Human Physiology

Sample Lesson - Introduction

Lesson 1.01: Respiratory System

Breathe in, breathe out. Breathe in, breathe out. It gets harder when you start thinking about it, right? Thankfully, your respiratory system has got it completely under control, with very little input from you at all. As you're reading this, it's plugging away. As you're exercising, it's working even harder. Certainly it takes a break while you're sleeping, right? Nope, it's still working. The respiratory system never gets a vacation. (When it does, we call it fainting, and it tends to be so short it's not worth using the vacation days anyways.)

Despite being such a hard worker, we usually don't give the respiratory system any credit. Do you think about every breath you take? The Police do, but we're guessing you hadn't thought about one since that first paragraph.

The respiratory system consists of the organs responsible for helping us breathe. These organs include the nose, mouth, throat (pharynx), larynx, trachea, bronchi, and lungs. We breathe in through our mouths or nose, and it passes through the pharynx, larynx, and trachea. The trachea splits into two bronchial tubes that lead into our famous air storage units, the lungs. The lungs, with the help of blood vessels, deliver the oxygen to the body and get rid of the waste products, including carbon dioxide. Then they do it again, and again, as long as you both shall live.

Behold the lungs, the hardest working balloons we know of.
(Source)

The whole process happens so quickly we wouldn't even have time to think about each step between breaths, but in this lesson, we'll have the opportunity to cover each step in depth, as well as read about the organs that compose the system and their functions.

We often learn the most about physiology by studying what happens when things go wrong or don't work as they should. To this end, our activity will involve choosing a respiratory disease and learning about the causes and treatment of that condition. You'll come out with an appreciation of our hardy ventilation systems that you never had before.

Take one more breath (and make it a good one) because it's time to get started.

Sample Lesson - Reading

Reading 1.1.01: The Respiratory System

It's off to the National Heart, Lung, and Blood Institute to learn more. We're taking a quick, digital fieldtrip. (For once, there's no need to bring lunch money.) Check out this page to read all about the respiratory system.

Under "Explore How the Lungs Work" on the left of the page, read the following sections:

• The Respiratory System
• What Happens When You Breathe
• What Controls Your Breathing
• Lung Diseases and Conditions

While you take notes, you may find it helpful to draw a diagram that illustrates the flow of oxygen in and carbon dioxide out using that little animation in What Happens When You Breathe. Make sure to note the differences between a breath in and a breath out. There are more changes than just the direction of the little air arrow.

Also take a quick look at Shmoop's guide to respiration, but especially read what's under the Mammals heading. It goes into more depth about how gas exchange works and what tidal volume means, both of which are important for understanding the whole process.

Who knew there was so much going on in there? After doing it since the second we were born, we were under the false impression that we were breathing experts.

Sample Lesson - Activity

Activity 1.01a: Respiratory Diseases

Fortunately for most of us, our respiratory system works well. So well, in fact, that we usually don't even notice that it's hard at work. (Until we get the hiccups in a very echo-y auditorium.) That's not the case for many people. Diseases of the respiratory system that can have a large impact of a person's quality of life.

In this activity, you will pick a disease of the respiratory system and write a one to two page double-spaced report about it. You can pick a disease mentioned in the Lung Diseases and Conditions of your reading, or anything appearing on this list.

Your paper should include the following:

• Background on the respiratory system
• What causes the disease
• Exactly how the disease affects the respiratory system
• Any treatments or ways to prevent the disease
• Photos and/or diagrams are always good. We like pictures.
• A Works Cited referencing the resources you used

After you've finished, submit your paper below, and breathe a sigh of relief if you get it in on time. (Just to clarify, a sigh of relief works just like every other kind of breath. Now that you know all the crucial steps and parts, this sigh of relief should be particularly satisfying.)

Sample Lesson - Activity