GMS6402 final exam | Questions And Answers Latest {2024- 2025} A+ Graded | 100%
Verified
during expiration, does the pleural pressure increase or decrease - increases
what is the pleural pressure at maximal expiration - +30 cm H2O
does air way resistance increase or decrease during expiration - increases
what is equal pressure point and where is it located during expiration - when the pressure in the airway
equals the pressure in the pleural space, near or in segmental bronchi
what is the alveolar pressure during expiration - +40, this helps keep the alveoli from collapsing
why does the trachea not collapse with the increased pressure and resistance - cartilage rings
where does dynamic airway compression occur and what does it lead to - downstream of equal pressure
point (so towards mouth) and residual volume
during breathing, is work done on inspiration or expiration - inspiration
what are some examples of restrictive diseases - pulmonary fibrosis and edema
what are some examples of obstructive diseases - asthma and emphysema
how do we differentiate between restrictive and obstructive diseases - look at the forced vital capacity
(FVC)
what is a normal value for a FVC - 5.0 L
,what is a normal value for a FEV1 (forced expiratory volume in 1 second) - 4.0 L
what is a normal volume for the FEV1/FVC ratio - 80%
what happens to FVC FEV1 and the ratio in restrictive diseases - both reduced, ratio is greater than 80%
this is due to high recoil, never fully inflate but deflate very quickly
what happens to FVC FEV1 and the ratio in obstructive diseases - both reduced, ratio is less than 80%
this is due to low recoil, may inhale same but breathe out slowly
what 4 factors influence the FVC - -strength of chest and abdominal muscles
-airway resistance
-lung size
-elastic properties of lungs
what is a very important muscle for expiration - rectus abdominus
do restrictive and obstructive diseases both have an increase or decrease in VC - decrease
for restrictive: due to decreased TLC
for obstructive: due to increased RV
what are the 4 stages of lung inflation - -stable lung volume
-opening of airways
-linear expansion
-limit of airway inflation
, what does the pleural pressure have to get to before the airways start to open - -8 cm H2O
what is hysteresis - the difference in the inflation and deflation lines of the pressure volume curve
exists bc it takes more pressure to open closed airway than to keep open airway from closing
what is the formula for work - force x distance
delta P = force
delta V = distance
in the pressure volume curve, what does line AEC mean - compliance
in the pressure volume curve, what does ABCDA mean - total work of breathing
pressure volume curve for restrictive diseases - flatter AEC (compliance) line, also means smaller delta
V/delta P
much more work done (ABCDA)
what point in the pressure volume curve is not a physiological point - D
pressure volume curve for obstructive diseases - less work required to inspire
work IS required to expire, goes to left of normal AD line
line AEC is higher, higher compliance
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 oneclass. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $13.48. You're not tied to anything after your purchase.