Student Portal:

The Human Body

Investigation 1 – PreLab









The human body is organized into systems that are made up of many parts and that these systems each perform both individual and complementary functions that occur at the same time in the body.


Physicians help people take care of their bodies. They find ways to make the body work better and to treat it when it gets sick. 



This Investigation is designed to:

  • introduce the body as a whole unit made up of systems that are comprised of smaller parts
  • promote understanding of systems as a group of related parts which work together for a common function
  • encourage explorations of the function of the nervous system
  • identify the three main parts of the nervous system: the brain, the spinal cord, and the nerves. 



  1. Brain: The organ that controls the body
  2. Function: The role or job of an object or part of an object. 
  3. Nerve:  A thin thread-like structure that carries signals between the brain, spinal cord, and parts of the body.
  4. Nervous system:  The system that controls and communicates with the parts of the body.
  5. Organ:  One of the parts of the body which make up a system.  The brain, the heart, and the stomach are examples of organs.
  6. Spinal cord:  The bundle of nerves that runs up and down the center of the back.  The spinal cord connects the brain to most of the nerves of the body.  The spinal cord carries signals between the brain and the parts of the body.  However, there are some nerves that directly connect the brain to the body.
  7. System:  A group of objects or parts that work together.


  • Tell students that they are about to begin The Human Body CELL. 
  • Ask students to share the kinds of things they might learn in these Investigations. 
  • Tell students they will think about the body, its parts, and how it functions. 

Begin the PreLab Concept Slides to start students on their learning journey. Then watch the Pre-Lab Student Video as a class. 





In this Investigation, we begin our study of the human body by focusing on one of the body’s systems, the nervous system.



What do you think the word function means? We can think of a function as the role or job of an object or part of an object. 

Below are some parts of the human body and their functions:

Eyes – functions in seeing

Ears – functions in hearing

Nose – functions in smelling

Skin – functions to protect the body, touching and feeling

Tongue – functions in tasteing and helping to chew

Brain – controls the body



Learning about the human body involves learning about all of the different parts of the body. 

The human body is made up of smaller parts just like a school is made up of small parts. If you look around you in your school, what do you see? You may see pencils, books, desks, chairs, students, teachers, and so on. 

In turn, these smaller parts make up a larger part, a classroom for example.

On the other hand, our classroom is just one of many other classrooms that make up a larger part – the whole school.



Just as a school is made up of different classrooms, the body is made up of different systems. A system is a group of objects or parts that work together. 

There are many similarities between a school/classroom and the body and its systems. Body systems are similar to classrooms. For example, classrooms have students, teachers, desks, and so on. They work together so each classroom can perform its own function. 

Each body system is also made up of parts. The parts work together so each body system can perform its function. 

Six body systems we will investigate in this CELL are:

  • Circulatory System 
  • Respiratory System
  • Digestive System
  • Nervous System
  • Skeletal System
  • Muscular System



In Investigation 1 we will learn about the nervous system. The brain sends messages in the form of electrical signals through nerves to all of the parts of the body. You should label these areas in your Student Data Record. 



We will create a model to show the path of a nerve impulse (signal) from the brain to the parts of the body. Imagine that you are walking and you accidentally run your foot into a desk and stub your toe. 

How do you know that you ran into a desk?

Sensations of pain are messages sent to the brain from the nerves in the foot.

In class, you will create the model. One student volunteer will be the brain and stand at the head of the classroom.  The brain is connected to the spinal cord. In the model, several students will stand next to each other to represent the spinal cord. These students will line up in front of the student representing the brain. 

Next, you will create nerves or pathways for signals to travel. Students representing nerves will line up at the end of the spinal cord opposite the student representing the brain. These students represent nerves to the foot. 

Finally, one student will represent the toe and another student the signal that passes from the foot to the brain. 



To begin the signal to the brain, the student representing “the signal” should pass along the nerves to the foot and the spinal cord until it reaches the brain. As the “signal” passes each student, he/she gives a “high-five” to model the passing of the signal. 

When the signal reaches the brain, the brain says, “Bump. Move around it!”



Now that the “brain” has perceived the stub on the toe and says, “Bump. Move around it!”, the signal must relay this information back to the toe. In the process, the student “signal” gives “high fives” as he/she moves from the brain, through the spinal cord, through the nerves in the foot, and to the toe. 

At the toe, the signal says, “Ouch. Move around it! 

The student who is the toe should then move to the side. 

Through this model, you should conclude that all nerves lead to the spinal cord rather than directly to the brain. 



What is the function of the nervous system? In the lab for Investigation 1, you will investigate this question. Think about this before watching the PreLab Student Video.




Watch the following Student Video in preparation for the lab.