Levels of Structural Organization

Levels of Structural Organization - for the body At the...

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Levels of Structural Organization From Atoms to Organisms The human body exhibits many levels of structural complexity (Figure 1.1). The simplest level of the structural ladder is the chemical level, which we will study in Chapter 2. At this level, atoms, tiny building blocks of matter, combine to form molecules such as water, sugar, and proteins. Molecules, in turn, associate in specific ways to form microscopic cells, the smallest units of all living things. The cellular level is examined in Chapter 3. Individual cells vary widely in size and shape, reflecting their particular functions in the body. The simplest living creatures are composed of single cells, but in complex organisms like human beings, the structural ladder continues on to the tissue level . Tissues consist of groups of similar cells that have a common function. As we will discuss in Chapter 3, each of the four basic tissue types plays a definite but different role in the body. An organ is a structure, composed of two or more tissue types, that performs a specific function
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Unformatted text preview: for the body. At the organ level of organization, extremely complex functions become possible. For example, the small intestine, which digests and absorbs food, is composed of all four tissue types. All the body’s organs are grouped so that a number of organ systems are formed. An organ system is a group of organs that cooperate to accomplish a common purpose. For example, the digestive system includes the esophagus, the stomach, and the small and large intestines (to name a few of its organs). Each organ has its own job to do, and working together, they keep food moving through the digestive system so that it is properly broken down and absorbed into the blood, providing fuel for all the body’s cells. In all, 11 organ systems make up the living body, or the organism, which represents the highest level of structural organization, the organismal level . The major organs of each of the systems....
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This note was uploaded on 11/08/2011 for the course BIOLOGY BSC1086L taught by Professor Leostouder during the Fall '10 term at Broward College.

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