Unit:  Human Respiratory and Circulatory Systems

Essential Question:

How does what you eat affect your heart rate and your breathing?

Unit Description:

                This unit is the third unit of the year.  The first unit was about two weeks at the beginning of the year, and introduced students to the scientific method, the different types of scientists, and attempted to break the typical stereotype of  a scientist and show all students that they could be scientists.  The second unit was about a month and a half learning about the human digestive system.  The students were asked to learn about the structures and functions of the various parts of the system.  They learned what enzymes digested foods in various parts of the digestive system.  They also learned about diffusion across membranes.  They performed these tasks using a variety of readings, labs, investigations, diagrams, vocabulary, and models.  In the upcoming unit on the human respiratory and circulatory systems, the students will build upon their knowledge of scientific investigation and be asked to design their own experiment.  They will also build upon their knowledge of human body systems by tying concepts such as diffusion and the products of digestion into the respiratory and circulatory units.  This will be accomplished using similar methods as in the previous unit.

Learning Goals for Unit:



Students will use a variety of models to represent the human respiratory and circulatory systems

Students will created, draw, label, and describe strengths and weaknesses of models of the various parts of the respiratory system.

Students will be able to identify the structures and functions of the respiratory system

Students will be able to label diagrams of the respiratory system and describe the functions of those structures

Students will learn about human lung capacity

Students will be able to explain a lab where they measure the lung capacity of themselves and their classmates.

Students will learn what happens when fuel combines with oxygen

Student will be able to explain combustion, oxidation, and cellular respiration, and describe the similarities and differences between them, as well as the inputs and outputs of cellular respiration

Students will understand food energy.

Students will be able to define calorie, and describe how they are measured, and in what units, as well as comparing the energy release of different foods

Students will be able to explain the structure and function of the human heart

Studnets will be able to draw the flow of blood through the human body, label the structures of a heart, and describe their functions.

Students will design an inquiry into the human heart

Students will design and conduct an experiment determining factors that affect the human heart rate

Students will investigate the conditions that affect blood pressure

Students will be able to explain what conditions cause an increase or decrease in blood pressure



Applicable Standards:


6-8 SYSA

Any system may be thought of as containing subsystems and as being a subsystem of a larger system.

Given a system, identify subsystems and a larger encompassing system (e.g., the heart is a system made up of tissues and cells, and is part of the larger circulatory system).


6-8 SYSC

The output of one system can become the input of another system.

Give an example of how output of matter or energy from a system can become input for another system (e.g., household waste goes to a landfill).*a

6-8 INQA


Scientific inquiry involves asking and answering questions and comparing the answer with what scientists already know about the world.

Generate a question that can be answered through scientific investigation. This may involve refining or refocusing a broad and ill-defined question.


6-8 INQB


Different kinds of questions suggest different kinds of scientific investigations.

Plan and conduct a scientific investigation (e.g., field study, systematic observation, controlled experiment, model, or simulation) that is appropriate for the question being asked.


Propose a hypothesis, give a reason for the hypothesis, and explain how the planned investigation will test the hypothesis.


Work collaboratively with other students to carry out the investigations.

6-8 INQD


For an experiment to be valid, all (controlled) variables must be kept the same whenever possible, except for the manipulated (independent) variable being tested and the responding (dependent) variable being measured and recorded. If a variable cannot be controlled, it must be reported and accounted for.

Plan and conduct a controlled experiment to test a hypothesis about a relationship between two variables. *c Determine which variables should be kept the same (controlled), which (independent) variable should be systematically manipulated, and which responding (dependent) variable is to be measured and recorded. Report any variables not controlled and explain how they might affect results.


6-8 INQE


Models are used to represent objects, events, systems, and processes. Models can be used to test hypotheses and better understand phenomena, but they have limitations.

Create a model or simulation to represent the behavior of objects, events, systems, or processes. Use the model to explore the relationship between two variables and point out how the model or simulation is similar to or different from the actual phenomenon.


6-8 LS1A

All organisms are composed of cells, which carry on the many functions needed to sustain life.

Describe the functions performed by cells to sustain a living organism (e.g., division to produce more cells, taking in nutrients, releasing waste, using energy to do work, and producing materials the organism needs).

6-8 LS1C

Multicellular organisms have specialized cells that perform different functions. These cells join together to form tissues that give organs their structure and enable the organs to perform specialized functions within organ systems.

Relate the structure of a specialized cell (e.g., nerve and muscle cells) to the function that the cell performs.


Explain the relationship between tissues that make up individual organs and the functions the organ performs (e.g., valves in the heart control blood flow, air sacs in the lungs maximize surface area for transfer of gases).


Describe the components and functions of the digestive, circulatory, and respiratory systems in humans and how these systems interact.


This Lesson Set:

                The lessons shown in this unit plan are the first few lessons in the unit.  These lessons will gather information about student preconceptions surrounding the human respiratory system, and then begin with an activity where the students construct a model of how human lungs work.  The students will then be involved in a set of lessons which lead the students in investigating how much air a human can hold in their lungs, and then learn about the process of combustion and cellular respiration, and how the students use the oxygen they are getting from breathing.  Following the lessons in the plan will be a set of lessons moving into the circulatory system.  Students will complete a lab activity where they learn about how calories are measure, how much energy is in a variety of foods, and have a brief overview of the food pyramid.  In the next lesson, Students will learn about the double-pump action of the heart using another model, determine the flow of blood through the heart, and study the structures of the human heart.  At this point, the students will learn about how the food that they eat and the calories that they get are used in cellular respiration, and the oxygen they learned about during the respiration section are carried through the blood stream by the heart.  In the next lesson, students will design an inquiry that explores what factors may affect the heart rate, and perform a reading about the importance of blood.  Following this lesson, the students will use another model to explore how the diameter of a tube affects how hard a pump must work, and then relate this to the structure and functions of the heart, as well as blood circulation that they learned about in the previous units.  Following will be a unit exam testing whether the learning objectives were met.

This is a unit that I implemented in collaboration with my Cooperating Teacher during my Student Teaching Internship.  Many of these lessons and activities are based around activities that had been used in the past, along with some modifications and new ideas.  This is a unit that was created following a set district curriculum based on a Human Body text selected by the district.

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