DETAILED LESSON NOTE
Subject: Basic Science
Class: JSS 2 (Grade 8)
Topic: Circulatory System (2)
Sub-topic: The Heart, Blood Circulation, and Problems of the Circulatory
System
Duration: 40 minutes
Week: Eleven
Average Age of Students: 12 – 14 years
Class Size: To be inserted by the teacher
Date: To be inserted by the teacher
Instructional Materials:
- Chart/model of the human heart
- Diagram of blood circulation
- Marker and whiteboard
- Textbook
Lesson
Objectives
At the end of the lesson, students
should be able to:
- Identify and state the simple structure and two basic
functions of the human heart.
- Explain, with the aid of a diagram, how blood
circulates round the human body through systemic and pulmonary
circulation.
- Draw and label correctly a simple diagram showing the
circulation of blood in the human body.
- Predict what happens to the human body if blood
circulation is interrupted or incomplete.
- Analyze at least two common diseases of the circulatory
system and propose preventive measures.
Entry
Behaviour
Students already know that the heart
pumps blood, and blood carries oxygen and nutrients to different parts of the
body.
Set
Induction (5 minutes)
- Teacher asks: “What do you notice about your
heartbeat after you run fast or play football?”
- Expected answers: “It beats faster”, “We breathe
heavily”, “We feel tired quickly”.
- Teacher responds: “Good! That shows your heart is
working harder to pump blood round your body. Today, we will study the
heart, how blood circulates, and the problems of the circulatory system.”
Presentation
(30 minutes)
Step
1: Structure and Functions of the Heart (7 minutes)
- Teacher shows chart/model of the human heart.
- Explains that the heart is a muscular organ located in
the chest cavity, slightly to the left.
- Points out the four chambers:
- Right Atrium → receives deoxygenated blood from the
body
- Right Ventricle → pumps deoxygenated blood to the
lungs
- Left Atrium → receives oxygenated blood from the lungs
- Left Ventricle → pumps oxygenated blood to the body
- Functions of the heart:
1.
To pump blood round the body
2.
To ensure supply of oxygen and
nutrients to all tissues
Students’
Activity: Observe and identify chambers of
the heart on the chart.
Step
2: Circulation of Blood (8 minutes)
- Teacher explains that blood circulates in two major
ways:
- Pulmonary circulation – blood flows from the heart to the lungs and back
(for oxygenation).
- Systemic circulation – blood flows from the heart to the rest of the body
and back.
- Shows diagram and traces pathway:
o
Deoxygenated blood → right atrium →
right ventricle → lungs (oxygenated) → left atrium → left ventricle → body.
Arteries carry blood away from the
heart, veins carry blood to the heart, capillaries link the two.
Students’
Activity: Students follow blood pathway with
their fingers on the diagram.
Step
3: Application through Diagram (5 minutes)
- Teacher draws simplified diagram of blood circulation
on the board.
- Explains labeling (heart, lungs, arteries, veins,
body).
- Students’ Activity:
Students reproduce the diagram neatly in their notebooks and label it
correctly.
Step
4: Effects of Improper Circulation (5 minutes)
- Teacher explains that if circulation is blocked or
reduced:
- Organs do not get enough oxygen.
- Person feels weak, dizzy, or may collapse.
- Prolonged poor circulation can damage organs or cause
death.
- Students’ Activity:
Students share experiences of weakness, dizziness, or tiredness, and
relate to poor blood supply.
Step
5: Diseases of the Circulatory System (5 minutes)
- Teacher explains three diseases:
- Hypertension (High Blood Pressure): when blood pressure in vessels is too high.
- Heart Attack:
when blood supply to the heart muscle is blocked.
- Stroke:
when blood supply to the brain is cut off.
- Preventive measures:
o
Regular exercise
o
Eating balanced diet
o
Avoiding smoking and alcohol
o
Reducing stress
Students’
Activity: Students suggest other ways to keep
heart healthy.
Evaluation
(5 minutes)
Teacher asks students:
- Mention the four chambers of the heart.
- Explain the difference between pulmonary and systemic
circulation.
- Draw and label the pathway of blood in the body.
- What happens when blood circulation is interrupted?
- Mention two diseases of the circulatory system and
suggest preventive measures.
Assignment
- Draw and label the human heart neatly in your
notebooks.
- Write short notes on three diseases of the circulatory
system and state how they can be prevented.
References
- Basic Science for Junior Secondary Schools, Book 2
- Teacher’s Note/Charts
0 Comments