Histology of Mammal Lung

Histology Continued.  Histology is the microscopic study of human tissue.  We are going to be looking at and discussing different tissue types and layers on a microscopic level.  Even if you don't understand it, I think you will at least find some of the pictures I have taken interesting.

Today's Medical Topic:  Histology of Mammal Lung

What Are We Looking For:  I feel like I shouldn't have to explain what a lung is.  But let's first discuss where exactly this piece of tissue is from in the lung.  My buest gess is that is is a transverse section that includes a small branch of trachea.

So obviously the slide cannot hold an entire transverse section of the lung but definitely part of it.

The Tissue Sample:  So this is mammal lung.  What can we expect to see?  For one we can expect some sort of a piece of trachea or a trachea branch and all the associated tissues with that.  We are going to see part of some alveoli air sacs.  And we are probably going to see some sort of connective tissue.

40x Magnification

The squiggly stuff is alveoli.  Alveoli is composed of simple squamous epithelium.  Ideal for fast filtering but only one cell layer thick.  It is extremely distinctive.  No other tissue type looks quite like it.

The next thing down labeled "This thing" looks like some sort of tracheal branch.  We are going to look at that close up and discuss it in detail.  The next part down I sincerely have no idea what that is supposed to be. I think it is just some degraded tissue because the slide is old.  At any rate we will ignore it for the sake of simplicity.

250x Magnification

So here is a close up of the tracheal branch called a bronchiole.  You can see it composed of more than one distinctive tissue types.  You can see some smooth muscle there.

The darker pink/purple "chunks" that you see are the inner lining of the bronchiole.  This should be either cuboidal or columnar epithelia depending on the size of the bronchiloe.  In this case it appears to be ciliated columnar epithelial tissue.  The ciliated part is for moving dust and debris particles out of the lung.  Lets get closer.

400x Magnification

Here you can clearly distinguish the cilia and also the darker pink line that is the basement membrane of the columnar epithelial layer.

The white space in the middle is just that.  Empty space.  That is the passageway in which air moves when you inhale and exhale.  There are some other tissues scattered about that are difficult to identify with whatever stain was used to dye this slide.

We can assume there is probably some sort of connective tissue in there and also some other passageways and structures which are beyond the scope of my knowledge.  But there is definitively those three distinct tissue types as mentioned above with all of their inherent structures.

Well, this post took way too long.  Next we will look at something simpler.

Send questions or comments to dudaday@gmail.com

Disclaimer:  I am not a health care provider, any information presented in this blog should not be considered advice it is mearly an outlet to slake my curiosity.  You should always consult your primary medical provider for any concerns or illness.  Unlike Tylenol, I am not approved by the FDA or American Medical Association to treat or provide relief for any ailment.