hello all it is your friend dr. Alsup again to talk about the basic structures of the brain now
I cannot emphasize enough how we are only going to discuss the very basics of the brain later
in your educational career you will go into some more final finer details of the brain in
your neurology sequence but for the purposes of this course we are going to highlight the
surrounding neurovascular structures associated with the brain and so we need to learn the basic
structures of the brain to help make those other areas make sense so let's get a look at the brain
we are going to start with a lateral view as you can see here and the largest component of
the brain consists of the cerebrum so basically all of this that I am outlining is the cerebrum
my lines are gorgeous as you can see now when you're looking at a lateral view you can only
see one of the two cerebral hemispheres but even when only looking at the one cerebral hemisphere
you can see how it is still the dominant feature of the brain the hemispheres will
be further subdivided into cerebral lobes what are which are used for descriptive purposes and
while named after bones they do not correspond precisely with where the bones are located so
as long as you understand the general areas of the lobes we will be happy we're not so into the
boundaries I'm just understanding the basics so the frontal lobe will be the most anterior with
the parietal lobe being more intermediate and the occipital lobe will be the most posterior and the
temporal lobes will be inferior so this is the temporal here it's going to be below this lateral
sulcus right here so frontal parietal occipital and temporal lobes and it's really this lateral
view that can show you all four of the the lobes you can also see nicely here this cerebellum the
cerebellum here which also has to him fears that like we saw with the cerebrum the cerebellum will
always be inferior to the cerebrum and posterior to the brainstem you can see a little bit of the
brainstem right here so this will be helpful in terms of getting yourself organized in terms
of anatomical relationships now looking to a superior view all you can see is the cerebrum
so all cerebrum all the time from the superior view you can actually see the two hemispheres
here so here is one hemisphere here is the other and it's going to be separated by this dominant
fissure or the longitudinal fissure the falx cerebri will sit in the longitudinal fissure
during life now this is going to be anterior this will be posterior so the frontal lobe is going to
be in this region it actually extends a ways further back him here ish so this means that
the parietal lobes will be here and the occipital lobe will be way back here alright so that's all
you can really see from the superior view alright moving on to an anterior view again the dominant
structure is the cerebrum with that longitudinal fissure here you can see the frontal lobes really
well from an anterior view with the temporal lobes here and here there's your other frontal
lobe now what is cool is we can start seeing some of the structures of the brainstem specifically
the pons here and you can see the basilar artery running right down the middle
and you can even see a little bit of the medulla oblongata here even though the vertebral artery
this particular vertebral artery is really blocking much of the view the other vertebral
arteries not quite quite as large in diameter in this particular donor now on to an inferior view
this will be anterior and the we'll be posterior and I knew that this was posterior because I can
see the cerebellum back here so that's one of the the ways that I get directed in terms of the view
here of the cerebrum you get a nice view of the frontal lobes here with the longitudinal fissure
here and it's kind of been separated a little bit due to the brain being moved to see certain
neurovascular structures also you can see the temporal lobes that are really being moved or
moved out of the way reflected out of the way in order to see the middle cerebral arteries here so
these are the temporal lobes you can also see portions of the brainstem you can see a little
bit of the midbrain but not enough to really focus on it here but you can see a beautiful
view of the pons with the basilar artery right here and the medulla oblongata here with the
vertebral arteries associated with that the cerebellum is located here inferior to the
cerebrum and posterior to the brainstem and you can finally see those two cerebellar hemispheres
located here and if I mix up the term cerebrum and cerebellum I am sorry they they always get
kind of jumbled up in my head so cerebrum is in this area and cerebellum is going to be located
back here lastly let's look at a Hemisected brain which means literally the brain was cut
right down the middle into right and left halves and now we are kind of looking at an internal view
of the brain so here is the cerebrum right here and the cerebellum is going to be in this area
we're only seeing one of the hemispheres for each one so once cerebral Hemisphere and one
cerebellar hemisphere this portion right here is referred to as the diencephalon you do not
need to identify this but since it is here I wanted to point it out this is often referred
to as the core of the brain which is not visible from an external view so composed of portions of
the thalamus specifically the dorsal thalamus and the hypothalamus so again you don't have
to identify this but it is kind of look is fairly obvious in this particular view now we really get
to see the portions of the brainstem well here is going to be the midbrain which will be the most
proximal or rostral here is the pons and this will be the medulla oblongata and this is the
medulla oblongata is going to be the most distally oriented or caudally oriented and if we move more
distally so if we kept going this way then we would be getting into the spinal cord so remember
that transition from medulla oblongata and spinal cord occurs right around the foramen magnum all
right so that is what we want you to identify on the brain for now knowing these basics will really
help with the vasculature and the cranial nerves that we are spending the majority of our time on
in this session as always feel free to reach out with any questions thank you for your time