CORONAL SECTIONS OF THE FOREBRAIN*

Plane c with neither labels nor arrows
This is a sagittal section throught the human brain and shows the right cerebral hemisphere from its medial aspect. It is presented here for orientation; i.e. to map the approximate plane of sectioning for the three sections (coronals) -- a, b and c -- shown below.
Plane a
 A coronal or frontal section through the human head runs parallel to the band on a headset. Plane a is through the middle of the frontal lobes (in front of the genu of the corpus callosum). This section exposes the interior of the frontal lobes several millimeters anterior to the forward reaches of the lateral ventricles. Thus the sections appear solid.
  1. right frontal lobe (arrowhead in white matter)
  2. longitudinal fissure
  3. left frontal lobe
  4. the numeral (4) rests on orbital gyri. The arrow points to gyri that curl over and follow the forward contour of the genu of the corpus callosum.The gyri in question are just visible here in the longitudinal fissue.
[For 3-dimensional perspective on the corpus callosum, click here.]
Plane b
This coronal section is through the rear of the frontal lobes (precentral gyri --primary motor cortex).
  1. temporal lobe (down to the reader's left)
  2. lateral (Sylvian) fissure
  3. insular cortex (Isle of Reil)
  4. claustrum (between external and "extreme" capsules)
  5. internal capsule (anterior limb)
  6. lateral ventricle (anterior or frontal horn)
  7. longitudinal fissure
  8. corpus callosum (body)
  9. septum pellicidum (medial wall of the lateral ventricle)
  10. caudate nucleus (head)
  11. lenticular nucleus (putamen)
  12. longitudinal fissure (between left and right sets of orbital gyri)
  13. olfactory tracts -- artifactually displaced here!

Want to test yourself without captions, Doc? Click here!
Plane c Coronal section at the level of the parental lobes
  1. temporal lobe (white matter)
  2. claustrum (thin ribbon of gray matter -- a basal nucleus)
  3. lenticular nucleus (putamen)
  4. longitudinal fissure
  5. corpus callosum (body) [for 3-D perspective, click here!]
  6. lateral ventricle (body)
  7. thalamus (left)
  8. internal capsule (posterior limb)
  9. external capsule
  10. insular cortex (isle of Reil)
  11. "extreme" capsule (not universally recognized)
  12. mass intermedia (traversing the slit-like 3rd ventricle
    between the right and left thalami
  13. the numeral (13) lies on the pons; the arrow points to the specimen's left
    mammilliary body; i. e., the posterior-inferior part of the
    hypothalamus
  14. the very tip of the arrow is in the 3rd ventricle
    (the lateral ventricles are 1 & 2)
  15. amygdaloid nucleus(no arrow); also called the
    amygdala. Note connections (both side) to the lenticular nuclei.

TO TEST YOURSELF ON PLANE C, CLICK HERE!
Plane b without Captions
 return to b with captions

Supply your own arrows
on this one, Doc!

Get me back to my arrows and captions!

To return to SOUND CONTROL click here!

* Plastic mounts of preserved specimens are from the Indiana University School of Optometry Human Brain Collection