Now that you've had a chance to think about this on your own and also see some of your classmates' ideas, let's take a chance to record your final thoughts (for now) on the prompt below.  Unlike in the previous page, this response will be graded for accuracy for up to 10 points.  Please try your best, but also realize this is a safe place to make mistakes and voice confusions.  You will have opportunities to revise your answers and increase your understanding if necessary.  Feel free to open up another window so you can refer back to earlier discussion boards or other pages in this module!

Prompt:

One cause of osteoporosis is low calcium. You have a special gland that has calcium sensors. If it detects low calcium in your blood, the gland sends hormones to your bone cells. Your bone cells then break down and weaken your bones in order to release calcium. This results in higher calcium in your blood.

1)What is the control center in this example?

2)What is the effector in this example?

3)Does this example show negative feedback or positive feedback? How can you tell?

Mostly Complete (10 pts): 1. Gland is the control center (determines that calcium is low and should be raised), 2. Bone cells are effectors (they complete the action that changes calcium levels), 3. Negative feedback - justify this by discussing how changes at the end of the feedback loop relate to the initial deviation or to the set point.

Partially Complete (6 pts): Some of above answers incorrect or missing evidence/reason for type of feedback chosen.