Homeostasis

Biological homeostasis is the ability of the body to maintain relative stability and function even though drastic changes may take place in the external environment or in one portion of the body.

Homeostasis is maintained by a series of control mechanisms, some functioning at the organ or tissue level and others centrally controlled. The major central homeostatic controls are the nervous system and endocrine system.

An example of a homeostatic mechanism is your dog’s body reaction to anemia and hypoxia (low tissue oxygen). Erythropoiesis (the making of red blood cells) is controlled primarily by the hormone erythropoietin. Hypoxia is the stimulus that interacts with the heme protein that signals the kidney to produce erythropoietin. This, in turn, stimulates the bone marrow to increase red blood cells and hemoglobin, raising the ability of the blood to transport oxygen and thus raise the tissue oxygen levels in the blood and other tissues. This rise in tissue oxygen levels serves to suppress further erythropoietin synthesis (a feedback mechanism)
Dogs’ internal body temperature is another great example of homeostasis. When your dog is healthy, his body temperature is around 101 to 102.5 degrees. The body controls temperature by making or releasing heat.
Glucose is a type of sugar that is found in the bloodstream, but the body must maintain proper glucose levels to ensure that a dog remains healthy. When glucose levels get too high, the pancreas releases a hormone known as insulin. If blood glucose levels happen to drop too low, the liver converts glycogen in the blood to glucose again, raising the levels.
When bacteria or viruses that can make you ill get into your body, your lymphatic system kicks in to help maintain homeostasis. It works to fight the infection before it has the opportunity to make you sick, ensuring that you remain healthy.
The maintenance of healthy blood pressure is an example of homeostasis. The heart can sense changes in the blood pressure, causing it to send signals to the brain, which then sends back signals telling the heart how to respond. If blood pressure is too high, naturally the heart should slow down; while if it is too low, the heart wants to speed up.
Your dog’s body contains chemicals known as acids and bases, and a proper balance of these is required for the body to function optimally. Lungs and kidneys are two of the organ systems that regulate acids and bases within the body.
About 60% of a dog’s body weight percentage is water, and maintaining the correct balance of water is an example of homeostasis. Cells that have too much water in them bloat and can even self destruct. Cells with too little water can end up shrinking. Your dog’s body maintains a proper water balance so that neither of these situations occurs.
Calcium levels in the blood must be maintained at proper levels. The body regulates those levels in an example of homeostasis. When levels decrease, the parathyroid releases hormones. If calcium levels become too high, the thyroid helps out by fixing calcium in the bones and lowering blood calcium levels.
Exercising causes the body to maintain homeostasis by sending lactate to the muscles to give them energy. Over time, this also signals to the brain that it is time to stop exercising, so that the muscles can get the oxygen they need.
The nervous system helps keep homeostasis in breathing patterns. Because breathing is involuntary, the nervous system ensures that the body is getting much needed oxygen through breathing the appropriate amount of oxygen.
When toxins get into the blood, they disrupt your dog’s homeostasis. Their body, however, responds by getting rid of these toxins via the urinary system. Your dog simply urinates the toxins and other nasty things that came from the blood, restoring homeostasis.