UNMC Patho Exam 2
Oxygenation - ANS-The body's ability to deliver oxygen to all cells via the processes of
ventilation, diffusion, and perfusion
Diffusion - ANS-movement of oxygen across alveolar walls into pulmonary capillaries
Ventilation - ANS-movement of atmospheric air into the alveoli
Perfusion - ANS-movement of oxygen to and into the cells
How does air come into the lungs? - ANS-Create more negative pressure in the pleural
space (cavity) so it is less than atmospheric pressure.
Pleural space is ____ - ANS-A potential space between chest wall and lungs
Pulmonary interstitial space - ANS-A potential space between capillary membrane and
alveolar membrane
If the potential space gets bigger, this means?? - ANS-Something bad (traumatic) has
happened or something is not right
Pulmonary capillaries of alveolar capillary membranes - ANS-Form a network around
each alveolus so dense that an almost continuous sheet of blood covers the alveoli
Describe blood flow through pulmonary capillaries - ANS-Interior diameter of each
capillary is just large enough to allow red blood cells to squeeze by in single file so their
cell membranes touch the capillary walls. Thus, Co2 and O2 need not pass through
plasma when diffusing in and out of alveoli. Each RBC stays in the pulmonary - capillary
bed about 1 second and exchange gases with 2-3 alveoli during this time.
Surfactant - ANS-Lowers the surface tension of alveolar walls, increases lung
compliance (elasticity), and eases the work of breathing. Must be replenished
continuously. Normal ventilation stimulates its replacement. Hypoventilation leads to
alveolar collapse.
Premature babies usually do not have enough ___ - ANS-surfactant
Alveoli and pulmonary capillary walls are how thick - ANS-one cell thick
, Dead space unit - ANS-Normal ventilation but no perfusion (decreased perfusion). Can
get air into your alveoli but there is a blocked exchange of getting to cells. Ex:
Emphysema, blood clot in pulmonary artery like pulmonary emboli
Shunt unit - ANS-Normal blood flow but something is blocking ventilation into the lungs
like fluid, tumor, infection
Silent unit - ANS-Neither ventilation or perfusion, usually a combination of a certain
disorder
How many oxygen molecules can one blood cell carry? - ANS-1200 O2 molecules
Steps required to transfer O2 from environment to cells - ANS-1. Ventilation of lungs
brings oxygen to alveolar capillary membrane
2. Transport of oxygen from alveoli into plasma and RBC's onto hemoglobin molecule
(moves across alveolar wall in the pulmonary interstitial space)
3. Reversible chemical combination of O2 and CO2 with Hgb. O2 combine with Hgb to
other parts of the body
4. Circulation of blood from the pulmonary venous capillaries to systemic capillaries
5. Diffusion of O2 from capillary blood into interstitial fluid
6. Diffusion into cells
7. Diffusion of O2 into mitochondria where (in combination with glucose) it helps to
synthesize ATP
What happens if oxygenation steps are interrupted? - ANS-Tissue becomes hypoxic
Hypoxemia - ANS-decreased oxygenation or arterial blood
Hypoxia - ANS-decreased oxygenation of the cells
Etiologies of Hypoxia - ANS-1. Reduced transfer of O2 from alveolar (atmospheric) air
into blood (hypoxemia). Can be caused by hypoventilation, ventilation perfusion
mismatch impaired transport of O2 across the alveolar membrane - which is affected by
surface area available, thickness of the membrane, or interstitial space problems
(something filling up interstitial space)
2. Decreased Hgb concentration. Caused by anemia (blood loss which lead to not
enough blood cells), or CO poisoning because CO binds with Hgb at same site as O2
(Hgb has an affinity for CO2 greater than O2)
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller modockochieng06. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $7.99. You're not tied to anything after your purchase.