Midterm 2 Flashcards
What do the alveolar macrophages do?
they ingest debris in alveoli and become trapped in the mucus sheets
What do the type II alveolar cells do?
they secrete surfactant which lowers the surface tension of alveolar fluid to inflate the alveoli and prevent alveolar walls from sticking together and collapsing
What are type II alveolar cells?
they are a kind of stem cell that is able to regenerate more of itself and type I
Where is the respiratory epithelium found?
nasal cavity, nasopharynx, and the large airways
What is the respiratory epithelium?
a pseudostratified epithelium that has a mucus layer that floats on a serious (watery) layer
What are the causes for emphysema?
smoking and other irritants like pollution or dust
What is emphysema?
the breakdown of alveolar walls producing abnormally large air spaces and lowering the surface area for gas exchange ( reduced respiratory efficiency) and reducing the elastic recoil ( due to loss of elastic fibers)
What happens during an asthma attack?
the bronchioles are affected and inflamed and become susceptible to contraction by mediator histamine which causes the contraction of smooth muscle
What is the function of the elastic fibers in the airway wall?
they predominate in smaller airways and the respiratory portion. Their elastic recoil provides force for expiration
What is the function of the smooth muscle in the airway wall?
it predominates in smaller airways and controls the diameter of the airway. The constriction of it reduces airflow
What is the function of cartilage in the airway wall?
it is found in larger airways and helps keep them open
What is the funciton of the respiratory airway?
both to conduct air and respire
What structures are apart of the respiratory airway?
located entirely within the lung and are represented by respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli
What is the function of the conducting airway?
to warm, moisten and conduct air
What structures are included in the conducting airway?
the nose, pharynx, larynx, trachea, bronchi, and bronchioles
What are the 2 types of airways?
conducting and respiratory
What is the function of the alveoli?
to minimize amount of tissues but maximize air space
What is the respiratory bronchioles?
they are the start of the respiratory airway, and they terminate on alveolar ducts
What is the function of the terminal bronchiole?
to move air in and out, it is the last conducting airway
Cartilage ring shape of the trachea?
C-shaped not O-ring shaped
The amount of cartilage in bronchioles and bronchi ?
bronchi- little cartilage
bronchioles- no cartilage but supported by smooth muscle
What is the root (Hilum) of the lung?
the site where blood vessels, lymphatics, nerves, and airways enter and leave lungs
What happens when you swallow?
when passing food any connection between the breathing and GI tract must be cut off so the tongue will push the soft palate up and back closing the nasopharynx. The epiglottis is also closed by bringing the larynx up
What are turbinates? (nasal conchae)
bony shelves covered in a mucous membrane that force air close to the warm wall (narrow channels)