exam 2- respiratory Flashcards
pulmonary space
the whole pulmonary cavity (largest)
pleural space
a “potential” space between the 2 vicera (chest wall and lungs)(middle)
pulmonary interstitial space
a “potential” space between the cap mem and the alveolar mem. (smallest)
what do you not want in the pulm. interstitial space
water/fluid
why did they call it surfactant
surface
active
agent
what is surfactant
substance (lipoprotein) produced by the alveoli
what is the purpose of surfactant
reduces the surface tension and allows the alveoli to stay open for gas exchange
what do the pulmonary capillaries of alveolar and cap membrane form
a network around each alveolus so dense that an almost continuous sheet of blood covers the alveoli
how many blood cells can move through ta pulm capp at a time
one, they must move in a single file line
each RBC stays in cap bed for how long and how many alveoli does it exchange with
1 second
2-3 alveoli exchange
normal ventilation stimulates what in the alveoli
surfactant replacement
what happens to the alveoli when a person hyperventilates
leads to alveolar collapse (atelectasis)
normal alveolar unit
normal ventilation
normal perfusion
dead space unit
(pulmonary emboli)
normal ventilation
NO perfusion
shunt unit
NO ventilation
no perfusion
(tumor or fluid blocking the air from reaching alveoli)
silent unit
NO ventilation
NO perfusion
ventilation
movement of atmospheric air into the alveoli
diffusion
movement of o2 across alveolar walls into pulm caps
perfusion
movement of o2 to and into the cells (tissues)
each rbc has how many HG
300
how many o2 molecules can one HG carry
4
how many o3 molecules can one RBC carry
1,200
what are the 7 steps required to transfer O2 from environmental air into cells
ventilation of lungs
transport of o2 from alveoli into plasma
co2 out
circulation of blood
diffusion of o2 from cap into intersitital fluid
diffusion into cells
diffusion of o2 into mitochondria where it synths ATP
if any of the 7 steps of air to cells is interrupted, what happens
tissue becomes hypoxic
hypoxemia
decreased oxygenated of the arterial blood
hypoxia
decreased o2 levels of the cells
why might hypoxia be localized
a blood clot, where the person doesn’t need to be hypoxemic generalized
what are the four major etiologies of hypoxia
reduced transfer of O2 from alveolar (atmospheric) air to blood (hypoxemia)
decreased HgB concentration
decreased inspired O2
Ichemia
what are etiologies of reduced transfer of 02 from alveolar air to blood
hypoventilation
impaired transport of O2 across alveolar membrane
ventilation perfusion mismatch
hypoventilation:
decreased rate and or depressed depth of respirations
risk for those who have undergone anethesia
what two things can impaire transport of 02 across alveolar membrane causing the diffusion capaity of alveolar membrane to be affected
drug overdose
general anesthesia
chest and abdominal pain (surgery or trauma)
surface area available (fluid)
thickened membrane (pulmonary fibrosis)
intestinal space issues (fluid, infection)
what is ventilation perfusion mismatch
ventilation (air into alveoli) and perfusion (pulmonary cap blood flow) normally match but respiratory disease lead to mismatch
what are the etiologies for decreased HGB concentration
anemia
CO poisoning
what is/causes anemia
blood loss
decreased production of RBC’s
decreased iron intake
what is CO poisoning
Co combines with HGB at same site as O2 and blocks sites for O2
HGB likes CO better than O2
what are the etiologies for decreased inspired O2
breathing high altitude air
breathing air from which o2 has been removed (fire)
what are the etiologies of ischemia
decreased blood flow to tissue
why would blood flow decrease to tissues
vasoconstriction
obstruction in BV
decreased cardiac ouput
what causes local or regional ischemia
vasoconstriction
blocking
(ie atherosclerosis of iliac arteries leading to decreased blood flow to legs)
what causes general systemic ischemia
decreased perfusion of o2 to tissues caused by heart not pumping enough
why does hypovolemic shock lead to ischemia
loss of blood volume = lack of blood= lack of O2 perf
what are the manifestations of hypoxia
decreases SaO2, pO2
increased pCO2
decreased pH (respiratory acidosis)
what are the early signs of hypoxia
confusion
lethargy
increased HR
change in behavior