After looking at all these sections and slides and close-ups of the various types of brains, what have we learned? What kinds of trends have we observed? What are we still curious about?

When you saw the sagittal slices of all the brains, what did you notice? Comparing across the sections you probably noticed that there were some general differences between the brains (involving size, shapes of structures, etc). For example, it may seem easier to differentiate structures in the human brain as opposed to the rat brain. It has been found that as one ascends a phylogenetic sequence, there is clearer definition and demarcation of structures, almost as if the brain is better organized. Yet, the closer we got, especially when we made forebrain and hindbrain slices, the more you may have realized that the brains and their structures look quite similar. In other words, yes, there are differences between animals' brains but also deep and fundamental similarities. Here are some pictures to remind you:

[insert pic of frog forebrain]

Now we are looking at a cross-section of the forebrain of a frog.

Now we are looking at a cross-section of the hindbrain of a rat.

Can you tell what structure this is? Do you see the convoluted material that is dark purple? That is the cerebellum. What other structures do you see? What is beneath the cerebellum? Although it is difficult to tell exactly what level we are seeing, structures of the brainstem may be apparent. Do you remember what structures constitute the brainstem? It includes the pons, medulla oblongata, and spinal cord.

Where shall we go from here? Click on your browser's "back" button to return to the midsagittal view of the rat brain, or click on one of the buttons below to learn about these structures, to slice other brains, or to move on towards magnification.

Now we are looking at a cross-section of the forebrain of a rat.

As with the human, monkey, and cat forebrains, this image is a good illustration of the cerebral cortex at the frontal lobe of the brain. The dark purple that looks like an outline is gray matter. The light purple inside the dark purple is white matter. You can also see the body of the corpus callosum, which is the structure connecting the two hemispheres of the brain. The white elliptical openings within the brain are ventricles, which are fluid-filled cavities that serve to cushion and protect the brain. You can also see midbrain structures in this image. What else do you notice about this image?

Now we are looking at a cross-section of the hindbrain of a cat.

Can you tell what structure this is? Do you see the convoluted material that is dark purple? That is the cerebellum. What other structures do you see? What is beneath the cerebellum? Although it is difficult to tell exactly what level we are seeing, the pons, medulla oblongata, and spinal cord may be apparent.

Where shall we go from here? Click on your browser's "back" button to return to the midsagittal view of the cat brain, or click on one of the buttons below to learn about these structures, to slice other brains, or to move on towards magnification.