Unit 1: Nervous System

February 20, 2026

Semester 2
BP201T

Introduction to Nervous System

Unit 1 covers the master control system of the body: The Nervous System. It explores how neurons communicate via electricity (Action Potential) and chemicals (Neurotransmitters). You will study the intricate structure of the Brain (Cerebrum, Cerebellum, Brain Stem) and the Spinal Cord, understanding how we think, move, and react to the world.

Syllabus & Topics

  • 1Organization of nervous system, neuron, neuroglia.
  • 2Classification and properties of nerve fibre.
  • 3Electrophysiology, action potential, nerve impulse.
  • 4Receptors, synapse, neurotransmitters.
  • 5Central nervous system: Meninges, ventricles of brain and cerebrospinal fluid.
  • 6Structure and functions of brain (cerebrum, brain stem, cerebellum).
  • 7Spinal cord (gross structure, functions of afferent and efferent nerve tracts, reflex activity).

Learning Objectives

Draw the Neuron: Label the parts of a neuron and explain the function of myelin sheath.
Explain Action Potential: Describe the phases of depolarization, repolarization, and hyperpolarization.
Map the Brain: Identify the lobes of the cerebrum and their primary functional areas.
Understand Reflexes: Draw a reflex arc and explain its components.
Describe CSF: Explain the formation, circulation, and function of Cerebrospinal Fluid.

Frequently Asked Questions (FAQs)

Q1. What is the difference between Afferent and Efferent nerves?

Afferent (sensory) nerves carry signals from the body to the brain.
Efferent (motor) nerves carry signals from the brain to the muscles or glands.

Q2. Why is the Action Potential important?

An action potential is the fundamental electrical signal that enables neurons to communicate. Without it, processes such as thought, movement, and sensation would not occur.

Q3. How do I remember the Cranial Nerves?

You can use mnemonics to remember them. A common one is:
“On Old Olympus Towering Top, A Finn And German Viewed Some Hops.”

Q4. What are Neuroglia?

Neuroglia (glial cells) are the supporting cells of the nervous system. They do not conduct nerve impulses but provide nutrition, protection, insulation, and structural support to neurons.

Q5. What is a Reflex Arc?

A reflex arc is the neural pathway responsible for a reflex action. It consists of:
Receptor → Sensory Neuron → Integration Center (CNS) → Motor Neuron → Effector (Muscle/Gland).