Nervous System Basics

Central Nervous System (CNS)

• Consists of the brain and spinal cord
• Protected by the blood-brain barrier
• Functions:
  • Integration of sensory information
  • Control of voluntary movements
  • Regulation of body functions (e.g. heart rate, blood pressure)

Brain

• Divided into three main parts:
  1. Cerebrum: largest part, responsible for sensory perception, movement, and higher-level cognitive functions
  2. Cerebellum: coordinates muscle movements, balance, and posture
  3. Brainstem: connects cerebrum to spinal cord, regulates basic functions (e.g. breathing, heart rate)

Spinal Cord

• Extends from base of brain down to lower back
• Functions:
  • Transmits messages between brain and peripheral nervous system
  • Controls reflexes

Peripheral Nervous System (PNS)

• Consists of nerves that connect CNS to rest of body
• Divided into two subsystems:
  • Somatic Nervous System: controls voluntary movements, transmits sensory information
  • Autonomic Nervous System: controls involuntary functions (e.g. heart rate, digestion)

Nerve Structure

• A nerve consists of:
  • Dendrites: receive signals from other neurons
  • Cell Body: contains nucleus and maintains cell function
  • Axon: carries signals away from cell body
  • Myelin Sheath: insulates and speeds up signal transmission

Glial Cells

• Support cells that provide structure and maintenance for neurons
• Types:
  • Astrocytes: provide nutrients, remove waste
  • Oligodendrocytes: produce myelin sheath
  • Microglia: immune system cells that protect CNS

Test your knowledge of the central and peripheral nervous systems, including the brain, spinal cord, neurons, and glial cells. Learn about their structures, functions, and interactions.