Divisions of the Brain: Forebrain, Midbrain, Hindbrain

Overview

• The brain can be divided into three main regions: the forebrain, midbrain, and hindbrain.
• These divisions are based on developmental and functional organization.

Functions of Each Brain Division

Forebrain (Prosencephalon)

• Largest part of the mammalian brain.
• Consists of the cerebral cortex which includes the cerebral hemispheres.
• Cerebral Cortex:
  • Frontal Lobe: Involves voluntary movement, reasoning, impulse control, language, and speech. Includes Broca's Area for speech production.
  • Parietal Lobe: Processes touch, limb position, and spatial awareness. Damage affects opposite side of the body.
  • Temporal Lobe: Processes auditory stimuli; includes Wernicke’s area for language comprehension. Works with the hippocampus for memory.
  • Occipital Lobe: Visual processing center; damage can cause visual impairments.
• Corpus Callosum: Connects the two brain hemispheres.
• Limbic System: Includes:
  • Thalamus: Sensory relay (except smell).
  • Hypothalamus: Regulates body temperature, hunger, and the endocrine system.
  • Amygdala: Processes emotions, especially fear.
  • Hippocampus: Involved in memory formation.
• Clinical Examples: Phineas Gage’s personality change and H.M.'s memory loss highlight the forebrain's roles.

Midbrain (Mesencephalon)

• Located on top of the brainstem.
• Functions:
  • Auditory and visual processing.
  • Eye movement coordination.
• Structures:
  • Colliculi: Process visual and auditory signals.
  • Tegmentum: Involved in movement coordination and alertness.
  • Cerebral Peduncles: Play a role in the central nervous system.

Hindbrain (Rhombencephalon)

• Extension of the spinal cord.
• Includes the medulla oblongata, pons, and cerebellum.
• Medulla Oblongata:
  • Manages autonomic functions like breathing and heart rate.
• Pons:
  • Involved in sleep, motor control, and arousal.
• Cerebellum:
  • Coordinates balance and movement, processes procedural memory.

FAQs

What is the forebrain?

• Largest part of the brain including the cerebrum, thalamus, and hypothalamus.
• Responsible for sensory processing, cognition, language, motor functions, and regulating emotions.

What does the forebrain do?

• Handles sensory perception, cognition, language generation and comprehension, motor control. Regulates temperature, reproductive functions, sleep, eating, and emotional displays.

References

• Typical references include studies on brain anatomy and functions, such as works by Harlow, Bailey, and others focusing on the brain's physical and psychological functions.