Homeostasis & Feedback Mechanisms

When glucose levels in the blood rise, your brain sends a signal to your pancreas. The pancreas releases insulin, which opens channels in cell membranes to allow glucose to enter the cell, lowering blood sugar levels. This is an example of a:

• Positive Feedback Loop

• Negative Feedback Loop

Homeostasis

• allows for a wildly fluctuating internal environment
• is impossible in vertebrates
• is the maintenance of a relatively stable internal environment and often incorporates a form of feedback regulation
• is the maintenance of a relatively stable external environment and often incorporates a form of feedback regulation

Humans have ___ for body temperature, blood glucose concentrations, electrolyte concentrations, pH levels, tendon tension and variables.

• positive feedback mechanisms
• set points
• a wide internal range
• no regulation

If the calcium in your blood decreases below homeostasis levels, a gland in the brain will sense the decrease and send a chemical message to your bones. Your bones will release calcium into the blood, bringing blood calcium levels back up. This is an example of what type of feedback?

• Positive Feedback Response

• Negative Feedback Loop

As you get dehydrated, your blood becomes thicker and harder to pump. Your kidneys will respond by stopping urine production, sending the water from urine into your bloodstream to thin your blood back to normal level. This is an example of what type of feedback?

• Positive Feedback Response

• Negative Feedback Loop

This organ produces the hormones that help regulate blood glucose levels.

• pancreas
• liver
• small intestine
• gall bladder 

Detects change and sends a message to the control center

• receptor

• control center

• effector

• regulation

Receives the message from the receptor and coordinates a response

• control center

• effector

• glucagon

• homeostasis

The organ/cells that carry out the response

• control center

• receptor

• thermoregulation

• effector

_____________ is released by your pancreas when blood glucose levels get too high.

• glucose

• glucagon

• oxygen

• insulin