CK12 Life Science

Figure 16.24: The components of muscle contraction. The sacromereis the functional unit of muscle contraction; it reaches from o ...

Figure 16.25: When each end of the myosin thick filament moves along the actin filament, the two actin filaments at opposite sid ...

Figure 16.26: The process of actin and myosin sliding past one another is called crossbridge cycling, and it occurs in all muscl ...

Anaerobic Exercise and Muscular Strength Anaerobic exercisescause muscles to get bigger and stronger. Anaerobic exercises use a ...

Figure 16.28: When done regularly, aerobic activities such as cycling, make the heart stronger. ( 26 ) diseases such as cardiova ...

Muscle Injuries Sometimes muscles and tendons get injured when a person starts doing an activity before they have warmed up prop ...

normally do. For example, if you run, you can rest your running muscles and joints by swimming. This type of rest is calledactiv ...

Why is warming up before exercise a good idea? Why are taking anabolic steroids a dangerous way to try to build up muscles? Fu ...

muscular strength The ability of a muscle to exert force during a contraction. muscular system The body system that allows movem ...

Image Sources (1) http://commons.wikimedia.org/wiki/File:Illu_vertebral_column.jpg. Public Domain. (2) CK-12 Foundation. http:// ...

(15) CK-12 Foundation. http://en.wikipedia.org/wiki/Image:Glanzstreifen.jpg http://commons.wikimedia.org/wiki/Image: Skeletalmus ...

(27) CK-12 Foundation. http://commons.wikimedia.org/wiki/File:Heart_myocardium_diagram.jpg. CC-BY 2.5. (28) CK-12 Foundation. ht ...

Chapter 17 Food and the Digestive System 17.1 Lesson 17.1: Food and Nutrients Lesson Objectives Explain why the body needs food ...

Figure 17.1: This girl is eating a salad of tomatoes and leafy green vegetables. Fresh veg- etables such as these are excellent ...

Carbohydrates Carbohydratesare nutrients that include sugars, starches, and fiber. How many grams of carbohydrates you need each ...

Starches are large, complex carbohydrates. They are found in foods such as vegetables and grains. Starches are broken down by th ...

Figure 17.3: Between the ages of 9 and 13 years, girls need about 26 grams of fiber a day, and boys need about 31 grams of fiber ...

Figure 17.4: Between the ages of 9 and 13 years, you need about 34 grams of proteins a day. What other foods do you think are go ...

Lipids Lipidsare nutrients such as fats that store energy. The heart and skeletal muscles rely mainly on lipids for energy. One ...

Vitamins Vitaminsare substances that the body needs in small amounts to function properly. Hu- mans need 13 different vitamins. ...