Term
| Describe the topics covered in human physiology: |
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Definition
| It is the study of biological function-from cell to tissue, tissue to organ, organ to system and how the organism as a whole accomplishes tasks essential for life. |
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Term
| What sequences are emphasized in the study of physiology? |
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Definition
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Term
| How is knowledge of physiological mechanisms obtained? |
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Definition
| From data observed experimentally. |
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Term
| What other sciences do physiology overlap? |
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Definition
| Chemistry, physics, pathophysiology (function of diseased or injured body systems) and comparative physiology (physiology of animals) |
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Term
| Describe the 3 characteristics of the scientific method: |
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Definition
1- assumption that the subject under study can be explained in terms we can understand 2- descriptions and explanations are honestly based on observations of the natural world, and can be changed by new observations 3- Humility. The scientist must be willing to change theories based on the weight of the evidence. |
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Term
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Definition
| The state of "dynamic constancy" of the internal environment depite changing conditions of the external environment. Maintained by negative feedback loops. |
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Term
| Identify the components of negative feedback loops: |
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Definition
1) A sensor-detecting change in the internal environment 2) Integrating center-determines response 3) An effector- that can be activated by the sensor |
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Term
| What is negative feedback? |
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Definition
| When the body's sensor detects a deviation from the set point and stimulates an effector to bring the deviation back to the set point. Since it is always in a negative or reverse direction back to the set point it is called "negative" feedback. |
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Term
| Explain the role of antagonistic effectors in maintaining homeostasis: |
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Definition
| The increasing activity of one effector is accompanied by the decreasing activity of an antagonistic effector, and vice versa. This allows for a finer degree of control than if an effector was just shut on and off (tonic control). ex. sweating and shivering bring temperature back to set point |
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Term
| Describe the nature of positive feedback loops: |
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Definition
| Instead of antagonistic control, the action of effectors amplifies the changes that stimulated the effectors. ex. a thermostat that increases heat production in response to a rise in temperature; uterine contractions during childbirth: fetus feels stress and releases oxytocin which stimulates uterine contraction, which creates more stress ect. |
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Term
| Give an example of how negative feedback loops involving the endocrine system helps to maintain homeostasis after eating: |
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Definition
Eating->raises blood glucose->pancreatic islets (of Langerhans) act as sensor, integrating center and effector; detect increased blood glucose ->stimulation of pancreatic islets increase insulin ->increased cellular uptake of glucose->decreased blood glucose |
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Term
| Give an example of how a negative feedback loop involving the endocrine system can help to maintain homeostasis after fasting: |
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Definition
Fasting->lowers blood glucose->pancreatic islets(of Langerhans) act as sensor, integrating center and effector; detect decreased blood glucose-> stimulation of pancreatic islets decrease insulin-> triggers glucagon production->decreased cellular uptake of glucose->liver secretes glucose ->increased blood glucose |
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Term
Give an example of how negative feedback loops involving the nervous system help to maintain homeostasis: |
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Definition
| Lying down to standing up position->blood pressure falls=stimulus->baroreceptors (blood pressure receptors)stimulated=sensor->stimulates sensory nerve fibers->medulla oblongata=integrating center->motor nerve fibers->heart=effector->heart rate increases->blood pressure rises=response |
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Term
| A resonse loop always begins with a ___ and always ends with a ____: |
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Definition
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Term
| What is the purpose of the scientific method? |
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Definition
| To give us reliable, dependable information. |
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Term
| What is a response loop composed of? |
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Definition
1)stimulus 2)sensor/receptor 3)afferent pathway 4)integrating center w/ set point 5)efferent pathway 6)effector 7)response |
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Term
| What is intrinsic control? |
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Definition
| Control is built into organ being regulated |
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Term
| What is extrinsic control? |
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Definition
| Control comes from outside of organ being regulated |
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Term
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Definition
| When some metabolism of a cell only affects a small number of surrounding cells. |
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Term
| Which effectors of the baroreceptor reflex are under antagonistic control? |
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Definition
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Term
| Which effectors of the baroreceptor reflex are under tonic control? |
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Definition
| Arterial smooth muscle and ventricular myocardium |
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