NEUROSCIENCE & ANATOMY: The Complete
CNS/PNS Revision Masterclass
(2025/2026 Edition)
A Comprehensive High-Yield Guide to Nervous System
Structure, Function, and Clinical Assessment
Date: January 2026 Document Version: 1.1 (Updated for current curriculum)
DISCLAIMER: This document is for educational purposes only. It is a transformative
summary of course concepts and does not contain copyrighted exam questions or
university-owned slides.
© Newton Macharia | Page 1 of 24
,Table of Contents
Chapter 1: THE NERVOUS TISSUE............................................................................ 3
1.1 Overview of System Divisions.......................................................................... 3
I. Structural Divisions: The Anatomy .................................................................. 3
II. Functional Divisions: The Logic ..................................................................... 4
1.2 The Action Potential ......................................................................................... 4
I. The Five Key Stages......................................................................................... 4
II. The Refractory Periods ................................................................................... 6
Chapter 2: ANATOMY OF THE CNS ........................................................................... 8
2.1 The Brain Regions ............................................................................................ 8
A. The Cerebrum ................................................................................................. 8
B. The Diencephalon ........................................................................................... 9
2.2 Protective Structures ........................................................................................ 9
A. The Meninges.................................................................................................. 9
B. CSF Flow and the Ventricular System.......................................................... 10
Chapter 3: SOMATIC & AUTONOMIC ....................................................................... 13
3.1 Sensory vs. Motor Pathways .......................................................................... 13
A. Ascending Pathways (Sensory) ................................................................... 13
B. Descending Pathways (Motor) ..................................................................... 14
3.2 Sympathetic vs. Parasympathetic Comparison ............................................. 16
3.3 Reflex Arcs ...................................................................................................... 18
Chapter 4: THE NEUROLOGICAL EXAM ................................................................. 20
5.1 Clinical Assessment ....................................................................................... 20
A. Cranial Nerve Test (I through XII) ................................................................. 20
B. Coordination and Gait .................................................................................. 21
APPENDIX & REVIEW .............................................................................................. 23
6.1 High-Yield Glossary ........................................................................................ 23
References ............................................................................................................... 24
© Newton Macharia | Page 2 of 24
, Chapter 1: THE NERVOUS TISSUE
1.1 Overview of System Divisions
The nervous system is an incredibly complex communication network, categorized by
both its anatomy (structure) and its physiology (function). Understanding these
divisions is the first step to mastering neurobiology.
I. Structural Divisions: The Anatomy
The nervous system is physically divided into two major parts based on location:
• Central Nervous System (CNS): * Consists of the brain and the spinal cord.
o Acts as the "command center," processing all incoming sensory
information and issuing outgoing instructions.
• Peripheral Nervous System (PNS): * Includes all nervous tissue located
outside the CNS.
o Primarily composed of nerves (bundles of axons) and ganglia (clusters of
cell bodies) that link the rest of the body to the CNS.
© Newton Macharia | Page 3 of 24
CNS/PNS Revision Masterclass
(2025/2026 Edition)
A Comprehensive High-Yield Guide to Nervous System
Structure, Function, and Clinical Assessment
Date: January 2026 Document Version: 1.1 (Updated for current curriculum)
DISCLAIMER: This document is for educational purposes only. It is a transformative
summary of course concepts and does not contain copyrighted exam questions or
university-owned slides.
© Newton Macharia | Page 1 of 24
,Table of Contents
Chapter 1: THE NERVOUS TISSUE............................................................................ 3
1.1 Overview of System Divisions.......................................................................... 3
I. Structural Divisions: The Anatomy .................................................................. 3
II. Functional Divisions: The Logic ..................................................................... 4
1.2 The Action Potential ......................................................................................... 4
I. The Five Key Stages......................................................................................... 4
II. The Refractory Periods ................................................................................... 6
Chapter 2: ANATOMY OF THE CNS ........................................................................... 8
2.1 The Brain Regions ............................................................................................ 8
A. The Cerebrum ................................................................................................. 8
B. The Diencephalon ........................................................................................... 9
2.2 Protective Structures ........................................................................................ 9
A. The Meninges.................................................................................................. 9
B. CSF Flow and the Ventricular System.......................................................... 10
Chapter 3: SOMATIC & AUTONOMIC ....................................................................... 13
3.1 Sensory vs. Motor Pathways .......................................................................... 13
A. Ascending Pathways (Sensory) ................................................................... 13
B. Descending Pathways (Motor) ..................................................................... 14
3.2 Sympathetic vs. Parasympathetic Comparison ............................................. 16
3.3 Reflex Arcs ...................................................................................................... 18
Chapter 4: THE NEUROLOGICAL EXAM ................................................................. 20
5.1 Clinical Assessment ....................................................................................... 20
A. Cranial Nerve Test (I through XII) ................................................................. 20
B. Coordination and Gait .................................................................................. 21
APPENDIX & REVIEW .............................................................................................. 23
6.1 High-Yield Glossary ........................................................................................ 23
References ............................................................................................................... 24
© Newton Macharia | Page 2 of 24
, Chapter 1: THE NERVOUS TISSUE
1.1 Overview of System Divisions
The nervous system is an incredibly complex communication network, categorized by
both its anatomy (structure) and its physiology (function). Understanding these
divisions is the first step to mastering neurobiology.
I. Structural Divisions: The Anatomy
The nervous system is physically divided into two major parts based on location:
• Central Nervous System (CNS): * Consists of the brain and the spinal cord.
o Acts as the "command center," processing all incoming sensory
information and issuing outgoing instructions.
• Peripheral Nervous System (PNS): * Includes all nervous tissue located
outside the CNS.
o Primarily composed of nerves (bundles of axons) and ganglia (clusters of
cell bodies) that link the rest of the body to the CNS.
© Newton Macharia | Page 3 of 24
