brain and gross anatomy and function

Basic Anatomical Terms

  • Rostral: Towards the forehead.

  • Caudal: Towards the tail or bottom of the spinal cord.

Cerebrum

  • Cerebral (pertaining to the cerebrum):

    • Two hemispheres separated by a large fissure called the longitudinal fissure.

    • Covers various structures and functions of the brain.

Brain Structures

Gyri and Sulci

  • Gyrus (singular): Top of the hills.

  • Gyri (plural): Multiple hills on the brain's surface.

  • Sulcus (singular): Groove in the brain.

  • Sulci (plural): Multiple grooves on the brain's surface.

Corpus Callosum

  • Large structure connecting the right and left cerebral hemispheres.

  • Myelinated, appearing white in pictures.

Major Lobes of the Brain

  • Frontal Lobe: Involved in higher functions such as reasoning and planning.

  • Parietal Lobe: Processes sensory information.

  • Occipital Lobe: Responsible for vision.

  • Temporal Lobe: Near ear region; involves hearing and memory functions.

Central Sulcus

  • Divides the frontal lobe from the parietal lobe.

  • Important for understanding motor and sensory functions.

Brainstem

  • Composed of three main parts:

    • Medulla Oblongata: Vital life functions such as heart rate and respiration.

    • Pons: Connects lower brain structures to the higher brain.

    • Midbrain: Involved in functions like thirst and sleep cycles.

Cerebellum

  • Often referred to as the 'little brain'; situated below the cerebrum.

  • Responsible for motor coordination and balance.

  • Called arborvitae (tree of life) due to its tree-like appearance.

Choroid Plexus

  • Structure where cerebrospinal fluid (CSF) is produced, located in the ventricles of the brain.

Ventricular System

  • Consists of four ventricles:

    • Lateral Ventricles (right and left)

    • Third Ventricle: Lies between the lateral ventricles.

    • Fourth Ventricle: Located below the cerebellum.

  • Cerebral Aqueduct connects the third and fourth ventricles.

Cerebrospinal Fluid (CSF)

  • Clear, colorless liquid that fills the ventricles and surrounds the brain.

  • Provides buoyancy, making the brain weightless and protects it from injury.

  • Produced continuously by the choroid plexus and reabsorbed via the arachnoid granulations in the superior sagittal sinus.

Blood-Brain Barrier (BBB)

  • Formed primarily by astrocytes; regulates the passage of substances between the bloodstream and the brain.

  • Highly permeable to essential substances like glucose and oxygen but restricts many others, including some toxins.

Meninges

  • Layers covering the brain:

    • Dura Mater: Tough outer layer.

    • Arachnoid Mater: Spidery layer beneath the dura, with a subarachnoid space filled with CSF.

    • Pia Mater: Thin layer closely adhering to the brain's contours.

Function of Different Brain Areas

  • Frontal Lobe: Involved in personality, decision-making, and planning.

  • Parietal Lobe: Sensory processing; includes the postcentral gyrus (sensory) and precentral gyrus (motor).

  • Temporal Lobe: Language comprehension and auditory processing.

  • Occipital Lobe: Visual processing.

Limbic System

  • Associated with emotions, memory, and learning. Key structures include:

    • Amygdala: Involved in emotional control - fear and pleasure responses.

    • Hippocampus: Critical for memory and learning.

Conclusion

  • Understanding the brain's anatomy and functions is essential for studying neuroscience and psychology.

  • The interplay of different regions allows for complex behaviors and physiological regulation.