Final Exam - Odds and Ins Flashcards
(23 cards)
How are alveoli lost and compliance increased in emphysema?
Alvelar tissue is destroyed and can merge
What enzyme in the lungs is digestive and always active?
What does increased activity cause?
- Trypsin, normal activity is low
- Increased activity destroys normal elastic recoil tissue
What inhibits trypsin in the lungs?
⍺1-antitrypsin
What 3 things can cause a ⍺1-antitrypsin deficency?
- Inherited disorders (1:3,000) - leads to death by 30 w/o transplant
- Smoke - chemically inhibts activity, cant be filtered by nose/lungs
- Liver problems - causes decreased production of ⍺1-antitrypsin
Why do people who smoke increase how much they smoke when they drink?
- Drinking increases liver activity which increases nicotine metabolism
- This means they are going through their nicotine levels quickly
What form of iron is normally on Hb?
Fe++ - Ferrous
What does oxidative stress do to the iron on Hb?
Loss of an electron creating Fe+++ - Ferric
This is bad because it cannot release O2
What percent of Hb is in the Ferric state normally?
~1.5%
What enzyme reduces ferric Hb to ferrous Hb?
Methemoglobin Reductase - adds an electron
What are two types of sickle cell anemia and their cause?
Sickle cell trait = 1 defective β gene
Sickle cell disease = 2 defective β genes
What is the diameter of a capillary?
Smaller than size of RBC, meaning RBC change their shape when they move through
What happens to RBC in sickle cell anemia?
The RBC becomes sickled in the capillary after the O2 is offloaded leading to ischemia
These abnormal RBC have to be removed from circulation, leading to anemia
Treatments for sickle cell anemia?
- Decrease activity
- Replace with donor blood
- Hydroxyurea - increases the amount of HbF (β sububits are replaced by Ɣ subunits)
Why is sickle cell trait still in the gene pool?
Causes increased resistance to malaria
What is HbA1C?
Adult Hb with looking at 1C position
The more Hb with sugars attached increases likelihood of DM
What is the normal amount of HbCO (carboxy Hb) in our body?
What would be the level if working in an environment where you are exposed?
- 1 %
- 4 %
How are the chemoreceptors different in emphysema?
When can this be bad?
- Chronically increased pCO2 and H+ leads to a decreased sensitivity to their changes
- The respiratory drive changes to looking at pO2 for primary gauge for ventilation
- A problem when on too much supplemental O2 is that the sensors stop stimulating ventilation - this worsens their acidosis because they are no longer getting blown off
How does increased cardiac ouput affect gas exchange?
- Not all of the alveoli/capillaries are being used at rest
- When CO is increased those capillaries are recruited and increases the SA available for gas exchange
How often do we sigh?
12-15x/hour
Why do we sigh?
How does this play into anesthesia?
- In order to sigh, we have a deeper breathe before hand
- This deeper breathe maintains patency of alveoli and surfactant production
- Anesthesia machines have a “sigh” setting which causes an increased Vt at regular intervals
Why is adding surfactant to a normal ventilator not helpful for lung diseases?
Becasue the alveoli that need the surfactant are closed and only adding surfactant is not helpful
Why do we yawn?
Yawn increases our lung volume before we lay down and decreases our lung volume
What can a traumatic brain injury do to the respiratory control centers of the brain?
Trauma can cause a physical seperation of the PRG from the medulla leading to apneustic breathing
