Example

Dress Rehearsal

In applying the concepts about nutrition and metabolism, your anatomy book takes a look at the impact of proper nutrition on the performance of an athlete. Great! You currently dominate your division’s 200-meter race, leaving your competitors in the dust… er, rubber. Constantly striving to improve your time, you’ll be analyzing the text’s explanation with enthusiasm.

Your teacher has posed this question: Can what an athlete eats help her win? Your text answers, Yes. But before you hand over your Doritos, you want some proof. What evidence does the text provide in arriving at this conclusion? Let’s take a look.

First, the text explains that carbohydrates are “the athlete’s best friend.” To support this idea, the text points out distinctions, especially misconceptions, about protein. Many of us believe that athletes need a lot more protein than the rest of us. Your text, however, shows that while an athlete needs a little more protein than the average couch potato, the difference isn’t that great. Athletes need about 1 gram of protein per kilogram of their weight per day compared to 0.8 for the non-athlete.

Too much protein is a strain on the kidneys while too little causes declining hemoglobin levels. Both of these conditions would certainly have a negative effect on athletic performance. Worth noting, right?

So what should an athlete concentrate on? Getting more carbohydrates through vegetables and grains. These carbohydrates are not full of fat, as meats tend to be. They provide a much-needed energy source, but in a healthier way. A good meal to have two to five hours before a demanding event is one that consists of 500 to 1,500 calories. It should be high in carbohydrates in order to provide the necessary energy while being easy to digest. Remember that for your next meet, Track Star.

Feeling tired before, during, and after a track meet? You probably need more hydration. An athlete can lose up to two to four quarts of water per hour. And, your text advises, water should be your drink of choice. Avoid the use of sugary drinks which can create havoc in your digestive system. Some of them even contain alcohol which can cause further dehydration. Certainly not what the Olympic gods intended.

What about the idea that athletes need to take vitamin and mineral supplements? The authors agree that a well-balanced diet provides enough nutrients to support healthy functioning. Sodium tablets are often taken by athletes suffering cramps, but just adding salt to your food should be enough. Potassium levels are very important, too. Proper levels can be maintained by eating bananas. Dried dates, apricots, and raisins are handy on meet days. Resist those potato chips. That’s NOT what we mean when we say salt your food.

Your text also warns about the use of the dietary supplement, creatine. It points out that cells can produce their own creatine, so taking too much of this in the form of supplements can cause the muscles to deteriorate rather than build up. Many adverse effects of creatine supplements have been recorded, including muscle cramps, diarrhea, muscle strains, and dehydration. You wouldn’t want to be on the track when any of THOSE things happen. Wardrobe malfunction. Death has even occurred for some overzealous athletes.

In answering the question about athletes and nutrition, your text has provided useful information about your food regimen. It has corrected many false impressions that many of us have about proteins. You now know that those sugary drinks aren’t what you need and that supplements can be dangerous. You notice that the text does not explain how many professional athletes advantageously and safely use creatine supplements, but chances are, they’re under the careful watch of qualified physicians and trainers.

Now you’re ready to form your own interpretations of how important diet is to athletic performance. You’ll need to use evidence from the text to support your ideas, but be sure to also note the information that this text leaves out and what those gaps might mean for this issue.

Source:

Shier, David, et al. Human Anatomy & Physiology, 10th edition. New York: McGraw-Hill, 1996.

Drill

Read the following passage. Answer the questions, using direct quotations from the text.

The lymph system is a network of organs, lymph nodes, lymph ducts, and lymph vessels that produce and transport lymph from tissues to the bloodstream. The lymph system is a major component of the body's immune system.

Lymph is a clear-to-white fluid made of:

• fluid from the intestines called chyle, which contains proteins and fats.
• white blood cells, especially lymphocytes, the cells that attack bacteria in the blood.

Lymph nodes are small, bean-shaped, soft nodules. They cannot usually be seen or easily felt. They are located in clusters in various parts of the body, such as the neck, armpit, groin, and inside the center of the chest and abdomen.

Lymph nodes produce immune cells that help the body fight infection. They also filter the lymph fluid and remove foreign material such as bacteria and cancer cells. When bacteria are recognized in the lymph fluid, the lymph nodes produce more infection-fighting white blood cells, which causes the nodes to swell.

The lymphatic system includes the tonsils, adenoids, spleen, and thymus.

Source:
“Lymph System.” ADAM Health Illustrated Encyclopedia. 13 April 2009. Healthline. 5 May 2012. http://www.ask.com/health/adamcontent/lymph-system.

QUESTIONS:

1. Define lymph node.
2. Describe a lymph and lymph node.
3. Where can lymph nodes be found in the body?
4. Explain how a lymph node functions.
5. Name four body parts that are included in the lymphatic system.

ANSWERS:

1. “The lymph system is a network of organs, lymph nodes, lymph ducts, and lymph vessels that produce and transport lymph from tissues to the bloodstream.”

2. “Lymph is a clear-to-white fluid made of fluid from the intestines called chyle and white blood cells, especially lymphocytes. Lymph nodes are small, bean-shaped, soft nodules.”

3. “They are located in clusters in various parts of the body, such as the neck, armpit, groin, and inside the center of the chest and abdomen.”

4. “Lymph nodes produce immune cells that help the body fight infection. They also filter the lymph fluid and remove foreign material such as bacteria and cancer cells.”

5. “The lymphatic system includes the tonsils, adenoids, spleen, and thymus.”