a

cat brain

let's take a look at some cat brain

anatomy how I prefer to get the brain

out of the cranial cavity is actually

through the roof of the mouth I found

it's a lot easier you get a lot less

damage to the brain itself rather than

the traditional go through the top of

the skull with a saw and things like

that students tend to struggle with that

a little bit more so I actually follow

if you crack open the cat jaw just

follow that line with the saw back to

the base of the skull

and cut it off and then basically with

the Clippers and cut through the soft

palate get around to where the ears are

and all of those things actually I can

do a good job in harvesting the the cat

brain that way also in this case you're

going to find that the the brain itself

I've taken out the the maxilla and the

palatine bones and all that so you'll

actually see the the eyes in place and

then the nerves as they come out of the

nose and everything else and I'll remove

those as so you can see them as the

students would see them from there

harvesting so here we go with the cat

brain this is a little bit different

view than what a lot of people would

find with the brain because I have kept

on the the eyes and the nerves optic

nerves and everything else right here is

where we would find the nose you have

the nasal bones that come down and

divide in there I'll be pulling those

off and give you a view of what the

students would typically see when they

harvest this takes a little bit more

time to do but I thought it'd be kind of

neat to see some things in place I'm

going to flip this upside down and the

reason I kept this it looks like a mess

right here but the reason I kept this is

so you can see there are a bunch of

blood vessels obviously but you can see

where the true optic nerves will be

following here

and cross right here so you can see the

optic chiasma as it goes right there or

optic chiasm here's the other optic

nerve as we go here it's going to work

its way down obviously they're going to

be a bunch of muscles in fact you can

see the little tendons here that will

tie to that and be responsible for

moving those I haven't cut those away

either the optic nerve comes down here

and forms a little X now you can see

also the olfactory nerves as they come

down here and you'll see the lobe now

this brain looks a little pale in color

the reason for that is it has a fine

membrane over the top this membrane is

actually kind of a tough membrane and I

like to use that description because

it's the term for this literally means

tough mother is the tough mother of a

membrane that covers up the brain I'm

going to remove it cut it away you want

to be real careful as you do this so you

can see the underlying brain tissue

my little plug for the movie saw where

they cut into the brain do little

surgery good job guy doing that it's

pretty good science I don't know if I

would use my own hand grill or tools out

of the hardware store to do it but at

least it looked pretty realistic

now this tough mother membrane the dura

mater is there obviously protect the

brain to seal it off inside it's also

bacteria fighter bacteria have a tough

time no pun intended

getting through this membrane now you'll

notice that this membrane actually goes

down into the hemispheres of the brain

as well

so students have to be really careful

when cutting through there because they

can quite easily damage the brain it'll

go down through the hemispheres

separating off and compartmentalizing

each of the lobes now most often they'll

peel this operate with the skull as

they're removing now we get down to the

cerebellum we're also going to see it's

compartmentalised is that you should be

careful though is it going to pull the

brain apart it's very soft tissue very

easy to damage it will actually wrap

around and you'll see that this will all

come off in one sheet now as it does

most often what happens is the olfactory

Lopes will come off with it I fully

expect that to happen

so this is the view that most students

will have now you'll notice also the

optic nerves will start coming off with

it so you can see all of these things

are being protected

by the dura mater now you can see some

blood vessels in there okay that means

that tells us that we're in there

arachnoid space there's actually another

layer right on the brain itself we've

taken off the tough draw mater

is actually another layer right here of

the arachnoid layer this is the layer in

which we have the blood vessels now the

brain itself doesn't have any nerve or

pain receptors I should say obviously

it's a brain so it's going to have nerve

receptors but it doesn't have pain

receptors so a headache actually is not

the brain hurting what it is is a

problem with blood vessels and things

like that in fact most pain relievers

are actually just meant to alleviate

problems with blood vessels flying up

tonight let's take a look at some of the

structures of the brain this is just a

general overview we're not going to go

into specifics with different regions of

the lobes and things like that but here

is the typical cat brain it's very

similar to what the human in have we've

got the frontal lobe okay we've got

right and left hemispheres this is going

to be the left hemisphere this is going

to be the right hemisphere and you'll

notice that there the brain is

convoluted it has these ridges in fact

there's one more layer right here

underneath the arachnoid space and

that's called the pia mater

pa means little there's a little

membrane and I'm not going to waste time

in and cutting those but there is a

little membrane that covers the surface

of the brain itself so you can see that

this brain as it's convoluted actually

has three dimensions to it the high

points of this convolution all of these

ridges up on top of the hill these are

the gyrus and down in the valleys and

these low points down in here these the

sulcus or the sulky

okay so high points are the gyrus low

points are the sulcus we've got the

cerebrum now the cerebrum is therefore

obviously learning for conscious thought

for social judgment and things like that

if I flip it over on this we're going to

see where the olfactory lobes were okay

so this is the olfactory bulb as it

comes in we had the optic remember the I

lived right here and right here

these optic nerves will come down and

form an X right here and right here okay

that's the optic chiasm where these

nerves will actually cross where they're

going is to the back of the brain to the

back of the frontal lobe of the brain we

also see a little bit of the pituitary

gland okay the hypothesis is another

name for that that's the pituitary gland

and a lot of times that's going to come

off like this now underneath we'll find

where the mammillary body is mammillary

body of the I should back up the the

hypothesis or the pituitary gland is

there for most of the more complex

hormone secretions but underneath will

find the mammillary body which is for

more primal functions for more

homeostasis problems okay we've got

other lobes but these are all frontal

here's where we find the back part of

the brain is called the cerebellum and

this will lead out to the brain stem the

cerebellum is there for more

coordination and balance organization I

can actually lift this down a little bit

so you can see the midbrain region and

we'll take a look at those and functions

of the midbrain later on but that's

going to be more primitive functions a

lot of hormone secretion if I flip this

over and again the orientation with the

frontal lobe we have the olfactory we

have the optic chiasm now I've taken the

hypothesis away so we're going to see

where the mammillary body would sit

these right here by definition

would be the brainstem right at the

pointer and basically if I were to

follow down this way it becomes almost a

horizontal type of structure this region

right here notice I said region not

specific structure this region right

here is going to be the pons region okay

as we work our way back here it's more

almost rectangular this is the reticular

activating system the pond sits right on

top the reticular activating system

would be right here reticular activating

system is going to be more structured

for a filter we used to think that the

brain would be like a sponge or things

like that actually what we have is the

reticular activating system decides for

the brain what the process is all the

stimulus coming into the brain at once

what is important what needs to be

thought about what just needs to be

dealt with what do we need how do we

need to react and so on reticular

activating system is a strong part of

that and the pons is the distributing

center sends it on its way where it

needs to go what part of the brain what

it basically needs to once it gets past

the reticular activating system which

decides let it in the information into

the brain the pend says okay where do we

need to send this to respond properly

you