And these are called alveoli.

Let me draw these air sacs.

So you have these air sacs like this.

So you have these vesicles.

literally snared the vesicles to this membrane.

Let me draw one right here.

The alveoli use pressure to move oxygen and nutrients into the blood.

And they move material around, depending on what they do.

They'll then be packaged in a little transport vesicle and moved to the Golgi apparatus.

I'm going to tell you in a second how it gets squeezed.

It is implicated as responsible for the heat resistance of the endospore.

So you have these vesicles so these are just you can kind of view them as containers.

Other things will be coming in, but the O2 is what gets absorbed in the alveoli.

In the last video on the lungs or the gas exchange in our bodies or on the pulmonary system, we left off with the alveolar sacs.

These cells cause disruption of the normal air spaces (alveoli) where oxygen is extracted from the atmosphere.

So going away from the heart to the lungs, to the alveoli, these are the pulmonary arteries.

So if I were to zoom in on one of these alveoli and just to give you an idea, these are super duper duper small.

But anyway, we have our little alveoli right there and then we have the capillaries.

They run right past the alveoli and then they become oxygenated and now we're going back to the heart.

So these little vesicles, they're docked to the presynpatic membrane or to this axon terminal membrane right there.

So what's going to happen is that the air is flowing through the bronchioles and circulating around the alveoli, filling the alveoli and as they fill the alveoli, the little molecules of oxygen are allowed to cross the membrane of the alveoli and essentially be absorbed into the blood.

And then of course we have our bronchiole that feeds into this, and then that might have branched off from another one that feeds into another set of alveolar sacs, but I don't want to get too focused on that.

And what we learned in the last few videos is that we have our little alveoli and our lungs.

But the oxygen will come through our larynx, into our trachea, through the bronchi, eventually in bronchioles, ending up in alveoli and being able to be absorbed into what where the arteries, but then we're going to go back and then essentially oxygenate the blood.

So it's a very small distance and you have on the presynaptic neuron near the terminal end, you have these vesicles.

In the gas phase, it can be used to image empty space such as cavities in a porous sample or alveoli in lungs.

And then when we breathe out, we're going to have carbon dioxide that was in our blood, but then it gets absorbed into the alveoli and they get squeezed out.

Then it goes to the heart, rubs up against some alveoli and then gets oxygenated and then it comes right back.

And just to have a sense of how many alveoli we had I told you that they're very small we actually have 300 million in each lung.

It enters our body through the nose and mouth, moves down into the pharynx, trachea and bronchial tubes, and ultimately reaches the alveoli air sacs in the lungs.

Once in the lungs, bacteria may invade the spaces between cells and between alveoli, where the macrophages and neutrophils (defensive white blood cells) attempt to inactivate the bacteria.

And we said in the last video that you have these capillaries, these pulmonary capillaries that are running all along the side of these alveoli.

It's in the loop with the lungs so it's a pulmonary vein and it rubbed up against the alveoli and got the oxygen diffused into it so it is oxygenated.

And then they pick up the oxygen from inside the alveoli or the oxygen diffuses across the membrane of the alveoli, into these capillaries, into these super small tubes.

Macrovesicular is the more common form of fatty degeneration, and may be caused by oversupply of lipids due to obesity, obstructive sleep apnea (OSA), insulin resistance, or alcoholism.

It makes these vesicles dump their contents in the synaptic cleft and then that will make other sodium gates open up and then that will stimulate this neuron, but if it makes potassium gates open up, then it will inhibit it and that's how, frankly, these synapses work.

The infection of herbivores (and occasionally humans) by the inhalational route normally proceeds as follows Once the spores are inhaled, they are transported through the air passages into the tiny air sacs (alveoli) in the lungs.

Breathing 100 oxygen also eventually leads to collapse of the alveoli (atelectasis), while at the same partial pressure of oxygen the presence of significant partial pressures of inert gases, typically nitrogen, will prevent this effect.