Human homeostasis is the body’s physiological ability to regulate its inner environment. All processes in the body are controlled within narrow limits and must run efficiently at optimum level in order for the body to stay healthy. These processes include body temperature, ion balance, waste removal and blood glucose concentration.
The Roles of Homeostasis in the Human Body
1. Controlling Body Temperature
The thermoregulatory centre is responsible for monitoring and controlling body temperature, making sure the body doesn’t overheat or become under insulated.
Human enzymes perform at an optimum level of 37 ºC, so this is the temperature the body seeks to operate at. The thermoregulatory center gathers information from temperature receptors in the brain and the skin. When the body is too hot there are a number of ways in which the body cools itself down.
- 2. Cooling Down
Sweating is one way in which the body combats overheating. Sweat glands release sweat which evaporates and removes heat from the skin. Another method of cooling the body down is when blood vessels leading to the skin capillaries widen and dilate, thus allowing blood to flow through the skin and heat to escape.
3. Heating Up
When we get too cold our body instructs the muscles to contract causing shivers. These contractions create heat which is then used to regulate body temperature. In an opposite manner to being too hot, the blood vessels leading to the skin capillaries become narrower to stop heat escaping. Hairs on the body also lie flat, trapping a layer of oxygen above the skin which heats up and insulates the body.
4. Ion Balance
When we sweat we lose ions such as sodium ions and chloride ions. These can be replaced by drinking and eating. Many athletes use electrolyte drinks during and after exercise to replace ions and keep the body healthy and energetic. Cells can be damages if the ion content is imbalanced. The loss of ions signals the importance of remaining hydrated during exercise and in hot weather conditions.
5. Blood Sugar Levels
The pancreas monitors and controls blood glucose levels by releasing insulin, a hormone that reduces glucose levels in the blood. Insulin causes glucose to move from blood into the cells and lowers blood glucose levels when they become too high. This is likely to happen after consuming food that is rich in carbohydrates such as, bread, rice, pasta, potatoes and sweets. Those with an inability to regulate blood glucose levels with insulin have diabetes, a potentially fatal disease that requires constant monitoring.
6. Waste Removal
The body must retain the ability to remove waste such as carbon dioxide and urea. Carbon dioxide is a product of aerobic exercise and is released through the lungs. Urea is a product of excess amino acid production removed by the kidneys. The kidneys remove urea from the blood by producing urine which is temporarily stored in the bladder. If waste is left in the body it will cause negative chemical reactions and damage cells.
The human body is a complex and amazing machine and the role of homeostasis in our existence is just one more example of this.