Download Homeostasis, Regulation, and Feedback Loops

Name ___________________________ Class ________ Date ___________
Homeostasis, Regulation, and Feedback Loops
How do systems interact to perform the function of regulation in
animals?
All of the systems within the body interact with one another to
keep an organism healthy. Although each system has specific
functions, they are all interconnected and dependent on one
another. The nervous system controls various organs of the
body directly. The brain also receives information from many
organs of the body and adjusts signals to these organs to
maintain proper functioning. This helps to maintain a
relatively constant internal environment for cells and tissue, a
process known as homeostasis.
Feedback Loops
When a change occurs in the body, there are two general ways that the body can respond: negative
feedback or positive feedback
In negative feedback, the body systems make
adjustments to return the body back to normal after a
disturbance. Because this tends to keep things
constant, it allows us to maintain homeostasis. This
kind of feedback is used most often in the body. An
example of negative feedback is the regulation of body
temperature. When there is a change in body
temperature, sensory nerves will send a signal to a
part of the brain called the hypothalamus. The
hypothalamus processes this information and decides whether to raise or lower body temperature. The
hypothalamus then stimulates the release of chemical signals that affect things such as sweating,
shivering, and the rate of cellular metabolism throughout the body. In carrying out these functions, the
hypothalamus controls the endocrine system, which sends out
chemical signals, known as hormones, which move through the body
through the circulatory system.
On the other hand, positive feedback is also possible. This means body
systems make adjustments that call for more of the disturbance to
continue. This moves the body away from equilibrium, so it does not
result in homeostasis. Positive feedback is used in certain situations
where rapid change is desirable. An example of positive feedback is
childbirth. When a baby enters the birth canal by muscle contractions a
hormone called oxytocin stimulates the hypothalamus to produce more
oxytocin which increases uterine contractions. Another example is the
process of blood clotting. An injured tissue triggers platelets to stick to
the cut, and the platelets release chemicals calling for more platelets
and the formation of a blood clot.
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Name ___________________________ Class ________ Date ___________
1.
Define homeostasis.
2.
Define hormones.
3.
Define negative feedback. Explain how this relates to the concept of homeostasis?
4.
Define positive feedback. Explain how this relates to the concept of homeostasis?
5.
Which feedback will the body use the most often?
6.
Name at least three systems that are involved in regulating body temperature.
7.
Name at least three systems that are involved during contractions in childbirth.
Use the feedback loop to answer the questions
8.
Is blood glucose regulation an example of negative or positive feedback?
9.
What disrupted the homeostasis of glucose levels in the blood?
10. After the detection of high glucose levels, explain how the body returns to homeostasis.
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