Lower Respiratory System Flashcards
Where does the trachea end?
The carina
At what thoracic level is the carina?
Roughly the 5th thoracic vertebrae.
Why is it more likely that you will enter the right lung accidentally?
The right lung branches off at about 25 degree angle, and it is wider and more vertical than the left.
What are the major bronchial divisions of both lungs?
There is left upper and lower, and right upper, middle, and lower.
What is peribronchial connective tissue?
A sheath that surrounds the subsegmental bronchi containing pulmonary vessels, bronchial arteries, lymphatic vessels, nerves, and of course the bronchus itself.
Where does the bronchial tree stop having cartilage on it?
At the subsegmental bronchi
At which generation of the bronchial tree does the airway change from conductive to respiratory?
From generation 17 (respiratory bronchioles) to the last generation, 25 (the alveolar sacs).
What are the three layers of airway tissues?
Cartilage (outermost), lamina propria, and epithelium (innermost).
What kind of tissue makes up the epithelium of the airway?
Pseudostratified ciliated columnar epithelium from trachea to respiratory bronchioles.
What is the purpose of the basal membrane of the airway?
It separates the epithelial cells from the lamina propria and is made of basal cells
Where in the airway do we find mast cells and what are they?
They are found in the lamina propria and are immune cells often responsible for anaphylaxis and asthma inflammation.
What controls the tone of the smooth muscle of the airway and how?
The autonomic nervous system controls the smooth muscle. The sympathetic dilates and the parasympathetic contracts.
What is the functional unit of the lungs?
The alveoli
Where does the flow of inspired gas stop?
The terminal bronchioles
What is Brownian movement?
The natural molecular flow of gas that is the dominant mechanism of gas movement in the terminal bronchioles (alveoli).
What kind of cells are found in the alveoli?
Type I (squamous pneumocytes) which are responsible for gas exchange and Type II (granular pneumocytes) which are responsible for the production of surfactant
What does surfactant do?
It reduces the surface tension of the fluid lining the alveoli to facilitate the movement of gas through the membrane.
What are type III pneumocytes?
They are macrophages that remove bacteria and other wastes from the primary lobule
Where do type III pneumocytes originate?
They originate from stem cells in the bone marrow.
What is tight space and loose space in the lungs?
Tight space is space between alveolar epithelium and endothelium of pulmonary capillaries and loose space surrounds the acini (around alveoli and capillaries).
What are the Channels of Martin?
Channels between bronchioles for communication.
What are Canals of Lambert?
Small channels between alveoli and terminal bronchioles.
What are pores of Kohn?
Channels between alveoli for communication that are formed because of disease, age, or macrophages (infection).
What are Clara cells?
A type of cell found in the primary lobule that protect the bronchiolar epithelium and may contain enzymes that detoxify inhaled substances.
