Lecture 24 (Exam IV) Flashcards
(41 cards)
What is emphysema
- A disease where the inside of the lungs are shredded
- There is much less surface area available for gas exchange
- There is an increase in lung compliance which makes the lung stretchier and easier to fill.
- There is a decrease in elastic recoil which makes the lung harder to empty
- TLC and RV are increased
- What happens to the alveoli with COPD/Emphysema patients?
- How does this happen?
- What is the product/result of this?
- They lose alveoli
- This happens due to losing elastic recoil and the alveoli merging together.
- The product of this is less elastic recoil and less surface area availabale for gas exchange.
What causes the loss of elastic recoil over time in emphysema patients?
A digestive enzyme located within the lungs
What do digestive enzymes typically due in our lungs?
- They destroy things like debri, bacteria, and other particles that shouldn’t be in our lungs.
- They also help eliminate fluid build up problems.
What are the digestive enzymes in the lungs called?
Neutraphil elastace (a version of trypsin)
- Is trypsin (neutraphil elastace) always on in the lungs?
- What is its normal level of activity?
- It is always active in the lungs
- Has a very low level of activity when there is no work to be done (like destroying bacteria).
What can trypsin (neutraphil elastace) do in the lungs if its unregulated and has a high level of activity?
It will start destroying and eating up the lung tissues, specifically the springs for elastic recoil on our alveoli.
- What is alpha-1 antitrypsin?
- What is its job in the lungs?
- This is a molecule in the lungs that inhibits trypsin most of the time when it is not needed.
- It is was keeps trypsin activity low and from destroying lung tissue.
Where is alpha-1 antitrypsin produced?
- In the liver
- It then follows the blood stream into the lungs to inhibit trypsin.
What would happen if our alpha-1 antitrypsin didn’t work or we didn’t produce enough of it?
- Trypsin would have a very high activity level in the lungs because it is no longer being inhibited
- The trypsin would eat up all the elastic recoil in our lungs.
- We wouldn’t be able to exhale all the air out of our lungs which gives you a high RV and FRC
- We would have less surface area available for gas exchange.
- It would give you emphysema
What scenarios would cause you to have an alpha-1 antitrypsin defiency, or an issue with the enzyme where it doesn’t work properly? (4)
- Inherited genetic alpha-1 antitrypsin deficiency.
- Smoking - it is a chemical inhibitor of alpha-1antitrypsin, and impairs the activity. This is how long term smokers get emphysema.
- Liver problems - If you don’t have normal liver function (especially from alcholol) then you will lack the alpha-1 antitrypsin since it is produced in the liver.
- Anything that results in inhibiting alpha-1 antitrypsin production in the liver or function in the lungs.
- How many people have an inherited genetic alpha-1 antitrypsin deficiency?
- What does this result in?
- What is the lifespan of these patients?
- 1 in 3,000
- This results in early genetic emphysema
- Death by the age of 30
- What is the treatment for inherited genetic alpha-1 antitrypsin deficiency?
- What is the pitfall of this?
- A lung transplant
- The patient will still have the alpha-1 antitrypsin deficiency since it is made in the liver, a lung transplant just buys them more time so they don’t die at an early age.
Fe++
* Is this iron good or bad?
* What is the name?
* How many charges does it have?
* What is it capabale of?
- Good
- Ferrous iron
- 2 + charges
- capable of temporarily binding and releasing oxygen
Fe+++
* Is this iron good or bad?
* What is the name?
* How many charges does it have?
* What is it capabale of?
- bad
- Ferric iron
- 1 electron has been remvoed which gives it 3 + charges.
- This iron cannot release oxygen because it binds permenantly
What happens to iron if we get a lot of oxidative stress?
Fe++ (ferrous) turns into Fe+++ (ferric)
What are the 2 other names of Fe+++ ferric iron?
- methemoglobin
- Oxidative iron
Can Fe+++ deliver oxygen to the tissues?
no
How much of our circulating hemoglobin is in the ferric form?
1.5%
Explain why a normal arterial blood sample is technically 97.4% instead of 100%.
- 1% of the lowered number comes from the bronchial admixture from the lung perfusion that doesn’t go through gas exchange and gets put directly into the left atrium to be mixed in with the newly oxygenized blood from the lungs.
- The other 1.5% comes from the little bit of oxygen that is bound to ferric iron and cannot be used because the oxygen is bound so tightly and it is in the state of oxidation and cannot be used in the body.
What is methemoglobin reductase?
- An enzyme that does a reduction reaction to change the ferric iron back to ferrous iron.
- It adds an electron which removes the positive charge.
- We go from 3+ to 2+
What kind of reaction happens when we go from ferrous iron to ferric iron?
- It is an oxidation reaction.
- Here we are removing an electron which gives the iron its 3rd positive charge.
- The iron goes from 2+ to 3+.
- we are oxidizing the iron by removing an electron.
How many chains does hemoglobin have on it?
4
What are the adult hemoglobin chains?
- 2 alpha
- 2 beta
