Brain Anatomy: Lobes and Gyri

Four Main Lobes of the Brain

• Frontal Lobe
• Parietal Lobe
• Temporal Lobe
• Occipital Lobe

Central Sulcus

• Divides the frontal and parietal lobes.
• Precentral Gyrus: Located on the frontal lobe side.
• Postcentral Gyrus: Located on the parietal lobe side.

Gyri in Each Lobe

Frontal and Temporal Lobes

• Frontal Lobe Gyri:

  • Superior Frontal Gyrus
  • Middle Frontal Gyrus
  • Inferior Frontal Gyrus

• Temporal Lobe Gyri:

  • Superior Temporal Gyrus
  • Middle Temporal Gyrus
  • Inferior Temporal Gyrus

Occipital Lobe

• Superior Occipital Gyrus
• Lateral Occipital Gyrus
• Inferior Occipital Gyrus

Detailed Examination of Gyri

Orbital Gyri

• Located near the eye socket.
• Inferior Frontal Gyrus is divided into:
  • Pars Orbitalis (near eye socket)
  • Pars Triangularis (triangle-shaped)
  • Pars Opercularis (unclear naming origin)

Parietal Lobe

• Superior Parietal Lobule
• Inferior Parietal Lobule:
  • Angular Gyrus
  • Supramarginal Gyrus

Medial Surface Gyri

• Cingulate Gyrus: Around the corpus callosum.
• Gyrus Rectus: Straight gyrus visible from the bottom view.
• Para Central Lobule: Contains the central sulcus.
• Cuneus and Precuneus: Separated by the parietal-occipital fissure.

Other Important Fissures

• Calcarine Fissure:
  • Cuneus: Lies on the superior bank.
  • Lingual Gyrus: Lies on the lower bank, tongue-shaped.

Additional Gyri

• Parahippocampal Gyrus: Ends at the uncus.
• Fusiform Gyrus (Occipital-Temporal Gyrus): Used for facial recognition.

Bottom View of the Brain

• Straight Gyrus: Name from its appearance.
• Superior Frontal Gyrus: At the anterior end.
• Orbital Gyri: Posterior to the superior frontal gyrus.
• Temporal Lobe Gyri:
  • Middle Temporal Gyrus
  • Inferior Temporal Gyrus
  • Fusiform Gyrus
  • Parahippocampal Gyrus

Occipital Lobe

• Lingual Gyrus
• Inferior Occipital Gyrus

Sylvian (Lateral) Fissure

• Heschl's Gyrus (Superior Transverse Temporal Gyri)
• Coronal cross-section highlights:
  • Parietal Operculum
  • Frontal Operculum
  • Orbital Operculum

Insula

• Contains long and short gyri of the insula.

Note: This lecture contained a lot of anatomical terminology and structural details, which are crucial for understanding brain anatomy and physiology. Study the relationships between these structures for a better grasp of their functions.