Homeostasis Flashcards
The tendency of a living body to maintain relatively stable internal conditions in spite of greater changes in its external environment is known as ______.
Homeostasis
What is the term used for body conditions, such as temperature and blood pressure, that must remain within a narrow range and also can change?
Variable
An individual is suffering from a fever of 102 degrees Fahrenheit. Ideal body temperature is 98.6 degrees Fahrenheit. The set point for body temperature is _____ degrees Fahrenheit
98.6
Bodily changes are detected and responses are activated that reverse the change and restore stability and preserve normal body function during ______.
Negative feedback
The organ that carries out a response that changes the value of the variable is called a(n) ______.
Effector
Homeostasis is the body’s ability to maintain _____.
A relatively stable internal condition
Identify the function of the control center within a feedback mechanism.
Receives and processes information
Which of the following is/are characteristics of variables with regard to homeostasis?
1) They must remain within a narrow change.
2) Their values can change.
Baroreceptors in the aorta detect an increase in blood pressure. Nerves send information to the brain. The brain compares the value of the blood pressure to a set point. Nerves send information to the heart. The heart beats slower. Blood pressure decreases. In this example the effector is the ______.
Heart
In reference to living organisms, the set point can be defined as the _______.
ideal normal value of a condition such as blood pressure
A structure, molecule or cell that detects a stimulus (or change in body variable) is called a(n)
Receptor
Negative feedback is a mechanism that ______.
Reverses the change and maintains homeostasis
If the body temperature rises, sweat glands produce sweat and the body cools. This is an example of ______ feedback.
Negative
What portion of a feedback mechanism carries out a response to change a body variable?
Effector
True or false: A deviation from a set point always results in disease.
False
Sometimes these deviations are beneficial, such as the changes in heart rate and blood pressure seen with exercise
The part of the feedback mechanism that receives and processes information, relates it to other information, and makes a decision of action to be carried out by the effector is the ______.
Control center
Blood pressure decreases below normal levels. Blood flow to the heart decreases. Heart is unable to pump as much blood. Blood pressure decreases even more. This is an example of _____ feedback.
Positive
(In positive feedback, the initial stimulus is reinforced. Here blood pressure decreases, something happens and blood pressure drops even more. This is an example of a harmful positive feedback mechanism).
A sweat gland can adjust temperature when directed. A sweat gland is an example of a(n) ______.
Effector
A feedback mechanism that represents a cycle where physiological change leads to an even greater change in the same direction is a ______.
Positive feedback
In a feedback mechanism a stimulus is detected by a(n) ______.
Receptor
Sweating in response to an increase in body temperature is part of a __ feedback mechanism to lower body temperature
Negative
True or false: Positive feedback mechanisms are less common in healthy individuals than negative feedback mechanisms.
True
Positive feedback increases the deviation from homeostasis, and therefore, is rarely seen in health
True or false: During some situations, there are beneficial deviations from body set points.
True
Sometimes deviations are beneficial, such as the changes in heart rate and blood pressure seen in exercise
Body temperature decreases. Shivering occurs. Body temperature increases. This is an example of _____ feedback.
Negative
(In negative feedback, the response is opposite the original stimulus. Negative feedback maintains homeostasis. In this case there is a decrease in temperature and the body responds to increase temperature back to the normal range).
In positive feedback, the response to the original stimulus ______.
Increases
Positive feedback mechanisms are more commonly seen in ______ individuals.
Unhealthy
