Brain Notes

The Brain

Brain Facts

  • Uses 20-30% of body's blood and oxygen.
  • Each brain cell connects with about 10,000 others.
  • Average brain weighs 1.4 kg and is 15 cm long.
  • Contains 100 billion neurons.

Role of the Brain

  • Command center controlling body parts and functions.
  • Most important part of the nervous system.
  • Located inside the skull for protection.

Brain Composition

  • Made of brain cells, with only 10% being neurons.
  • Other cells support and nourish neurons.

Cerebrum

  • Largest part of the brain, about 90% of its mass.
  • Responsible for thinking, memory, speaking, learning, and voluntary movements.

Regions of the Cerebrum

  • Frontal Lobe: Coordinates voluntary movements, impulse control, long-term memory, language, emotional regulation, and personality.
  • Temporal Lobe: Formation of visual memories, auditory processing, speech production, and language recognition.
  • Parietal Lobe: Perception of sensation (touch, temperature, pain), visual/auditory information, spatial awareness, and navigation.
  • Occipital Lobe: Vision, visual processing, shape recognition, and color perception.

Cerebrum Hemispheres

  • Left hemisphere controls the right side of the body; the right hemisphere controls the left side.
  • The hemispheres work together and communicate.

Cerebellum

  • Contains over half the brain's neurons but only 10% of its volume.
  • Controls posture, coordination, balance.
  • Processes motor messages.

Brainstem

  • Connects the brain to the spinal cord.
  • Involved in autonomic (involuntary) functions like breathing, heartbeat, blood pressure, and reflexes.