Sponge: Set up Cornell Notes on pg. 9 Topic: 1.3 Homeostasis Essential Question: Define Homeostasis and explain its importance to survival 2.1 Atoms, Ions, and Molecules Define Homeostasis and explain its importance to survival 1.3 Homeostasis

2 Title pg. 8 Homeostasis On the 1 st line of pg. 8 title “Body Story: Body Snatchers” *Focus on the changes of the body after being infected with influenza virus Body Story: Body Snatchers

3 1.What does the virus do to her cells? 2.What causes Holly’s pain symptoms? Why? 3.Your body has a natural thermostat (98.6). Why does her body react with a fever? 4.Why was it “good” that Holly couldn’t find pain medicine? 5.Why does it take the body so long to find the helper T and B cells? 6.The video said the specific T cell had been “waiting for 25 years” Hypothesize where you think she got it from?

4 1. What does the virus do to her cells? “Hijacks her cell”- forces it to produce more of the virus 2. What causes Holly’s pain symptoms? Why? Holly’s body is creating the pain symptoms. This lets her know that something is wrong- It is the result of her body fighting the invader. Allows her to “rest” so her body can use her energy to fight the invader. 3. Your body has a natural thermostat (98.6). Why does her body react with a fever? 98.6 allows for a perfect “breeding ground” for the virus. By heating up her body the virus cannot produce at such a fast rate. 4. Why was it “good” that Holly couldn’t find pain medicine? Pain medicine would reduce her fever, allowing the virus to produce at its full rate. 5. Why does it take the body so long to find the helper T and B cells? They are only 2 cells in trillions. Your body needs to locate the proper cells to fight the virus. 6. The video said the specific T cell had been “waiting for 25 years” Hypothesize where you think she got it from? She was born with it. Passed on from her mother to her.

5 On the bottom of pg. 8: Recall from Biology… What is homeostasis? At what temperature is your body in homeostasis? How does your body react to temperature increase? Temperature decrease?

6 Recall from Biology what homeostasis is. At what temperature is your body in homeostasis? 98.6 degrees How does your body react to temperature increase? Sweat Temperature decrease? Shivering

7 An ameoba is a unicellular organism that lives in lakes or ponds Have organelles just like us Limited ability to move Survives depending on the conditions of the environment Any extreme changes in the environment will kill it

8 Human Internal Environment protects our cells from external changes is relatively constant, despite an ever- changing outside environment (98.6 degrees)

9 Homeostasis Homeostasis: Body’s maintenance of a stable internal environment. It is so important that it requires most of our metabolic energy

10 Your control center (brain) is like a thermostat Has a set temperature (98.6) If it is too hot- sends signals to effectors to lower body temp (ex: sweat) If too cold- sends signals to effectors to raise body temp (ex: shiver) How does a thermostat work? Air conditioner Heater

11 Homeostatic Mechanisms – monitors aspects of the internal environment and corrects any changes Stimuli- Something that stimulates change (cause) Receptors – provide information about specific conditions (stimuli) in the internal environment. Control center - (Usually the brain) detects the change from the set point (ex: 98.6) and sends signals to effector organs Effectors – such as muscles and glands, elicit responses that alter conditions in the internal environment and return conditions to normal Response – behavior that results (effect)

12 Homeostatic Mechanisms Change occurs

13 Homeostatic Mechanisms Receives information and sends signals to the control center

14 Homeostatic Mechanisms The brain detects the difference from the “set point” and signals effector organs

15 Homeostatic Mechanisms Work to return the body to balanced levels

16 Homeostatic Mechanisms Body returns to homeostasis

Homeostatic mechanism regulates body temperature Slide number: 1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Control center The brain detects the deviation from the set point and signals effector organs. Receptors Thermoreceptors send signals to the control center. Effectors Skin blood vessels dilate and sweat glands secrete. Stimulus Body temperature rises above normal. Response Body heat is lost to surroundings, temperature drops toward normal. too high too low Normal body Temperature 37 o C (98.6 o F) Stimulus Body temperature drops below normal. Response Body heat is conserved, temperature rises toward normal. Receptors Thermoreceptors send signals to the control center. Effectors Skin blood vessels constrict and sweat glands remain inactive. Effectors generates body heat. Control center The brain detects the deviation from the set point and signals effector organs. If body temperature continues to drop, control center signals muscles to contract involuntarily.

Homeostatic mechanism regulates body temperature Slide number: 2 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Stimulus Body temperature rises above normal. too high Normal body Temperature 37 o C (98.6 o F)

Homeostatic mechanism regulates body temperature Slide number: 3 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Receptors Thermoreceptors send signals to the control center. Stimulus Body temperature rises above normal. too high Normal body Temperature 37 o C (98.6 o F)

Homeostatic mechanism regulates body temperature Slide number: 4 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Control center The brain detects the deviation from the set point and signals effector organs. Receptors Thermoreceptors send signals to the control center. Stimulus Body temperature rises above normal. too high Normal body Temperature 37 o C (98.6 o F)

Homeostatic mechanism regulates body temperature Slide number: 5 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Control center The brain detects the deviation from the set point and signals effector organs. Receptors Thermoreceptors send signals to the control center. Effectors Skin blood vessels dilate and sweat glands secrete. Stimulus Body temperature rises above normal. too high Normal body Temperature 37 o C (98.6 o F)

Homeostatic mechanism regulates body temperature Slide number: 6 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Control center The brain detects the deviation from the set point and signals effector organs. Receptors Thermoreceptors send signals to the control center. Effectors Skin blood vessels dilate and sweat glands secrete. Stimulus Body temperature rises above normal. Response Body heat is lost to surroundings, temperature drops toward normal. too high Normal body Temperature 37 o C (98.6 o F)

too low Normal body Temperature 37 o C (98.6 o F) Homeostatic mechanism regulates body temperature Slide number: 7 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Stimulus Body temperature drops below normal.

Receptors Thermoreceptors send signals to the control center. too low Normal body Temperature 37 o C (98.6 o F) Homeostatic mechanism regulates body temperature Slide number: 8 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Stimulus Body temperature drops below normal.

Receptors Thermoreceptors send signals to the control center. too low Normal body Temperature 37 o C (98.6 o F) Homeostatic mechanism regulates body temperature Slide number: 9 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Stimulus Body temperature drops below normal. Control center The brain detects the deviation from the set point and signals effector organs.

Receptors Thermoreceptors send signals to the control center. too low Normal body Temperature 37 o C (98.6 o F) Homeostatic mechanism regulates body temperature Slide number: 10 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Stimulus Body temperature drops below normal. Control center The brain detects the deviation from the set point and signals effector organs. If body temperature continues to drop, control center signals muscles to contract involuntarily.

Effectors Skin blood vessels constrict and sweat glands remain inactive. Receptors Thermoreceptors send signals to the control center. too low Normal body Temperature 37 o C (98.6 o F) Homeostatic mechanism regulates body temperature Slide number: 11 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Stimulus Body temperature drops below normal. Effectors Muscle activity generates body heat. Control center The brain detects the deviation from the set point and signals effector organs. If body temperature continues to drop, control center signals muscles to contract involuntarily.

Effectors Skin blood vessels constrict and sweat glands remain inactive. Receptors Thermoreceptors send signals to the control center. too low Normal body Temperature 37 o C (98.6 o F) Homeostatic mechanism regulates body temperature Slide number: 12 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Stimulus Body temperature drops below normal. Response Body heat is conserved, temperature rises toward normal. Effectors Muscle activity generates body heat. Control center The brain detects the deviation from the set point and signals effector organs. If body temperature continues to drop, control center signals muscles to contract involuntarily.

Sponge: Set up Cornell Notes on pg. 11 Topic: 1.3 Homeostasis: Negative and Positive Feedback Essential Question: Compare and Contrast Negative and Positive feedback in a double- bubble map on the bottom of pg Atoms, Ions, and Molecules Compare and Contrast Negative and Positive Feedback in a double-bubble on the bottom of pg Homeostasis: Negative and Positive Feedback

30 On the top of pg. 10 (no more than 5 lines) 1.What is homeostasis? 2. How do your control center and effectors work together to maintain homeostasis? 3. Give an example. Sponge:

31 1.What is homeostasis? The body’s maintenance of a stable internal environment 2. How do your control center and effectors work together to maintain homeostasis? The brain sends signals to specific effectors (muscles or glands) that will then respond to the changes and bring back conditions to normal 3. Give an example. The body’s temperature drops to 96 degrees. The brain signals the skeletal muscles to contract and relax repeatedly generating heat (shivering)

32 On the bottom of pg. 9: Using your Homeostasis effector and response sheet, write a paragraph describing the process of homeostatic mechanisms for either: A) You have caught the flu and your temperature is now at 103 degrees B) You are outside playing in snow and your body temperature is dropping due to the surrounding environment Pg. 11 Figure 1.8 Pg in book Tell it like a story… Start with stimulus Be specific with Effectors!!! What muscles and/or glands are at work? What is your body’s response or behavior? Thermoreceptors Hypothalamus

Receptors measure deviations from the “set point” Effectors are activated to return conditions toward normal As conditions return toward normal, the deviation from the “set point” lessens, and the effectors gradually shut down. Such a response is called a negative feedback mechanism Deviation from set point Negative feedback = deviation from “set point” lessens

34 Stimulus: rising blood sugar Response: blood sugar returns to normal= homeostasis Negative Feedback: The control system (brain) sends signals/instructions to effectors (muscles and glands) to stabilize the body activated by an imbalance corrects an imbalance, brings body back to Homeostasis Pancreas receptors detect high blood sugar The control center signals the pancreas to secrete insulin Effector: Insulin causes liver cells to take up sugar in the blood

35 Stimulus: rising blood sugar Response: blood sugar returns to normal= homeostasis Pancreas receptors detect high blood sugar The control center signals the pancreas to secrete insulin Effector: Insulin causes liver cells to take up sugar in the blood Middle of pg. 10 NEGATIVE FEEDBACK MECHANISM

Temperature Regulation:

Examples of negative feedback : Temperature regulation Blood pressure regulation Blood sugar regulation Most feedback in the body is negative!!!!

38 Positive Feedback: Process by which changes cause additional similar changes away from the normal state, producing unstable conditions Usually short lived Can be cancelled or reduced by negative feedback Ex: Blood Clotting

Blood Clotting

40 Stimulus: Receptors: Control Center: Effectors: Response: Bottom of pg. 10 POSITIVE FEEDBACK MECHANISM

Examples of positive Feedback mechanisms Blood clotting Childbirth

42 Homework On the bottom of pg. 11 draw a double- bubble map, comparing and contrasting negative and positive feedback. Make sure you give examples of each.

43 Negative Feedback Positive Feedback Corrects an imbalance Ex: temperature regulation Returns body to homeostasis Causes additional changes Ex: Contractions during childbirth Moves body away from homeostasis stimuli receptors Control center effectors