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13.2: Homeostasis

Difficulty Level: At Grade Created by: CK-12
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What happens if stability is disrupted?

Remove one stone and the whole arch collapses. The same is true for the human body. All the systems work together to maintain stability or homeostasis. Disrupt one system, and the whole body may be affected.

Homeostasis

All of the organs and organ systems of the human body work together like a well-oiled machine. This is because they are closely regulated by the nervous and endocrine systems. The nervous system controls virtually all body activities, and the endocrine system secretes hormones that regulate these activities. Functioning together, the organ systems supply body cells with all the substances they need and eliminate their wastes. They also keep temperature, pH, and other conditions at just the right levels to support life processes.

Maintaining Homeostasis

The process in which organ systems work to maintain a stable internal environment is called homeostasis . Keeping a stable internal environment requires constant adjustments. Here are just three of the many ways that human organ systems help the body maintain homeostasis:

• Respiratory system: A high concentration of carbon dioxide in the blood triggers faster breathing. The lungs exhale more frequently, which removes carbon dioxide from the body more quickly.
• Excretory system: A low level of water in the blood triggers retention of water by the kidneys. The kidneys produce more concentrated urine, so less water is lost from the body.
• Endocrine system: A high concentration of sugar in the blood triggers secretion of insulin by an endocrine gland called the pancreas. Insulin is a hormone that helps cells absorb sugar from the blood.

Failure of Homeostasis

Many homeostatic mechanisms such as these work continuously to maintain stable conditions in the human body. Sometimes, however, the mechanisms fail. When they do, cells may not get everything they need, or toxic wastes may accumulate in the body. If homeostasis is not restored, the imbalance may lead to disease or even death.

Summary

• All of the organ systems of the body work together to maintain homeostasis of the organism.
• If homeostasis fails, death or disease may result.

Practice

Use this resource to answer the questions that follow.

1. What is homeostasis?
2. Describe the reason for shivering.
3. What is negative feedback?
4. Why can homeostasis be compared to temperature regulation in a house?
5. Describe how organ systems work together to maintain homeostasis.

Review

1. What is homeostasis?

2. Describe how one of the human organ systems helps maintain homeostasis.

3. A house has several systems, such as the electrical system, plumbing system, and heating and cooling system. In what ways are the systems of a house similar to human body systems?

Vocabulary Language: English Spanish

endocrine system

endocrine system

Organ system of glands that release hormones into the blood.
nervous system

nervous system

Organ system that carries electrical messages throughout the body.

Feb 24, 2012

Oct 03, 2014