of the respiratory zone?
1) Respiratory bronchioles
2) Alveolar ducts
3) Alveolar sacs
Name four characteristics of conducting zone.
1) Extends from top of trachea to ending of terminal bronchioles
2) Does not contain alveoli and does not participate in gas exchange
3) Bronchioles can constrict in response to irritation via smooth muscle layer
4) Asthma is pathological bronchiole constriction mediated by smooth muscle
What is the total surface area of the 300 million alveoli found in the respiratory zone?
70 m^2
What are alveolar ducts and sac lined by?
Type 1 and Type 2 alveolar (epithelial) cells
Type 2 cells secrete ______.
Surfactant.
What do capillary endothelial cells exchange gases with?
Alveoli across a shared basement membrane.
What function doe the mucus escalator serve?
Keeps lungs free of dust and bacteria.
What are the two main characteristics of the mucus escalator?
1) Secrete mucus
2) Have cilia that continuously beat and move the mucus upward toward the pharynx; mucus is then swallowed
