Sample Exam Flashcards
If the rib cage is totally immobile, how is inspiration possible?
by diaphragmatic breathing
During expiration, which statement is true?
alveolar P > atmospheric P > pleural P
What is best associated with transpulmonary pressure?
measure of recoil tendency of the lung
What muscle is active during forced expiration?
rectus abdominis–> only extratory muscle, pulls rib cage down
If the visceral pleural erodes andallows a region of the alvelar space to communicate with the pleural space, what would hapeen to the functional residual capacity?
decreased
Which of the following statements best describes hysteresis at the onset of inspiration?
lung volume changes at aslower rate then the pleural P changes (filling up the lung with saline would diminish these forces)
Which is a function of surfactant?
helps stabilize alveolar size, reduces surface tension, offsets collapse pressure as radius decrease
What effect will histamine binding to H1 receptors have on the airway smooth muscle?
constrict
Using helium dilution method, the following data was obtained: [He]initial= 5ml/L [He]final= 4ml/L initial spirometer volume= 10L TV= 500mL IRV= 3.0 L ERV= 1.5L An adequate number of breaths were completed, and data was collected at the end of normal expiration. What is the total lung capacity?
FRC = (hei/ hef - 1 ) Vi
(4/5 - 1)10
(1.25-1)10
.25(10)= 2.5
- 5 + inspiratory capacity
- 5 + tital volume + IRV
- 5 + .5 + 3.0 = 6L
6.0L
Most of recoil tendency of the lung is due to what?
surface tension forces
What is a pathophysiologic consequence of hyperventilation?
decreased coronary blood flow
decreased stroke volume
repolarization of the heart impaired
skeletal muscle spasm
What is the major effect of sympathetic stimulation on airway smooth muscle?
dilate, most of the effect is indirect via blood borne
Why is the left ventricular output slightly higher than the right ventricular output?
some bronchial artery blood drains into the pulmonary veins
Which volumes or capacities cannot be determined with basic spirometry?
residual volume, functional residual volume
total lung capacity
What local effect will Prostaglandin E series have on airway smooth muscle?
dilation
Which of the following has the greatest effect on constriction of pre-capillary resistance vessels in the lung?
low alveolar oxygen
Without surfactant, as alveolar radius increases, what happens to the collapse tendency of the lung?
decreases
Rank the solubility of the different gases from greatest to least in aqueous fluid?
CO2 > O2 > N2
During exercise in an upright position, flow throughout the lung is equal. True or false?
False
Which of the following conditions would significantly increase total pulmonic blood volume?
mitral valve stenosis
Compared to atmospheric air, alveolar air has a higher concentration of which of the following?
CO2, water vapor
What effect does stimulation of the SNS have on sensitivity of peripheral chemoreceptors to hypoxia?
increases
Which of the following statements about carbon monoxide is true?
Pco of .6mmHg can be lethal
a partial pressure Pco=.4 can significantly decrease O2 transport
has a much greater affinity for hemoglobin compared to oxygen
the body produces very small quantities with physiologic effects
If the ventilation/perfusion ratio increases above normal, which of the following conditions is true?
increase the amount of physiologic dead space