Exam 6: Respiratory Introduction Flashcards
What are the cell types found in the alveolus?
Epithelial type I and II Macrophages Polymorphonuclear cells Mast cells Clara cells Endothelial cells
What is the function of epithelial type I cells?
Occupies the vast majority of alveolar surface area and lines the alveolus
Responsible for gas exchange
What is the function of epithelial type II cells?
Responsible for surfactant production and for repair of epithelial damage
What is the function of macrophages?
Phagocytize
What is a PMN cell?
An abundant white blood cell found in the peripheral blood of many mammals
Describe mast cells
Immune function
WBC that contains histamines and heparin
Describe clara cells
Found at the level of the bronchiole and have a secretory function
May also play a role in epithelial regeneration after injury
Where are endothelial cells found?
Inner lining of alveolus
What is the symbol for partial pressure of oxygen in mixed venous blood?
PvO2 with a line over the v
What is the symbol for carbon dioxide production?
VCO2
What is the symbol for expired minute ventilation?
V_E with a dot over the V
What is the symbol for tidal volume?
V_T
What are the 3 functions of the nasal cavity?
Warms, filters, and humidifies inspired air
What is the contribution to resistance during normal breathing for the nasal cavity?
50%
What is the contribution to resistance during normal breathing for the trachea?
20%
Describe the mucosa of the trachea
Pseudostratified ciliated columnar epithelium
Goblet/apocrine cells that secrete a portion of the fluid that lines the airway
Describe the tracheal lumen
Lined by ciliary cells that contribute to the mucociliary apparatus
What is the mucociliary apparatus?
Where cilia sweep mucus and foreign particles up an out of the trachea
What is found in the submucosa of the trachea?
Basal cells
Compare and contrast the structure of the trachea to the bronchioles
Trachea has cartilaginous support (cartilaginous rings), but the bronchioles do not
The epithelium in the trachea is pseudostratified ciliated columnar and the bronchioles have cuboidal ciliated epithelium
Gas exchange does not occur in either area
The bronchioles are supported by surrounding parenchyma
There is not submucosal glandular tissue in the bronchioles
There are clara cells ad muscular walls in the bronchioles
What is the major muscle responsible for quiet inspiration?
Diahphragm
What are the accessory muscles for quiet inspiration?
Sternomastoids and scalene
The cricoarytenoideus dorsalis and dilator nasoapicalis are 2 of the muscles of inspiration
How do you calculate dead space? What are the variables?
VD/VT = PaCO2 – PECO2 / PaCO2 PaCO2 = concentration of alveolar carbon dioxide PECO2 = partial pressure of expired carbon dioxide VD = dead space VT = tidal volume
How do you calculate alveolar gas tension? What are the variables?
PAO2 = PIO2 – (PaCO2/R)
R = between 0.8 (carnivore) and 1 (herbivore)
PIO2 = (atmospheric pressure – water pressure) (FO2)
PaCO2 is about a 1:1 ratio with PACO2 at the level of the alveoli
What are tests that can be used to assess pulmonary function?
Blood gas analysis
Capnography
Pulse oximetry
What are tests used to asses the respiratory system but do not test pulmonary function?
Radiography
Bronchoscopy
Cytology/biopsy
Thracoscopy/thoracotomy
What is the expected partial pressure of oxygen in systemic arterial blood?
85-100 mmHg
What is the expected partial pressure of oxygen in blood form the pulmonary artery?
40 mmHg
What is the expected partial pressure of oxygen in the alveolus?
104 mmHg
Calculate the PO2 of the moist inspired gas of a dog standing on the summit of Mount Everest (PB=247)
aPO2= (PB-PH2O) x FiO2
= (247-47) x .21
= 42mmHg
