Lecture 1 9/24/24 Flashcards
What is the main function of the respiratory system?
movement of air to lower respiratory tract for gas exchange
Which structures comprise the upper airway?
-nasal passages
-sinuses
-nasopharynx
-larynx
-trachea
-bronchi
What is the function of the upper airway?
air conduction
Which structures are considered tangential to the resp system?
-eustachian tube/guttural pouch
-middle ear
-inner ear
What are the functions of the lungs?
-gas exchange
-air conduction
What type of epithelium is seen in the upper airway?
pseudostratified columnar epithelium with goblet cells
What are Pores of Kohn?
holes between and connecting alveoli
What is the importance of Pores of Kohn?
-present in dogs and cats, allowing for diffuse pneumonia pattern
-absent in cattle, resulting in mosaic pneumonia pattern
What are the characteristics of type 1 pneumocytes?
-very thin
-allow for gas diffusion across alveoli
What are the characteristics of type 2 pneumocytes?
-thicker
-not as good at gas exchange
-produce pulmonary surfactant
-proliferate to repair if type 1 pneumocytes are damaged
What are the components of the blood-air barrier?
-fused basement membrane
-endothelial cells
-type 1 pneumocytes
What are the characteristics of Clara cells?
-make club cell secretory protein
-CCSP produced is anti-inflammatory
-important for metabolism
What are the characteristics of aerogenous entry?
-particle size is important
-heavier/bigger particles deposit first
-smaller particles are more widely deposited
-breathed in
What are the characteristics of hematogenous entry?
-via blood
-multifocal, random, and widespread
-can be diffuse
What are the main mechanisms of clearance for the resp tract?
-coughing/sneezing
-mucociliary clearance
-phagocytosis
How does anatomy of the resp. tract contribute to clearance?
turbulence, stenosis, and inertia force substances against the mucosa
What can lead to the inhibition of mucociliary clearance?
-certain infections/mycoplasma
-dehydration
-smoking
What are the characteristics of alveolar macrophages?
-primary immune cell in healthy lungs
-can be inhibited or evaded
-can cause damage
What is the main characteristic of pulmonary intravascular macrophages?
important for eliminating bacteremia and endotoxins
Which cell other than macrophages is involved in phagocytosis clearance in the resp tract?
lymphocytes in the BALT
Why is the bronchoalveolar junction the most vulnerable part of the resp tract?
it is a transition zone that lacks innate portions and alveolar macrophages
What are the potential sources of injury to the resp tract?
-oxidant gases
-toxic metabolites
-free radicals secondary to inflammation
What are antioxidants?
product of the alveolar/bronchiole epithelial cells and pulmonary interstitium that defends against oxidant and free radical damage
What are the potential causes of impaired defense mechanisms within the resp tract?
-viral infection
-toxic gases
-immunodeficiencies
-ciliary dyskinesia
What is hemoptysis?
coughing blood
What are the types of exudates?
-serous
-catarrhal
-fibrinous
-purulent
-mucopurulent
-fibrinosuppurative
-granulomatous
What are the potential etiologies of exudates?
-allergic
-bacterial
-viral
-mycotic
-parasitic
What must be included in an inflammatory morphologic diagnosis of the resp tract?
-severity
-time course
-distribution
-inflammatory modifier
-location
