AP1

Brain Topics

Directional Terms

  • Rostral: Refers to a position toward the forehead.

  • Caudal: Indicates a position toward the spinal cord.

Important Anatomical Features

  • Longitudinal Fissure:

    • A deep groove that separates the cerebral hemispheres.

    • It runs in a sagittal direction (front to back, dividing left and right).

  • Gyri:

    • Thick folds on the brain surface often referred to as "hilltops."

  • Sulci:

    • Shallow grooves that exist between the gyri, commonly referred to as "valleys."

  • Corpus Callosum:

    • A thick nerve bundle located at the bottom of the longitudinal fissure.

    • Connects the right and left cerebral hemispheres.

    • Composed of white matter due to the presence of myelin.

Major Portions of the Brain

  • Cerebrum (Cerebral Hemispheres):

    • Represents approximately 83% of brain volume.

    • Features and landmarks include:

    • Gyri

    • Sulci

    • Longitudinal cerebral fissure

    • Corpus callosum

  • Cerebellum:

    • The second largest brain region.

    • Contains about 50% of the neurons, despite being only 10% of brain volume.

    • Located in the posterior cranial fossa.

    • Separated from the cerebrum by the transverse cerebral fissure.

  • Brainstem:

    • Comprises several structures including:

    • Diencephalon

    • Midbrain

    • Pons

    • Medulla oblongata

Surface Anatomy of the Brain

  • Superior View:

    • Shows the brain from above, revealing the layout and structure of the cerebrum and its lobes.

  • Lateral View:

    • Displays the brain from the side to highlight the cerebral structure, including lobes and fissures.

Lobes of the Brain

  • Frontal Lobe

  • Central Sulcus:

  • Parietal Lobe:

  • Occipital Lobe:

    • Important for processing visual information.

  • Cerebral Hemispheres:

    • The two halves of the cerebrum, separated by the longitudinal cerebral fissure.

Additional Structures Visible in Lateral View

  • Temporal Lobe:

  • Spinal Cord:

    • Connects the brain with the peripheral nervous system.

  • Cerebrum and Cerebellum:

    • Key components of the neural structure.