🔑 Key Definitions
Telencephalon: Anterior part of forebrain; develops into cerebral cortex and basal ganglia
Diencephalon: Posterior part of forebrain; becomes thalamus and hypothalamus
Mesencephalon: Midbrain; contains tectum and tegmentum
Encephalization: Evolutionary trend toward larger, more complex forebrain relative to body size
Diencephalon: Posterior part of forebrain; becomes thalamus and hypothalamus
Mesencephalon: Midbrain; contains tectum and tegmentum
Encephalization: Evolutionary trend toward larger, more complex forebrain relative to body size
📊 Five Secondary Brain Divisions
- Telencephalon (Forebrain): Cerebral cortex, basal ganglia, limbic system
- Diencephalon (Forebrain): Thalamus, hypothalamus, epithalamus
- Mesencephalon (Midbrain): Tectum, tegmentum, substantia nigra
- Metencephalon (Hindbrain): Pons, cerebellum
- Myelencephalon (Hindbrain): Medulla oblongata
🧠 Hindbrain Structures
- Medulla Oblongata: Controls vital functions (heart rate, breathing, blood pressure)
- Pons: "Bridge" connecting cerebellum to rest of brain; involved in sleep and arousal
- Cerebellum: Motor coordination, balance, timing; damage causes ataxia
- Reticular Formation: Runs through hindbrain and midbrain; regulates consciousness and attention
📈 Developmental Organization
- 3 Primary Vesicles: Prosencephalon (forebrain), Mesencephalon (midbrain), Rhombencephalon (hindbrain)
- 5 Secondary Vesicles: Forebrain splits into telencephalon + diencephalon; hindbrain splits into metencephalon + myelencephalon
- Encephalization: Humans have highly developed telencephalon (cerebral cortex)
💡 Exam Tips
- Remember division hierarchy: 3 primary → 5 secondary vesicles
- Forebrain has TWO parts: TELencephalon + DIencephalon
- Hindbrain has TWO parts: METencephalon + MYELencephalon
- Medulla = vital functions (damage = death)
- Encephalization = evolutionary expansion of forebrain (especially cortex)
- Metencephalon = Pons + Cerebellum, Myelencephalon = Medulla only