274 Neuroanatomy: Draw It to Know It
Cerebral Hemisphere — Lateral Face
Here, we will draw the lateral face of the cerebrum. First,
draw the lateral aspect of a cerebral hemisphere and show
the Sylvian fi ssure (aka the lateral sulcus) along a diago-
nal. Th en, draw the central sulcus from the top of the
brain to the Sylvian fi ssure. Label the area anterior to
the central sulcus as the frontal lobe. Next, label the pre-
occipital notch along the posterior undersurface of the
brain and then the parieto-occipital sulcus along the
superior convexity of the brain; note that the parieto-
occipital sulcus terminates abruptly in the superolateral
convexity — on the contrary, the parieto-occipital sulcus
is prominent on the medial surface of the brain. Now,
dot a vertical line from the termination of the parieto-
occipital sulcus to the pre-occipital notch and label it as
the lateral parietotemporal line. Posterior to this imagi-
nary line, label the occipital lobe. Next, dot a roughly
horizontal line from the posterior end of the Sylvian fi s-
sure to the middle of the anterior border of the occipital
lobe and label this line as the temporo-occipital line.
Superior to this line, label the parietal lobe, and inferior
to it, label the temporal lobe. We have now drawn the
four cerebral lobes visible on the lateral surface of the
brain; the fi ft h lobe, the limbic lobe, is present only on
the brain’s inferior and medial surfaces.
Next, let’s draw the g yri and sulci of the lateral surface
of the brain. Redraw a lateral hemisphere and include
the central sulcus and Sylvian fi ssure. Divide the anterior
frontal lobe into three horizontally distributed g yri using
two parallel sulci. Label the top sulcus as the superior
frontal sulcus and the bottom sulcus as the inferior fron-
tal sulcus. Th en, indicate that the superior frontal g yrus
lies above the superior frontal sulcus; that the middle
frontal g yrus lies in between the superior and inferior
frontal sulci; and that the inferior frontal g yrus lies in
between the inferior frontal sulcus and the inferior
border of the frontal lobe. Note that the inferior frontal
g yrus is triangular, and it contains pars orbitalis, pars tri-
angularis, and pars opercularis divisions.
Now, let’s draw the g yri and sulci of the lateral tempo-
ral lobe. Again draw two sulci — label the top sulcus as
the superior temporal sulcus and the bottom sulcus as
the inferior temporal sulcus. Th en, label the superior
temporal g yrus above the superior temporal sulcus; the
middle temporal g yrus in between the superior and
middle temporal sulci; and the inferior temporal g yrus
below the inferior temporal sulcus.
Next, let’s draw a similar arrangement for the occipi-
tal g yri of the lateral surface of the brain. Draw the supe-
rior occipital sulcus (aka the intraoccipital sulcus), which
follows the path of the intraparietal sulcus (drawn later),
and then draw the inferior occipital sulcus, which fol-
lows the path of the inferior temporal sulcus. Above the
superior occipital sulcus, label the superior occipital
g yrus; in between the superior and inferior occipital
sulci, label the middle occipital g yrus (aka the lateral
occipital g yrus); and below the inferior occipital sulcus,
label the inferior occipital g yrus. Th e middle occipital
g yrus is the largest of the occipital g yri on the lateral sur-
face of the brain, and it is sometimes subdivided into
superior and inferior g yri.
Now, label the basal, anterior surface of the frontal
lobe as the orbitofrontal cortex. Th en, in the posterior
aspect of the frontal lobe, draw the precentral sulcus,
and in between it and the central sulcus, label the pre-
central g yrus, which is the primary motor area.
Next, let’s draw the g yri and sulci of the parietal lobe.
First, draw the postcentral sulcus, and in between it and
the central sulcus, label the postcentral g yrus, which is
the primary sensory area. Th en, draw the intraparietal
sulcus, and show that it divides the remainder of the
parietal lobe into the superior parietal lobule, superiorly,
and the inferior parietal lobule, inferiorly — the inferior
parietal lobule divides into the supramarginal g yrus and
angular g yrus. Th e supramarginal g yrus caps the poste-
rior end of the Sylvian fi ssure and the angular g yrus caps
the posterior end of the superior temporal sulcus.^1 – 6