Sunday, May 12, 2013

Oxygen - hemoglobin dissociation curve mnemonic

Hi everyone!
What is oxygen - haemoglobin dissociation curve or oxygen binding curve?
The oxygen - haemoglobin dissociation curve plots the proportion of haemoglobin in its saturated form on the vertical axis (fractional saturation of hemoglobin) against the prevailing oxygen tension on the horizontal axis.

What does it tell?
It tells you the affinity of hemoglobin for oxygen.

How does it do that?
It's simple!
If the curve shifts towards the right, hemoglobin has decreased affinity for oxygen.
If the curve shifts towards the left, hemoglobin has increased affinity for oxygen.

How do I remember the shift in curves?
Remember: Left shifted curve doesn't want to leave oxygen.

Friday, May 3, 2013

Obstructive and restrictive lung diseases

Happy friday everyone!
We’ll learn about obstructive and restrictive lung diseases today.
This is just a short summary for a quick review :)

Obstructive lung diseases - Characterized by airway obstruction.
You have an obstruction in air flow resulting in air trapping in the lungs.
Increased compliance: Due to the loss of alveolar and elastic tissue.
You have a problem getting air out of your lungs.
Mnemonic: Obstructive Out

They breathe like “poof poooooof”
In and oooooout
They take infinity to get it all out =P
So, FEV1 / FVC is decreased.

TLC and RV increased - Flow volume loop shifts towards left.

Examples: Any pathology that decreases the ability to develop a positive intrapleural pressure.
(Airways close prematurely at high lung volumes!)
Chronic bronchitis

Restrictive lung diseases - Characterized by restriction of lung expansion.
You have a problem getting air into your lungs.
Reduced compliance: Lungs become fibrotic, lose their distensibility and become stiffer.
Mnemonic: Restrictive Reduced compliance

They breathe like “poof pof”
In and out
They get everything out in one second =P
So, FEV1 / FVC is increased.

TLC and RV decreased - Flow volume loop shifts towards the right.

Examples: Any pathology that decreases the ability to develop a negative intrapleural pressure.
Pulmonary fibrosis

That's all!

I know you must've found the "poof" sounds pretty weird because that isn't the way you breathe
But they are a funny and they help me remember so I put it up anyway ^___^"
Just like "lup dubb" are official sounds for heart beats.. Which sounds would you assign to inspiration and expiration?


Updated: Diagram on 28th Nov, 2013.