Respiratory system Flashcards
What are the 7 functions of the respiratory system?
- provide oxygen
- eliminate C02
- Regulate blood pH
- Facilitate speech
- Provides microbial defense by means of epithelial secretions
- Activate and inactivate chemical messenger in blood
- Defend against blood clots (dissolve them in the narrow vessels of the lungs.
What are the 3 components of the respiratory system?
- lungs
- airways
- Mechanical aids (skeletal muslces)
What are the 3 regions of the Airways?
- Upper airway = structures outside of thoracic cavity (mouth/nose, pharynx, larynx, but not gas exchange occurs)
- Conducting zone = in thoracic cavity, but no gas exchange occurs here. (Trachea, primary bronchi, secondary bronchi, bronchioles and terminal bronchioles)
- Respiratory zone = structures where gas exchange takes place. (respiratory bronchioles, alveolar ducts and alveolar sacs)
What are the functions of the conducting zone?
- branching maintains airflow and lessens resistance to airflow
- Air is moistened and warmed
- Protects against microbes via goblet cells secretion and cilia that move mucus up towards pharynx where it can be swallowed.
________ is a disease that impairs the normal function of the conducting zone.
Cystic fibrosis = mutation in genetic code for Cl- channels reduces the amount of Na+ and Cl- secreted across the epithelium not the mucus = less water in mucus = mucus is thick and dry. *Infectious agents get trapped, but not expelled.
What are the functions of the respiratory zone?
- Bronchiolar smooth muscle regulate airflow.
- Alveoli well suited for optimizing gas exchange
- Microbial defense is provided by pulmonary macrophages
Describe the 3 cell types of the Alveoli…
Type 1 = epithelial; gas exchange surface
Type 2 = secret surfactant
Macrophages = immune cells
Alveolar sacs are around ___ in diameter.
0.5um
Distance between alveolar sacs is about ______.
0.2um
T or F, Respiratory gases are small, non-polar molecules that diffuse down a concentration gradient and diffuse easily through plasma membranes, yet less easily through body fluids.
True!
T or F, O2 and CO2 have the same diffusion rates.
False,they have different diffusion rates due to different solubilities. (Co2= 77 and O2 = 2.2)
What are the layers of the respiratory surface that gases must cross?
Air in alveolus –> across apical membrane of type 1 cell – through cytoplasm –> across the basal membrane of type 1 cell –> across basal lamina and underlying connective tissue –> across basal membrane of endothelial cell —-> through cytoplasm –> across apical membrane of endothelial cell —> into plasma!
Each lung is surrounded by a ______.
Pleural Sac
What are the 2 layers of the Pleural sac?
Parietal (outer) = pleura adheres to the underside of the thoracic wall and the top of the diaphragm.
Visceral (inner) pleura covers the outer surface of the lung.
*space between layers = intrapleural space filled with fluid that lubricates surfaces.
Is the Intrapleural space subject to pressure changes when thoracic cage expands or contracts?
Yes!
