Human Body Organization Levels

The human body has several levels of structural organization. These structural levels increase in complexity as they ascend from the smallest level to the largest level. This paper briefly identifies and expounds on the human body organization levels from the smallest to the largest.

            The Chemical level, also known as the molecular level, is the smallest structural level in the human body (Marieb 4). The chemical level is composed of atoms which form the smallest building blocks of matter.Atoms combine to form molecules, which in turn combine to form organelles that make up the internal composition of a cell.

            The Cellular level is made up of the cell, which is the smallest functional unit of a living organism (Thibodeau 1). Human beings are multi-cellular organisms with specialized independent cells that work together to perform specific tasks. Cells work together with similar cells to form the Tissue level.

            The Tissue level is composed of many similar cells that work collaboratively to perform a specific task. A tissue must have at least two different kinds of cells. Humans have four basic types of tissues: nervous, muscle, connective, and epithelium tissue (Anatomyandphysiologyi.com, 2018). The epithelial tissue forms the lining of most internal cavities and covers the surface of the body. Connective tissues, which is the most abundant and widely distributed tissue, supports cohesion and internal support and maintains the form and structure of the body. Examples of connective tissue include bones and blood. The nervous tissue makes up the nervous system and is responsible for communication and integration between all body parts. Muscle tissue is composed of muscle cells fibers responsible for contraction in all body parts.

            Organ level is made up of at two or more different types of tissues organized to perform certain tasks within the body (Marieb 5). The small intestines are a great example of how different tissues work together and make up an organ. The inside layer of the intestines is composed of epithelial cells that secrete digestive enzymes and others that are responsible for nutrients absorption. The intestines also have connective tissue layer and muscle tissues that contract to allow movement of food. The collaborative work of these tissues allows the small intestine to perform food absorption as an organ. Other Examples of organs include the skin, lungs, and heart.

 Organ System Level is made up of one or more organs that work in unison to perform a specific task. An example of an organ system is the digestive system, which is made up of various organs such as the mouth, esophagus,pancrease, liver, stomach, small intestines and large intestines. All these organs perform specific tasks but together are responsible for food digestion, absorption and excretion hence form the digestive system.

            Organismal Level is the most complex within the organization levels hierarchy. It is made up of all the other levels working together to accomplish all physiological functions hence forming a human being. Examples of these physiological functions include ingestion, growth, excretion, reproduction, and response to stimuli and the surrounding environment.

            The human body has six primary levels of structural organization. The complexity of these level increases as they move from the lowest level to the highest. All these levels combined and functioning together form the human body.

Works Cited

“A&P Levels of structural organization: Anatomy & Physiology.”anatomyadphysiology.com         www. anatomyandphysiologyi.com/ap-levels-of-structural-organization/                  Accessed 22 Dec. 2018

Marieb, E. Essentials of Human Anatomy & Physiology, 5th Edition.                                   Harlow, United Kingdom: Pearson Education Limited. 2001

Thibodeau, Gary. Structure and function of the body. Times Mirror/Mosby College pub            St.Louis, 1988