Now we will look at the brain
again from the same three perspectives and apply common terms for
refering to direction in brain navigation.
Rostral means
toward the
front, or nose, of the animal. Moving rostrally would mean moving
to the left in this picture.
Caudal means
toward the tail of the
animal. So moving caudally would
mean toward the right in this
picture.
You can also look dorsally
and
ventrally in
this image. Moving dorsally
would mean moving toward
the back of the animal. The dorsal
surface of the brain is at the
top of this picture.
Moving ventrally would mean
moving toward
the chest of the animal. The ventral
surface of this brain is at
the bottom of the picture.
The last major axis of the brain,
medial and
lateral, must
await the next plate. To give you a
hint, however, you are looking at the lateral
surface of the brain in
this image.
The cerebrum is
at the rostral end
of the brain and the brain
stem extends to the
caudal end. The
cerebellum
sits on the dorsal surface
of the
brain stem. If you
can say the preceeding two sentences rapidly, you're beginning to
talk like a neuroanatomist! Practice using these
terms until they come easily to you; impress your friends.
Whenever the dorsal/ventral plane,
or axis, of the brain can be seen in this guide, the dorsal
surface of the brain will be up
on the
screen and the ventral surface
will be down,
The sheep is a quadruped and
you're a biped (me too!). Because we stand on two legs and still
like to see where we're going, our nervous system has taken a bend near
the top so our eyes and some other head parts can aim forward.
Because of this bend in our "neuraxis," orientation terms differ a bit
in humans versus those that are appropriate in the sheep.
Most
users of this guide do not have an intrinsic interest in sheep. Rather,
the sheep brain serves as an accessable and effective tool for learning
about the structure of the human brain. Because of this, some
poetic license has been
taken in labeling certain structures and human terminology has been
"inaccurately" incorporated. Our apologies to the purists.