Homeostasis 2022

Which of the following is an example of positive feedback?

• Thermoregulation

• Blood Pressure

• Childbirth

• Blood Sugar Levels

Homeostasis

• allows for a wildly fluctuating internal environment
• is impossible in vertebrates
• is the maintenance of a relatively stable internal environment and often incorporates a form of feedback regulation
• is the maintenance of a relatively stable external environment and often incorporates a form of feedback regulation

When you get cut, your skin cells release hormones that signal platelets to come and stop the bleeding. Platelets then release more hormones that signal even more platelets to help stop bleeding. The hormone signals continue until the cut is closed.

• Positive Feedback Response
• Negative Feedback Loop 

Homeostasis in the human body is often maintained by a: 

• neutral feedback loop 
• solar feedback loop
• positive feedback loop
• negative feedback loop

The "cause" for something to happen is the

• response
• effect
• stimulus
• homeostasis

The graph above shows changes in body temperature of an endotherm with time.

Which one of the following accurately describes the regulatory mechanism shown in the graph?

• A - Negative feedback

• B - Positive feedback

• C - Thermoregulation

• Both A and C

Which best describes the stimulus-response model?

• Stimulus -> receptor -> effector -> control center -> response

• Stimulus -> receptor -> control centre -> effector -> response

• Stimulus -> effector -> control center -> receptor -> response

Positive feedback is when the change caused by the stimulus is

• decreased
• non existant
• increased
• changes constantly

When you are cold, you shiver and your blood vessels contract, which warms you up. When you are hot, you sweat and your blood vessels expand, which cools you down.  

• Positive Feedback Response
• Negative Feedback Loop