Lesson Note on Peripheral Nervous System: Somatic and Autonomic Division for SSS 2

Class: Senior Secondary School 2 (SS2 / SSS 2)
Term: 3rd Term
Week: 5
Age: 16 years
Duration: 45 minutes
Subject: Biology
Curriculum Theme: Regulation and Control
Previous Lesson: Central Nervous System: Brain and Spinal Cord.
Topic: THE PERIPHERAL NERVOUS SYSTEM (PNS)
Subject Matter: Flow chart representing the different parts of the PNS, somatic nervous system, autonomic nervous system, sympathetic nervous system and parasympathetic nervous system

Specific Objectives

By the end of the lesson, pupils should be able to:

Cognitive Domain:

• Define the Peripheral Nervous System (PNS).
• Identify the major divisions of the PNS.
• State the functions of the somatic and autonomic nervous systems.
• Differentiate between the sympathetic and parasympathetic nervous systems.

Affective Domain:

• Appreciate the importance of the PNS in coordinating body functions.
• Show interest in learning about the different components of the human nervous system.

Psychomotor Domain:

• Draw a simple flow chart illustrating the divisions of the PNS.
• Present the differences between the sympathetic and parasympathetic nervous systems in a tabular form.

Social Domain:

• Collaborate with peers during discussions on the nervous system.
• Share their understanding of PNS functions with the class.

Reference Materials

The following resources were used in planning this lesson:

• Senior Secondary Schools Education Curriculum
• State Unified Scheme of Work
• Modern Biology for Senior Secondary Schools by Sarojini T. Ramalingam

Instructional Materials

The teacher will teach this lesson with the aid of:

• Biology textbook
• Posters showing the human nervous system
• Diagrams illustrating the divisions of the PNS

Rationale for the Lesson

This lesson helps pupils understand how the peripheral nervous system connects the central nervous system to the rest of the body. It enables pupils to grasp how different parts of the body communicate with the brain and spinal cord, influencing both voluntary and involuntary actions essential for daily life.

Prerequisite/Previous Knowledge

Pupils should have prior knowledge of the central nervous system (CNS) and the general structure and function of the human nervous system.

Lesson Content/Board Summary

THE PERIPHERAL NERVOUS SYSTEM (PNS)

Definition of the Peripheral Nervous System (PNS)

The Peripheral Nervous System (PNS) consists of all the nerves and ganglia outside the brain and spinal cord. It connects the Central Nervous System (CNS) to sensory organs, muscles, blood vessels, and glands, allowing for communication between the CNS and the rest of the body.

Divisions of the PNS

The PNS is broadly divided into two main parts:

• Somatic Nervous System (SNS): Controls voluntary movements.
• Autonomic Nervous System (ANS): Controls involuntary bodily functions.

This can be represented as a flow chart:

Peripheral Nervous System (PNS)

|——-|——-|

Somatic Nervous System (SNS) Autonomic Nervous System (ANS)

|——-|——-|

Sympathetic Nervous System Parasympathetic Nervous System

Somatic Nervous System (SNS)

The Somatic Nervous System is responsible for voluntary control of body movements. It transmits sensory information from the skin, muscles, and sensory organs to the CNS and motor commands from the CNS to the skeletal muscles.

Functions:

• Receives sensory input from the external environment (e.g., touch, temperature, pain).
• Controls skeletal muscles for voluntary actions (e.g., walking, writing, lifting).

Autonomic Nervous System (ANS)

The Autonomic Nervous System regulates involuntary physiological processes, such as heart rate, digestion, respiration, salivation, perspiration, and sexual arousal. It operates without conscious thought.

Divisions of the ANS:

• Sympathetic Nervous System: Prepares the body for “fight or flight” responses.
• Parasympathetic Nervous System: Promotes “rest and digest” activities.

Sympathetic Nervous System

The sympathetic nervous system is activated in situations of stress or danger. It mobilizes the body’s resources to respond to perceived threats.

Effects on the body:

• Increases heart rate and blood pressure.
• Dilates pupils.
• Inhibits digestion.
• Relaxes bronchi (widens airways).
• Stimulates glucose release from the liver.
• Increases blood flow to skeletal muscles.

Parasympathetic Nervous System

The parasympathetic nervous system is responsible for conserving energy and promoting normal bodily functions during periods of rest. It counteracts the effects of the sympathetic system.

Effects on the body:

• Decreases heart rate and blood pressure.
• Constricts pupils.
• Stimulates digestion and absorption of food.
• Constricts bronchi (narrows airways).
• Stimulates salivation and tear production.

Differences between Sympathetic and Parasympathetic Nervous Systems

The sympathetic and parasympathetic nervous systems have opposing effects on the body’s organs:

Sympathetic Nervous System:

• Prepares the body for “fight or flight” responses.
• Increases heart rate.
• Increases blood pressure.
• Dilates pupils.
• Inhibits digestion.
• Relaxes airways (bronchodilation).
• Stimulates adrenaline release.

Parasympathetic Nervous System:

• Promotes “rest and digest” activities.
• Decreases heart rate.
• Decreases blood pressure.
• Constricts pupils.
• Stimulates digestion.
• Constricts airways (bronchoconstriction).
• Conserves energy.

Teaching Methods/Instructional Techniques

Discussion, Lecture, Demonstration, Question and Answer, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher greets the pupils, reviews the previous lesson on the Central Nervous System (CNS), and then introduces the new topic, “The Peripheral Nervous System (PNS),” by asking pupils what they think connects the CNS to other body parts.
Pupils’ Activity: Pupils respond to the teacher’s questions and listen attentively to the introduction of the new topic.
Learning Point: Pupils recall previous knowledge and are prepared for the new lesson.

Step 2: Explanation of PNS and its divisions

Time: 8 minutes
Teaching Skill: Explanation/Illustration
Teacher’s Activity: The teacher defines the Peripheral Nervous System (PNS) and explains its two main divisions: the Somatic Nervous System (SNS) and the Autonomic Nervous System (ANS), using a diagram or poster.
Pupils’ Activity: Pupils listen, observe the diagrams, and copy notes on the definition and divisions of the PNS.
Learning Point: Pupils understand the basic structure and divisions of the PNS.

Step 3: The Somatic Nervous System

Time: 7 minutes
Teaching Skill: Explanation/Questioning
Teacher’s Activity: The teacher explains the Somatic Nervous System (SNS), focusing on its role in voluntary movements and transmitting sensory information. The teacher provides examples of voluntary actions.
Pupils’ Activity: Pupils listen, ask questions for clarification, and note down the functions of the SNS.
Learning Point: Pupils grasp the function of the SNS in voluntary control.

Step 4: The Autonomic Nervous System

Time: 7 minutes
Teaching Skill: Explanation/Discussion
Teacher’s Activity: The teacher explains the Autonomic Nervous System (ANS) and its role in involuntary body functions. The teacher introduces its two subdivisions: the sympathetic and parasympathetic nervous systems.
Pupils’ Activity: Pupils listen and participate in a brief discussion on involuntary actions in the body.
Learning Point: Pupils understand the ANS as the controller of involuntary functions and its subdivisions.

Step 5: Sympathetic Nervous System

Time: 6 minutes
Teaching Skill: Elaboration/Examples
Teacher’s Activity: The teacher elaborates on the sympathetic nervous system, explaining its “fight or flight” response and providing examples of its effects on various organs during stressful situations.
Pupils’ Activity: Pupils listen to the explanations and contribute examples of situations where the sympathetic system might be activated.
Learning Point: Pupils understand the role and effects of the sympathetic nervous system.

Step 6: Parasympathetic Nervous System

Time: 7 minutes
Teaching Skill: Elaboration/Comparison
Teacher’s Activity: The teacher explains the parasympathetic nervous system, highlighting its “rest and digest” functions and its contrasting effects compared to the sympathetic system. The teacher guides pupils to identify these differences.
Pupils’ Activity: Pupils listen, identify the contrasting effects, and prepare to tabulate the differences.
Learning Point: Pupils understand the role and effects of the parasympathetic nervous system and begin to compare it with the sympathetic system.

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

1. Define the Peripheral Nervous System (PNS).
2. List the two main divisions of the PNS.
3. State two functions of the Somatic Nervous System.
4. Mention three differences between the sympathetic and parasympathetic nervous systems.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 2 minutes
Teaching Skill: Summarization
Teacher’s Activity: The teacher summarizes the key points of the lesson, reiterating the importance of the PNS and its subdivisions in coordinating body functions. The teacher assigns homework for pupils to draw a detailed flow chart of the PNS and its divisions.
Pupils’ Activity: Pupils listen to the summary and note down the homework.
Learning Point: Pupils consolidate their understanding of the lesson and receive further practice.

Lesson Keywords

• Peripheral Nervous System (PNS) – The part of the nervous system outside the brain and spinal cord.
• Somatic Nervous System (SNS) – Controls voluntary movements and transmits sensory information.
• Autonomic Nervous System (ANS) – Regulates involuntary body functions.
• Sympathetic Nervous System – Prepares the body for “fight or flight” responses.
• Parasympathetic Nervous System – Promotes “rest and digest” activities.
• Ganglia – Clusters of nerve cell bodies outside the CNS.

Differentiation

For pupils who grasp concepts quickly, the teacher can encourage them to research specific nerve pathways or common disorders affecting the PNS. For pupils needing additional support, the teacher can provide simplified diagrams and offer one-on-one explanations, focusing on key definitions and the main divisions of the PNS.

Note for teachers using this lesson plan

Teachers should ensure to use clear and labelled diagrams of the nervous system to aid understanding. Encourage pupils to draw their own flow charts and tables, as this reinforces learning. Emphasize the opposing yet complementary roles of the sympathetic and parasympathetic nervous systems with relatable examples.