1. Big Bang Theory https://www.youtube.com/watch?v=9RLnlXNlfdk

2. Homeostasis

4.  Homeostasis—maintenance of a stable internal environment  A dynamic state of equilibrium  Homeostasis is necessary for normal body functioning and to sustain life  Communication within the body is essential  Nervous and endocrine system (nerves and hormones)

5. Feedback Loop Terms  Receptor: a sensory organ  Stimulus: an action that evokes a response  Effector: an organ that acts in response  Response: the caused action of the effector  Control Center: determines the level at which a variable is to maintained, analyzes info, determines response

7. Figure 1.4, step 1a Variable (in homeostasis)

8. Figure 1.4, step 1b Stimulus: Produces change in variable Variable (in homeostasis) Imbalance

9. Figure 1.4, step 2 Change detected by receptor Stimulus: Produces change in variable Receptor (sensor) Variable (in homeostasis) Imbalance

10. Figure 1.4, step 3 Change detected by receptor Stimulus: Produces change in variable Input: Information sent along afferent pathway to Receptor (sensor) Variable (in homeostasis) Control center Imbalance

11. Figure 1.4, step 4 Change detected by receptor Stimulus: Produces change in variable Input: Information sent along afferent pathway to Receptor (sensor) Effector Variable (in homeostasis) Output: Information sent along efferent pathway to activate Control center Imbalance

12. Figure 1.4, step 5 Change detected by receptor Stimulus: Produces change in variable Input: Information sent along afferent pathway to Receptor (sensor) Effector Variable (in homeostasis) Response of effector feeds back to influence magnitude of stimulus and returns variable to homeostasis Output: Information sent along efferent pathway to activate Control center Imbalance

13. Feedback Loop  Receptor: a sensory organ  Stimulus: an action that evokes a response  Effector: an organ that acts in response  Response: the caused action of the effector

14. Feedback Loop Practice (speed sign)  Receptor: a sensory organ  Stimulus: an action that evokes a response  Effector: an organ that acts in response  Response: the caused action of the effector

15. Feedback Loop Practice (thermostat)  Receptor: a sensory organ  Stimulus: an action that evokes a response  Effector: an organ that acts in response  Response: the caused action of the effector

16. Feedback Loop Practice (thermostat)  Receptor: a sensory organ  Stimulus: an action that evokes a response  Effector: an organ that acts in response  Response: the caused action of the effector

17. Thermoregulation

18. Capillaries Sweat Glands Muscles Capillaries Body Hair

19. Cells….Tissues….Organs (Shivering)  Muscles Cells: ions move in and out to trigger contraction

20. Cells….Tissues….Organs (Shivering)  Muscles Cells: ions move in and out to trigger contraction  Individual muscle cells contract  Active transport of ions on a cellular level

21. Cells….Tissues….Organs (Shivering)  Muscles Tissue: Chemicals move from one cell to another to contract many cells

22. Cells….Tissues….Organs (Shivering)  Muscles Tissue: Chemicals move from one cell to another to contract many cells  Acetylcholine (Ach)  Binds to receptors on cells

23. Cells….Tissues….Organs (Shivering)  Whole Muscle (Ex. Bicep): Once at the level of tissue contraction it is a chain reaction and the whole muscle will contract and relax repeatedly. OVER AND OVER AGAIN

24. Blood Glucose  Read the article titled Insulin and Glucagon  Work in a groups of 2-3 to construct a negative feedback loop like we practiced  Identify receptor, effectors, stimuli, and responses  Draw and label a negative feedback loop

25. Blood Glucose Body Cells Liver Liver

26. Blood Glucose Body Cells Liver Liver Insulin (Beta Cells)

27. Blood Glucose Body Cells Liver Liver Insulin (Beta Cells) Glucagon (Alpha Cells)

28. Positive Feedback Mechanisms  Positive feedback  Increases the original stimulus to push the variable farther  In the body this only occurs in blood clotting and during the birth of a baby  Or when a person goes into shock which  https://www.youtube.com/watch?v=heWOEkjutHc

29. HOMEOSTASIS LAB