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Let's talk about the olfactory bulb.

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We can see it on a coronal thin section image.

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There it is, right there.

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A bulbous group of paired gray structures lying just above,

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lying just above the superior nasal concha and nasal cavity.

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Do a little scrolling here.

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As we go back, you can see they spread out a little bit,

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become a little bit thinner as the optic tract.

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We go forward,

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they're a little bit more round

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and bulbous and easy to see.

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Now they are communicating with a group of glands

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that sit in this mucosa right here.

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And these glands, these organs of Schultz,

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or receptors of Schultz are collectively known as

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the olfactory gland. So it's not one single gland.

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I'd like to draw a little bit.

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Let's draw the bulb and the optic tract.

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I'll use my favorite drawing color,

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which is yellow because it's easy to see.

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I'll make it a little bit bigger than it should be.

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And as we come back a little bit, I'll color it over.

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So this is fatter than it would normally be.

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Right there is going to be the optic nerve.

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There's the bulb right there.

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I've got my pen right over it.

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I'll put a little dot on it so you can see it right here.

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When I take it away, you'll be able to see it.

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And I'll put a little dot over the two olfactory bulbs.

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Now, coming into the olfactory tract from the back,

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just for the sake of completion right now is going to be a

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lateral stria. Actually, I'll use a different color,

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something a little easier to see.

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Let's use red. So a lateral stria over here,

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an intermediate stria, a medial stria.

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And then you're also going to have a diagonal band that goes

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over to the amygdala called the diagonal band of Broca.

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And then you're also going to have another bifurcation here

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that goes into the anterior commissure and crosses

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the midline. So in total, there are five of them.

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Let's go back to a sagittal drawing of the olfactory

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bulb and tract. We'll go back to my yellow.

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I'm going to draw right over it.

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It's a very thin stripe under the gyrus rectus.

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Then it has a little bulbous configuration.

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There's your bulb right there.

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And then it comes back.

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And now I'm going to blow it up for you.

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Pardon my drawing skills. And as you know,

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there are a bunch of tracts coming into it from the back.

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Five of them.

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You've seen them in the axial projection.

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And now let's pretend we've got some mucosa underneath.

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A couple of words about the olfactory bulb.

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The olfactory bulb is actually a gray matter mass.

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It's an evagination of the telencephalon, as stated,

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located between the gyrus rectus and the cribriform plate.

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And it contains neurons known as mitral cells.

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So now let's look at what happens.

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Our tracts are coming forward into the bulb.

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And when they get into the bulb,

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we'll have three of them here.

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They become mitral cells.

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They pass right through the mitral cells and.

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Cells blue. So the mitral cells are right here.

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Then the next thing that happens is a synapse.

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So we'll make the synapse something interesting,

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like some type of weird magenta.

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So now you have a synapse right there.

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And then you have continuation with primary sensory axons

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right into the glands of Schultz in the nasal mucosa.

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So we'll draw that in maybe green.

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So it'll perforate the cribriform plate,

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go right into the nasal mucosa,

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and it will pick up these receptors,

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these glands of Schultz.

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And we'll make those kind of a weird

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looking purple so you can see them.

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So that's more or less how things go for the olfactory bulb.

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The dendrites continue in the olfactory tract,

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which terminates in the region of the trigone.

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So you've got dendrites right here.

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You've got axons coming back that would

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I could color them in blue,

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but right at this locus now I'm going to take it away,

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the olfactory trigone.

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This shelf right here is the termination location for those

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axons before they bifurcate into those five separate

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divisions that I described medial, lateral, intermediate,

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diagonal, bandaboka,

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and the one going to the anterior commissure.

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We'll talk about those in a separate vignette.

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That's the anatomy of the olfactory bulb.