Brain Anatomy and Function

Overview of the Brain

• Central Nervous System (CNS): Composed of the brain and spinal cord.
• Functions: Controls thought, memory, emotion, touch, motor skills, vision, breathing, temperature, hunger, and body regulation.
• Composition: Weighs about 3 pounds; consists of 60% fat, with water, protein, carbohydrates, and salts. Contains blood vessels, neurons, and glial cells.

Gray and White Matter

• Gray Matter: Contains neuron somas (cell bodies).
• White Matter: Composed of axons wrapped in myelin.
• Functions: Gray matter processes information, white matter transmits information.

Brain Functionality

• Signal Transmission: Sends/receives chemical and electrical signals.
• Neuron Count: Billions of neurons facilitate communication.

Main Parts of the Brain

1. Cerebrum:
   • Largest brain part; regulates movement, temperature, speech, judgment, and senses.
   • Cerebral Cortex: Outer gray matter with folds; divided into two hemispheres connected by corpus callosum.
2. Brainstem:
   • Midbrain: Controls hearing, movement, and responses.
   • Pons: Connects midbrain and medulla; involved in facial expressions and balance.
   • Medulla: Controls vital functions like heart rhythm and breathing.
3. Cerebellum:
   • Coordinates voluntary movements, balance, and posture.

Brain Coverings: Meninges

• Dura Mater: Tough outer layer.
• Arachnoid Mater: Thin, weblike, with cerebrospinal fluid beneath.
• Pia Mater: Thin inner layer hugging the brain.

Brain Lobes

• Frontal Lobe: Involved in decision-making, personality, movement, and smell.
• Parietal Lobe: Interprets spatial relationships and touch.
• Occipital Lobe: Processes vision.
• Temporal Lobe: Handles memory, speech, and smell.

Deeper Brain Structures

• Pituitary Gland: Regulates hormones and glands.
• Hypothalamus: Controls temperature, hunger, and emotions.
• Amygdala: Regulates emotion and memory.
• Hippocampus: Supports memory and learning.
• Pineal Gland: Influences sleep-wake cycles.

Cerebrospinal Fluid and Ventricles

• Ventricles: Four cavities producing cerebrospinal fluid (CSF).
• CSF Functions: Cushions CNS, removes waste, delivers nutrients.

Blood Supply to the Brain

• Vertebral and Carotid Arteries: Supply blood to the brain.
• Circle of Willis: Ensures blood circulation among brain regions.

Cranial Nerves

• 12 Cranial Nerves: Include olfactory, optic, trigeminal, facial, vagus, and others, each with specific functions related to sensation and movement.

These notes provide a comprehensive overview of the brain's anatomy and its complex functions, covering critical aspects of brain structure, protective layers, lobes, deeper structures, and the cranial nerves.