Lesson Notes By Weeks and Term - Senior Secondary 2

TERM – 3^RD TERM

WEEK THREE

Class: Senior Secondary School 2

Age: 16 years

Duration: 40 minutes of 5 periods each

Date:

Subject: Biology

Topic: NERVOUS SYSTEM

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

1. Identify the organization of the nervous system
2. Differentiate between CNS and PNS

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

NOTE

NERVOUS COORDINATION

The nervous system is a complex network of specialized cells, tissues, and organs that coordinate and regulate various functions in the body. It enables communication between different parts of the body and processes information from both the external environment and internal conditions. The nervous system consists of two main components: the central nervous system (CNS), which includes the brain and spinal cord, and the peripheral nervous system (PNS), which extends throughout the body and connects to the CNS. Neurons, the fundamental units of the nervous system, transmit electrical and chemical signals to facilitate communication and control various physiological processes.

Organization of the nervous system

The nervous system is organized into two main components: the central nervous system (CNS) and the peripheral nervous system (PNS).

1. Central Nervous System (CNS): The central nervous system (CNS) is a crucial part of the nervous system and consists of two main components: the brain and the spinal cord.

       i. Brain:

   - The brain is the command center of the nervous system and is responsible for processing sensory information, thoughts, emotions, and coordinating various body functions.

   - It is divided into different regions, each with specific functions, such as the frontal lobe for decision-making and motor control, the temporal lobe for auditory processing, and the occipital lobe for vision.

       ii. Spinal Cord:

   - The spinal cord is a long, tubular structure that extends from the base of the brain down the vertebral column.

   - It serves as a pathway for nerve impulses traveling to and from the brain, facilitating communication between the brain and the rest of the body.

   - The spinal cord is also involved in reflex actions, allowing for rapid responses to certain stimuli without direct involvement of the brain.

2. The peripheral nervous system (PNS) is the part of the nervous system outside the central nervous system (CNS) and includes nerves that extend throughout the body. The peripheral nervous system acts as a communication network, transmitting information between the CNS and the rest of the body. It plays a crucial role in regulating bodily functions and responding to both external and internal stimuli.

The PNS can be further divided into two main subdivisions:

       i. Somatic Nervous System (SNS):

   - Responsible for voluntary control of skeletal muscles and the reception of external stimuli.

   - It enables conscious activities like walking, talking, and sensory perception.

       ii. Autonomic Nervous System (ANS):

   - Involuntary control of internal organs and glands.

   - Further divided into:

      a. Sympathetic Nervous System (SNS): Activates the "fight or flight" response, preparing the body for stressful situations by increasing heart rate, dilating pupils, etc.

      b. Parasympathetic Nervous System (PNS): Promotes the "rest and digest" response, helping the body relax and recover by slowing heart rate, constricting pupils, etc.

EVALUATION: 1. Describe nervous coordination

2. Describe the PNS as part of the nervous system
3. Describe the CNS as part of the nervous system

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively