Notes on the Cerebrum Anatomy

Overview of the Cerebrum

• The cerebrum is one of the four main divisions of the brain, encompassing the upper brain structures.
• It can be divided into left and right hemispheres.

Anatomy of the Cerebrum

• Fissures:

• Longitudinal Fissure:

  • The deep groove that separates the left and right hemispheres of the cerebrum.
  • Contains the falx cerebri, a piece of dura mater.
  • Hosts the superior sagittal sinus in its groove.

• Transverse Fissure:

  • The fissure that separates the cerebrum from the cerebellum.

• Sulci and Gyri:

• Sulci:

  • Shallow grooves on the surface of the cerebrum.
  • Plural form: sulci, singular: sulcus.

• Gyri:

  • Raised areas found between the sulci.
  • Plural form: gyri, singular: gyrus.

Lobes of the Cerebrum

• The cerebrum is divided into five distinct lobes:

1. Frontal Lobe:
   • Located at the front, corresponds to the frontal bone of the skull.
2. Parietal Lobe:
   • Situated at the top, corresponds to the parietal bone.
3. Temporal Lobe:
   • Located on the side, corresponding to the temporal bone.
4. Occipital Lobe:
   • Found at the back of the head, corresponding to the occipital bone.
5. Insula:
   • A hidden lobe deep to the temporal lobe, recently identified in anatomy studies.
   • Named after the Latin word for island; requires pulling back the temporal lobe to see it.

Hemisphere Structure

• Each hemisphere has matched pairs of lobes:
• Left frontal, right frontal
• Left parietal, right parietal
• Left temporal, right temporal
• Left occipital, right occipital
• Left insula, right insula

Key Sulci and Gyri

• Key sulci to remember:

1. Central Sulcus:
   • Separates the frontal lobe from the parietal lobe.
   • Precentral Gyrus: The gyrus located anterior (in front) to the central sulcus.
   • Postcentral Gyrus: The gyrus located posterior (behind) to the central sulcus.
2. Lateral Sulcus (Lateral Fissure):
   • Separates the frontal and parietal lobes from the temporal lobe.
3. Parieto-Occipital Sulcus:
   • Divides the parietal lobe from the occipital lobe.

Conclusion

• Understanding these anatomical features is foundational before exploring the functional aspects of the different lobes in the next module.