The lesson focuses on understanding the main functions of the human body's muscular, skeletal, digestive, circulatory, and respiratory systems. It explores how these systems work in tandem, such as delivering oxygen and nutrients, facilitating movement, and supporting overall bodily functions. Additionally, there is an activity involving a model to visually demonstrate muscle and bone movement.

1. HUMAN BODY SYSTEM
QUARTER 2 – LESSON 1

2. OBJECTIVES
At the end of the lesson, you should be able to:
1. Identify the main functions of the following
body systems: muscular, skeletal, digestive,
circulatory, and respiratory; and
2. Describe how the different body systems work
together to make the body function well.

3. CIRCULATORY
SYSTEM
The major function is to ensure
that oxygen, the vital substance in
the body, is being transported
from the blood to the heart and
other systems’ organs including
the brain, the liver, and the
stomach. Its major organs are the
heart, arteries, veins, and blood.

4. DIGESTIVE SYSTEM
It processes the energy that is derived from the
materials that are distributed throughout the
body.
It processes and breaks down the food passing
through the mouth, the esophagus, the
stomach, and the small and large intestines.
The digestive process is called metabolism, a
chemical reaction that helps breakdown food
into nutrients such as carbohydrates, fats, and
proteins.

5. MUSCULAR SYSTEM
This system is responsible for generating
movements using the different body
muscles attached to the bones and blood
vessels.
Three main functions are mobility, stability,
and posture.
The movement of each muscle is
determined by the direction it receives from
the different areas of the body.

6. RESPIRATORY SYSTEM
The main role is to move oxygen to the
body tissues and remove carbon dioxide
from the body.
It controls and regulates the breathing
process that includes the movement of
air in and out of the lungs.
Primary organs: the nose, the
pharynx(throat), the larynx (voice box),
the trachea (windpipe), the bronchi, the
alveoli, and the lungs.

7. SKELETAL SYSTEM
It gives the distinctive shape of the human body.
It also acts as a lever that generally works with the
muscles attached to the bones.
It provides the power and strength to accomplish a
certain task.
It supports the circulatory and immune systems by
manufacturing red and white blood cells.
It facilitates movements and protects the internal
organs of the body.
Main parts: the bones, cartilage, ligaments, and
tendons

8. Some body organ systems that
work together:
BODY ORGAN SYSTEM TASKS BEING ACCOMPLISHED
CIRCULATORY AND RESPIRATORY
SYSTEMS
Deliver oxygen to cells and get rid
of the carbon dioxide that the cells
produce.
MUSCULAR AND SKELETAL
SYSTEMS
Support and give shapes to the
body and help create movements
DIGESTIVE AND CIRCULATORY
SYSTEMS
Provide the needed nutrients for
the heart to keep on beating
CIRCULATORY, RESPIRATORY,
SKELETAL, AND MUSCULAR
SYSTEMS
Function together when the body
does some exercise.

9. ACTIVITY 1
BALLOON MUSCLES AND BONES
Problem: What will happen to your arm muscles
as they move?
Materials: two pieces 2” x 6” cardboard strips,
one red balloon, two plastic fasteners, one blue
balloon, tape, and a puncher.

10. Observations and results
Parts of the
Model
Parts of the body
it represents
Balloons
Plastic fastener
Paper strips