Resp A&P High Yield Flashcards
What makes up the anatomic dead space in the lungs?
Conducting zone
Which can be found further down the conducting zone…goblet cells or pseudostratified ciliated columnar cells? Why is this important?
pseudostratified ciliated columnar cells–> because it help to “beat up” the mucus produced
What comprises the respiratory zone of the resp tree?
resp bronchioles, alveolar ducts, and alveoli
Describe the histology of the lining of the respiratory zone?
Cuboidal cells
What do Type I pneumocytes look like?
Squamous (thin for optimal gas diffusion
What do type II pneumocytes look like?
Cuboidal
What are the 2 functions of Type II pneumocytes?
1- Precursors for type I
2- secretion of surfactant
When do alveoli have a tendancy to collapse (insp or exp)? Why is this?
Collapse in expiration due to decreased radius
What is the most important component of surfactant?
Dipalmitoylposphatidylcholine
When does surfactant synthesis begin? When are the levels high enough?
Begin @ 26 weeks
Mature @ 35 weeks
What cells secrete the proteinaceous component of surfactant?
club/ clara cells
If you were to aspirate while upright where would the aspirate go?
Lower portion of right inferior lobe
If you were to aspirate while supine where would the aspirate go?
Superior portion of the right inferior lobe
What type of fissure is found in BOTH lungs?
Oblique
What level does the IVC go through the diaphragm?
T8
What level does the Esophagus go through the diaphragm?
T10
What level does the vagus go through the diaphragm?
T10
What level does the aorta go through the diaphragm?
T12
What level does the throacic duct go through the diaphragm?
T12
What level does the azygos vein go through the diaphragm?
T12
What nerve (and nerve roots) innervates the diaphragm?
Phrenic nerve–> C3- C5
Where does diaphragm irritation refer to?
Shoulder (C5)
What level does the common carotid bifurcate?
C4
What level does the trachea bifurcate?
T4
What level does the abdominal aorta bifurcate?
L4
“air that can still be breathed in after normal inspiration”
Inspiratory reserve volume
“air that moves into lung with each quiet inspiration”
tidal volume
“air in lung that can still be breathed out after normal expiration”
Expiratory reserve volume
“air in lung after maximal expiration; cannot be measured on spirometry
reserve volume
“IRV + TV”
Inspiratory capacity
“RV + ERV”
FRC
“TV +IRV + ERV”
Vital capacity
“IRV + TV + ERV + RV”
TLC
What balances the inward pull of the lungs at FRC?
Outward pull of the chest wall
What are airway and alveolar pressures at FRC?
Zero!
What are intrapleural pressures ar FRC?
Negative
What conditions are associated with decreased compliance?
Pulmonary fibrosis
Pneumonia
Pulmonary edema
What conditions are associated with increased compliance?
Emphysema
Normal Aging
Which form of Hemoglobin has a low affinity for O2… T or R?
T
What factors favor the T form (deoxygenated) of Hb? Which way does the curve shift?
Shifts to the RIGHT with:
Increased Cl-
Increased H+
Increased CO2
Increased 2,3- BPG
Increased Temp
Hb is a buffer for…
H+ ions
Methemoglobin has an increased affinity for what molecule?
Cyanide
How is methemoglobin treated?
Methylene blue
What is a method for inducing methemoglobinemia?
Nitrates followed by thiosulfate
What is carboxy Hb?
Hb bound to CO in place of O2
Which way does the O2 binding curve shift in CO poisoning?
To the LEFT
Why is myoglobin curve not sigmoidal?
Because there is no coopertive binding due to its monomeric nature
A decreased affinity is indicated by a ____ shift in the curve.
Right shift
Which Hb curve is further to the left…HbF of HbA?
HbF
How is O2 content defined?
(O2 binding capacity X % saturation) - dissolved O2
How much O2 can 1g Hb bind/.
1.34 mL O2
Which is decreased when there is decreased Hb?
O2 content
O2 saturation
Arterial PO2
O2 content decreases
The others stay the same
What occurs in a decreaesd PAo2?
Hypoxic vasoconstriction that shifts blood away from poorly ventilated regions of lung to well ventilated regions of lung to well ventilated regions of lung
What gases are typically perfusion limited?
O2, CO2, N2O
“gas equilibrates early along the length of the capillary”
Perfusion limited
“gas does not equilibrate by the time blood reaches the end of the capillary”
Diffusion limited
What gases are diffusion limited?
O2 in emphysema or fibrosis
CO
What can cause hypoxemia (decreased PaO2) with a normal A-a gradient?
High altitude
Hypoventilation
What can cause hypoxemia (decreased PaO2) with an increased A-a gradient?
V/Q mismatch
Diffusion limitatino
Right-to- left shunt
What is hypoxia?
decreased O2 delivery to tissue
What is V/Q at the apex of the lung?
3
What is the V/Q at the base of the lung?
0.6
Where are ventilation and perfusion BOTH greater…base or apex of the lung?
Base
During exercise what happens to the V/Q ratio at the base of the lungs?
It increases! Approaches 1
How is the majority of CO2 transported in the blood?
As HCO3- (with H+ bound to Hb)
Where can CO2 bind Hb?
N terminus of globin chain
What is the mechanism through which HCO3 leaves RBCs?
Cl-/ HCO3 - antiporter
What happens to 2,3 BPG levels in high altitudes?
They increase…in an effort to derease Oxygen binding affinity–> to allow for oxygen to be unloaded in the tissues
How does the body compensate for the respiratory alkalosis created by hyperventiation in response to altitude?
Increased renal excretion of HCO3
Why does the pH decrease during strenuous exercise?
Due to lactic acidosis–> aids in Oxygen unloading!
