Honors: Homeostasis: Positive & Negative Feedback

Feedback Mechanism Parts In the left column the parts of a negative feedback mechanism have been listed. In the right column place the parts in the correct order. Response Stimulus Stimulus Receptor Receptor Control Center Control Center Effector Effector Response Fill in the blanks with the correct term. Homeostasis is the existence and maintenance of a constant environment in the body. Positive feedback will make the deviation away from the normal value even greater. Negative feedback will return the body back to its normal values to maintain homeostasis. Feedback mechanism functions Match the feedback term with its description. How the body reacts to problem Response The problem the body experiences Stimulus Body part that regulates the problem Control Center Body part that senses the problem Receptor Body part that creates the response Effector Identify Mechanism Parts Read the following example and then complete the chart below by identifying the parts of the feedback mechanism from the example.After a woman delivers a baby she may decide to breast feed. In order to do that her body must produce milk and continue to produce milk as long as the baby feeds. When the baby puts pressure on the breast while sucking for milk, sensory receptors in the breast will send a signal to the hypothalamus. The hypothalamus will produce the hormone called oxytocin which is released by the pituitary gland. The oxytocin will reach the lobules in the mammary glands of the breast and cause them to produce milk. Feedback Mechanism Part Example from Paragraph Explanation Stimulus No milk production Receptor Pressure receptors in breast Control Center Pituitary gland (releases oxytocin) Effector Lobules in mammary gland (release milk) Response Increase in milk production Identify Mechanism Parts Read the following example and then complete the chart below by identifying the parts of the feedback mechanism from the example.The control of blood sugar (glucose) by insulin is a good example of a negative feedback mechanism. When blood sugar rises, receptors in the body sense a change. In turn, the beta cells in the pancreas secretes insulin into the blood causing the liver body cells to take glucose into their cells, effectively lowering blood sugar levels. Once blood sugar levels reach homeostasis, the pancreas stops releasing insulin. Feedback Mechanism Part Example from Paragraph Explanation Stimulus Blood sugar increases Receptor Glucose receptors in the body Control Center The pancreas (beta cells release insulin) Effector Liver body cells uptake glucose Response Lowering blood sugar Fill in the blanks with the correct term. The regulation of blood glucose is an exam of a negative feedback loop, because it will return the body back to its normal set point.The production of milk is an example of a positive feedback loop, because it causes an increase away from the normal set point.