Unit 9: Body Systems and Homeostasis
Name: Date:
Aim #64 Feedback Mechanisms:How do Feedback Mechanisms Maintain Homeostasis?
- Dynamic Equilibrium: Changes made to maintain a steady state
Our bodies are constantly monitoring, responding and adjusting to internal and external______(changes). Organisms have a variety of mechanisms that ______their internal environment and bring their body back to normal. Examples of small changes that occur to bring back the body’s stability arechanges in our body temperature and changes in blood sugar level. We refer to constant small changes as ______. It is because of these small changes that we maintain ______(balance).
Responses to Environmental Change
ORGANISM / CHANGE (stimulus) / RESPONSE
Species of Bacteria / Temperature falls below a certain point / Bacteria produces a chemical that acts as ______
Many Plants / Air is hot and dry and there is a shortage of water / Leaf pores (stomates) ______to conserve______
Monarch Butterflies / Seasons change
Human / Person hears a loud noise / The person becomes ______; heart rate ______for “fight or flight”
Human / Person’s temperature increases / The person begins to ______, which ______down the body
- Negative Feedback
A feedback mechanism involves ______and ______to a stimulus (change
in the environment) by “feeding back” to ______or ______an action taken by the system.
These mechanisms keep that body at a ______and ______state.
NEGATIVE FEEDBACK: a change in the environment (stimulus) can prompt system 1 to send a message (often a ______) to system 2, which responds by attempting to restore ______and bring the body back to ______. When system 1 detects that system 2 has acted, it ______signaling for further action.
Negative Feedback Mechanisms in our Body:Our bodies act as a “thermostat” in a similar way.
a)Regulating Body Temperatureb) Regulating Blood Glucose Level
People who have diabetes are unable to produce enough insulin or their body cannot respond to the insulin causing them to have high blood sugar. This is why they take insulin injections.
Diabetes is a disease characterized by consistently high blood glucose levels (at or above 126 mg/l00mL) as a result of hormone deficiency. For a study of diabetes, blood glucose levels from individualAand individualBwere recorded each hour over a 5-hour period following a meal. The results are shown in the data table below.