324 Neuroanatomy: Draw It to Know It
Leptomeningeal Cerebral Arteries
We divide the arterial supply of the cerebral hemi-
spheres into the superfi cial, leptomeningeal arterial
branches and the deep, perforating arterial branches.
Here, we will address the vascular territories of the lep-
tomeningeal branches, which emanate from the anterior,
middle, and posterior cerebral arteries, and we will also
address the anterior choroidal artery. Note that because
there is vast interpatient variability in the vascular terri-
tories, we should pay closer attention to the general vas-
cular territory of each vessel than its specifi c territorial
borders.
Begin with axial sections through the cerebrum at
three diff erent vertical heights: superior, middle, and
inferior. To denote the mid-vertical cerebrum, include
the lateral ventricles at the level of the body of the cau-
date nucleus, and to denote the inferior cerebrum,
include the midbrain. First, at the superior level, show
that the anterior cerebral artery (ACA) supplies the
medial one third of the superior cerebrum and that the
middle cerebral artery (MCA) supplies the lateral two
thirds. For reference, indicate that the superior frontal
sulcus separates the MCA and ACA supply. Next, at the
mid-vertical level, show that the ACA supplies the
medial one third of the hemisphere and that the MCA
supplies the lateral two thirds, and also indicate that the
posterior cerebral artery (PCA) supplies a small portion
of the posterior cerebral hemisphere. For reference, indi-
cate that the parieto-occipital sulcus is the anterior
boundary of the PCA. Now, indicate that at the inferior
level, the ACA covers the medial one third of the
cerebrum only as far posterior as the Sylvian fi ssure, and
show that the MCA covers the lateral two thirds of the
hemisphere — the MCA territory terminates just poste-
rior to the medial-lateral axis of the posterior midbrain.
Th en, show that the PCA covers the posterior cerebrum.
Lastly, indicate that the superfi cial portion of the ante-
rior choroidal artery covers the medial temporal lobe.
Now, let’s draw the arterial territories in sagittal view.
Draw both the lateral and medial faces of the cerebrum.
Show that the MCA supplies the majority of the lateral
cerebral hemisphere, except for a strip of the antero-
superior hemisphere, which the ACA supplies, and also
a strip of the postero-inferior hemisphere, which the
PCA supplies. Next, let’s address the medial hemisphere;
draw a diagonal line from the parieto-occipital sulcus to
the anterior pole of the temporal lobe. Show that the
ACA supplies the antero-superior hemisphere and that
the PCA supplies the postero-inferior hemisphere, and
also indicate that the anterior choroidal artery supplies
the medial temporal lobe.^1 , 2 , 4 – 6