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17 Cards in this Set
- Front
- Back
What is the
central principle of physiology? |
The normal function
of physiological systems is to maintain fairly constant internal conditions. |
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Define homeostasis.
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A stable internal environment.
|
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Define homeostatic regulation.
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Adjustments in physiological systems
that are responsible for preserving homeostasis/a stable internal environment. |
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List some vital characteristics that must be maintained within relatively narrow limits required for body function.
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The mechanisms
responsible for controlling levels of: -oxygen -carbon dioxide -glucose -pH -blood pressure, etc. |
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The two general mechanisms
involved in homeostatic regulation. |
-Autoregulation
-Extrinsic regulation |
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Define Autoregulation.
|
General mechanism involved in homeostatic regulation when the activities of the cell, tissue, organ,
or system change automatically when there is some change in its environment. |
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Example of Autoregulation.
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When cells within a tissue need more
oxygen, they release chemicals that cause an increase in blood flow to the area, providing more oxygen to the region. |
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Define Extrinsic Regulation.
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Homeostatic regulation which
results from the activities of the nervous or endocrine system, organ systems that can control or adjust the activities of many different systems simultaneously. |
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Examples of Extrinsic Regulation.
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-When you are exercising, your NS
issues commands that increase the HR so that blood will circulate faster. -NS reduces blood flow to organs, such as the digestive tract, that are relatively inactive (oxygen in circulating blood thus saved for the active muscles.) |
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What kind of responses do the
Nervous System and Endocrine System regulate? Differentiate. |
-The NS directs rapid, ST, and very
specific responses. -The Endocrine System releases hormones (responses not immediately apparent, but when effects appear, they often persist for days or weeks. |
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Define Hormones.
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Chemical messengers.
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Example of Endocrine Regulation
or Function |
-Regulation of blood volume and
composition. -Adjustments of organ system function during starvation or stress. |
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What are the factors involved
in Regulatory Mechanisms? |
-Receptor (sensor sensitive to that
particular stimulus) -Effector (that which engages in activity which has an effect on the same stimulus.) -Control/Integration Center (between receptor and effector - receives information from receptor and controls effector) |
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Define Set Point.
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Optimal level for the
controlled condition. |
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Negative Feedback
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Homeostatic regulation mechanism
where an effector activated by the control center acts to eliminate the stimulus or reduce its magnitude. |
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Give an example of Negative Feedback.
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Thermoregulation
|
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Define Thermoregulation.
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Mechanism involving the altering of the
relationship between heat loss, which occurs primarily on the body surface, and heat production, which occurs in all active tissues. |