Define homeostasis IN YOUR OWN WORDS 10/21/15 Date:10/21/15Topic:Homeostasis ReviewPage # ___ Today in Room 311 ADMIT SLIP: Define homeostasis in own words HW: Research which materials are allowed to enter cell through the membrane CONTENT OBJ: SWBAT explain how the nervous system helps maintain homeostasis in the body LANG. OBJ: SWBAT label the parts of a cell membrane AGENDA: Signaling Review Homeostasis Mini Labs Cell Membrane Notes POGIL EXIT SLIP: Write down one thing you learned & 1 question Date:10/21/15Topic:Homeostasis ReviewPage # ___ Homeostasis? = your bodys mechanisms for maintaining stable and safe conditions = your bodys mechanisms for maintaining stable and safe conditions Which body system directs all the mechanisms? (Recognizes signs/symptoms and sends signals) The Nervous System! Homework Review: Signaling Homeostasis Test: Heart Rate Find your pulse Count for 15 sec Homeostasis Test: Heart Rate Now exercise for one minute. Everyone stand up. You can run in place or do jumping jacks. Ready go! Now quickly find pulse and we will take it again for 15 sec Homeostasis Test: Heart Rate **Start Timer* (2 min) Resting heart rate: Take # and multiply by 4 = # beats/minute After exercise: Take # and multiply by 4 = # beats/minute How do they compare? Homeostasis Test: Heart Rate Why did your heart rate speed up? This is part of homeostasis After two minutes of resting, what will happen to your heart rate? This is part of homeostasis too! Your body speeds up your heart when needed, but then returns to stable conditions when possible. How did your temperature change? What type of feedback mechanism is this??? Homeostasis Mechanisms Generally, the body uses NEGATIVE FEEDBACK to keep you alive and healthy Think: Thermostat You want the heat on, but you want it to turn off when it gets warm. Otherwise everything would eventually burn. Positive Feedback Homeostasis: Pupil Size How does your pupil maintain homeostasis for the body? Lets see Use your phone to take a picture of yourself (without flash) Use your phone to take a picture of yourself WITH FLASH Look at your pupils in each. How do they compare? Homeostasis Big vs. Small Large scale homeostasis = Body mechanisms Control center = brain Control pathway = Nervous system Small scale homeostasis = Cellular mechanisms Control center? Cell membrane (Why?) Cell Membrane Video https://www.youtube.com/watch?v=6fhbbFd4icY (For later: https://www.youtube.com/watch?v=moPJkCbKjBs) https://www.youtube.com/watch?v=moPJkCbKjBs Cell Membrane: Body Guard of the Cell* Composed of phospholipids* Hydrophilic Head Hydrophobic Tail Copy this: Copy into journal* (w/ all labels) How does anything get through? Functions of Cell Membrane* Thoughts? Holds cell together Gives flexibility to cell (not rigid) Keeps materials (organelles) inside Allows some materials to enter/leave POGIL Begin packet (we will continue tomorrow) Work with a partner if needed Homework Research what materials are allowed to enter the cell through the cell membrane. Write a bulleted list.