Visualizing the Human Brain (YouTube Video Transcript)

(00:00:00) Your YouTube transcript will appear here (00:00:00) he knows a lot about the science star (00:00:02) professor (00:00:03) dave explains (00:00:07) earlier in this series we spent several (00:00:09) tutorials going over the nervous system (00:00:12) the starting place for that (00:00:13) investigation was the central nervous (00:00:15) system (00:00:16) and in particular the brain we often (00:00:19) describe the brain as the most (00:00:21) complex object in the known universe (00:00:24) consisting of hundreds of billions of (00:00:26) cells (00:00:27) linked by trillions of connections (00:00:29) producing (00:00:30) our own consciousness through mechanisms (00:00:32) that are not yet fully understood (00:00:34) when we first learned about the brain we (00:00:36) were interested in outlining its (00:00:38) overall structure naming each region (00:00:41) and describing their functions but when (00:00:44) concerning oneself with so many (00:00:45) definitions and details (00:00:47) it can be difficult to visualize the (00:00:49) overall three-dimensional layout of such (00:00:51) a complex (00:00:52) object for this reason just as we took (00:00:56) a realistic journey through the heart in (00:00:58) the previous tutorial (00:01:00) let's now get a closer look at some of (00:01:02) the areas of the brain (00:01:04) from a more lifelike perspective as this (00:01:06) will help us concretize what we learned (00:01:09) earlier in the series and solidify our (00:01:11) conception (00:01:12) of brain structure and function (00:01:15) let's start out on the smaller scale and (00:01:17) take a look at some neurons (00:01:19) we spent a whole tutorial looking at the (00:01:22) action potential (00:01:23) and synaptic transmission over in the (00:01:26) biopsychology series (00:01:27) so we should have a sense of how (00:01:29) neuronal cells communicate with one (00:01:31) another (00:01:32) now we can observe the process in action (00:01:36) of course we know that in addition to (00:01:38) the neurons themselves (00:01:39) nervous tissue contains many different (00:01:42) types of glial cells (00:01:43) such as the oligodendrocytes we can see (00:01:47) here (00:01:47) providing support and insulation to the (00:01:50) axons (00:01:51) via a myelin sheath this speeds up the (00:01:55) rate of transmission (00:01:56) through the axon (00:02:01) these myelinated axons also called (00:02:04) tracts are what make up the white matter (00:02:07) of the brain (00:02:08) the white matter allows the different (00:02:10) regions of the brain to communicate with (00:02:12) one another efficiently (00:02:14) and is thereby responsible for a wide (00:02:16) variety of brain (00:02:17) function being heavily involved in (00:02:19) learning and (00:02:20) memory this should offer a more complete (00:02:24) picture of what is being visualized (00:02:26) when we examine a cross-section of the (00:02:28) brain (00:02:29) this sort of image should be (00:02:30) recognizable from any textbook (00:02:33) but with this three-dimensional (00:02:34) representation the distribution of white (00:02:37) matter (00:02:37) should make a bit more sense however (00:02:41) when viewing the brain in this fashion (00:02:43) the innermost (00:02:44) structures of the brain can become (00:02:46) unclear let's get a closer look at those (00:02:49) as well (00:02:50) starting with the areas that are most (00:02:52) crucial to memory (00:02:53) we can head to the bottom of the brain (00:02:55) to find the cerebellum (00:02:57) then heading inside we see the (00:02:59) hippocampus glowing in green (00:03:02) the center of memory and emotion and the (00:03:04) thalamus (00:03:05) glowing in purple relaying sensory and (00:03:08) motor signals (00:03:09) then there is the amygdala in yellow (00:03:12) also heavily involved in the experience (00:03:14) of emotions (00:03:16) and then zooming back out to the frontal (00:03:18) lobe which is concerned with behavior (00:03:21) and learning (00:03:21) among other things we can visualize all (00:03:25) the lobes while we're at it (00:03:26) with the frontal lobe in dark blue the (00:03:29) parietal lobe in green (00:03:31) the occipital lobe in light purple and (00:03:34) the temporal lobe (00:03:36) in light blue (00:03:41) now let's head back inside to get (00:03:43) another look at the innermost (00:03:45) structures apart from the cerebellum we (00:03:47) can now clearly see the entire brain (00:03:50) stem leading up to the limbic system (00:03:53) that collection of structures (00:03:55) surrounding the thalamus (00:03:57) if we strip away these structures we can (00:03:59) get a closer look at the region in (00:04:01) bright blue (00:04:02) this is the choroid plexus along with (00:04:05) the rest of the ventricular system (00:04:08) which is continuous with the central (00:04:10) canal of the spinal cord (00:04:12) via the fourth ventricle the larger (00:04:14) structure towards the bottom (00:04:16) the choroid plexus produces (00:04:19) cerebrospinal fluid (00:04:21) the fluid found in the tissue that (00:04:23) surrounds the brain and spinal cord (00:04:26) occupying the subarachnoid space (00:04:29) between the arachnoid mater and pia (00:04:32) mater (00:04:33) protecting the brain from injury of (00:04:36) course this is not the only fluid in (00:04:38) this region (00:04:39) all of these structures are comprised of (00:04:41) cells and thus (00:04:42) need to be serviced by the bloodstream (00:04:45) so here are all the major blood vessels (00:04:47) that are involved in brain circulation (00:04:51) with these structures and the overall (00:04:53) layout better (00:04:54) understood we can view a sagittal slice (00:04:57) of the brain with more clarity as well (00:05:00) here we see the brain cut vertically (00:05:02) down the middle (00:05:03) revealing a cross-section of many of the (00:05:06) features we just went over (00:05:09) the more one learns about the human (00:05:12) brain that magnificent organ (00:05:14) and vessel for human imagination the (00:05:17) more one can (00:05:18) appreciate its complex structure so with (00:05:20) that sentiment i will leave you with a (00:05:22) bit more footage (00:05:23) of the brain in all its glory (00:06:04) [Music] (00:06:16) [Music] (00:06:19) do (00:06:37) [Music] (00:06:46) [Music] (00:06:51) thanks for watching subscribe to my (00:06:53) channel for more tutorials support me on (00:06:55) patreon so i can keep making content (00:06:57) and as always feel free to email me (00:06:58) professor dave explains gmail.com (00:07:07) [Music] (00:07:20) you