Feedback loops 12/28/2018

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? 12/28/2018

Pregnancy manipulative In groups of 4, 5 or 6 do the pregnancy manipulative Draw a diagram in your notebook demonstrating what happened 12/28/2018

What are feedback loops? Feedback loops are how we maintain homeostasis (same/equal) 12/28/2018

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 12/28/2018

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 12/28/2018

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 12/28/2018

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 12/28/2018

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 12/28/2018

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 12/28/2018

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

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