Innate Immune System
[Figure 1] How does your body keep most enemies out? Many would consider the moat around this castle, together with the thick stone castle walls, as the first line of defense. Their role is to keep the enemy out, and protect what’s inside. The First Line of Defense [Figure 2] Does this organism look like a space […]
Excretory System Diseases
[Figure 1] How do you block the flow of urine? Kidney stones. Imagine having that travel through your excretory system. OK, that’s not a kidney stone, but you get the idea. Kidney stones can be more than a few millimeters in diameter. Painful? Sometimes extremely uncomfortable. And how does a stone leave the kidney? The same way urine does. […]
Kidneys
Why is a bean-shaped organ so important? Shown above are the isolated kidneys from many little mice. OK, they’re really just kidney beans. But this is what the important kidney looks like. Why is it so important? Your kidneys filter and remove wastes from your blood. The Kidneys The kidneys are a pair of bean-shaped organs just above […]
Urinary System
[Figure 1] How is it determined what’s waste and what’s not? Getting rid of waste and excess water is a major process of maintaining homeostasis. Such a basic process is actually very complex. It involves an intricate exchange of material through the kidney. Urinary System The kidneys are part of the urinary system, which is shown in Figure below. The main function of the […]
Excretory System
What do you do with your waste? Toxic waste must be disposed of properly or there can be serious consequences. Your waste needs to be removed from you. And that is the role of the excretory system. The excretory system gets rid of waste and excess water. Excretion If you exercise on a hot day, you are likely […]
Balanced Eating
[Figure 1] Why is the good stuff in the smallest segment of this diagram? If you’re like most high school kids, one of the first things you do after school is search for something to eat. And you look for the chips or candy. As this diagram shows, you can eat those. Just not a lot. Balanced […]
Food and Nutrients
[Figure 1] Are these really good for you? Fresh fruit and vegetables. Every child’s favorite. Especially those vegetables. When your mother tells you to “eat your vegetables,” there is a reason for that. Yes, they are actually good for you. Food and Nutrients Did you ever hear the saying, “You are what you eat”? It’s not just […]
Digestive System Diseases
[Figure 1] What’s worse than an upset stomach? You’ve probably had an upset stomach. Most likely it was due to something you ate. But imagine bleeding from your stomach. That’s a little different than your stomach just being upset. Stomach ulcers can be very serious. Diseases of the Digestive System Many diseases can affect the digestive system. Three of […]
Large Intestine
[Figure 1] Liquid to solid. What does this mean? Well, that’s exactly what the large intestine does. It takes the remains of digested food — that is, food in which all the nutrients and minerals have been removed, and prepares it for elimination. The Large Intestine and Its Functions From the small intestine, any remaining food wastes pass into the large intestine. The large […]
Small Intestine
[Figure 1] These projections absorb. Absorb what? Imagine the inside walls of the 23 feet of your small intestine covered with these finger-like projections. Why? What’s their purpose, and why is the small intestine so long? These projections absorb. Absorb what? Minerals and nutrients from food. And the length of the small intestine allows as much of these important substances […]
