1. Feedback loops
12/28/2018

2. Good morning! On the next page of your notebook do the following:
Title the page:
Feedback Loops
Make sure that you put it in your table of contents
Underneath the title, write this essential question:
EQ: How does your body maintain homeostasis?
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3. Pregnancy manipulative
In groups of 4, 5 or 6 do the pregnancy manipulative
Draw a diagram in your notebook demonstrating what happened
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4. What are feedback loops?
Feedback loops are how we maintain homeostasis (same/equal)
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5. What are the 2 types of feedback loops?
Positive
Negative
Not common
Most common
Increases original change detected by receptors
Reversing a change in the internal environment
Ex: pregnancy, apples ripening
Ex: temperature control, diabetes, speeding
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6. What do feedback loops look like?
Change is detected
Corrective response activated
Body condition returned to normal range
Corrective response switched off
Body condition leaves acceptable range
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7. What are the parts of a feedback loop?
Stimulus – an action that evokes a response
Receptor – a sensory organ, monitors body conditions, 1st thing to figure out problem
Control center – brain interprets input from receptors and sends signals to effector
Effector – organ that acts in response
Response – action caused by effector
stimulus
receptor
Control center
effector
response
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8. What are some examples of feedback loops?
Speeding:
Negative
Stimulus – running late -> increase speed
Receptor – eyes see sign and high speed
Control center – brain
Effector – foot muscles
Response – slow down to desired speed
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9. What are some examples or feedback loops?
Temperature change
Negative
Stimulus – body temperature rises
Receptor – skin cells
Control center – brain
Effector – sweat glands
Response – sweat, lowers body temp
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10. What are some examples of feedback loops?
Temperature change
Positive
Stimulus – too cold
Receptor – skin cells
Control center – brain
Effector – muscles
Response – goose bumps, shiver, heat up
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11. In pairs or groups choose a scenario and make a feedback loop in your journal
Scenario 1: Blood Glucose:
You eat a HUGE piece of birthday cake. After eating the high amount of sugar, our blood sugar rises. After it rises, the endocrine system signals the pancreas to release insulin. The insulin is release from the pancreas which travels through the bloodstream to cells. This insulin helps the body cells to take in glucose which helps to lower the amount of sugar in the bloodstream. After the blood sugar lowers and the glucose levels fall, the insulin release is inhibited.
Scenario 2: Water Balance:
Perhaps you have not drunk anything for a while or you have been sweating a lot. Part of the brain, the hypothalamus, detects that there is not enough water in the blood. The hypothalamus sends a message to the pituitary gland which releases ADH. This travels in the blood to your kidneys and affects the tubules so more water is reabsorbed into your blood. As a result you make a smaller volume of more concentrated urine. The level of water in your blood increases until it is back to normal.
12/28/2018

12. Homeostasis lab
Work in groups on lab
Due next class
12/28/2018