Homeostasis | Biology for JAMB PDF Download

Homeostasis:

A human being is shaped by millions of cells that are working together for the maintenance of all organs in a human body. All cells require quite the similar metabolism but they perform different functions. For the well-being for the entire human organism, every individual cell needs to maintain the internal environment like glucose, oxygen, mineral ions and waste removal.

The process that a body maintains internally is collectively called as homeostasis. The concept of homeostasis was first described in 1865 by a French Physiologist named Claude Bernard, but the word was first used in 1926 by Walter Bradford Cannon.

What is Homeostasis?

Homeostasis is a property of a human biological system where the self-regulating process tends to maintain the balance for the survival. The regulation takes place in a defined internal environment. For example, the regulation of body temperature, glucose in blood plasma, extracellular fluids of an animal changes despite what the animal has eaten or what it is doing. Every variable is controlled by homeostasis together to maintain life.

In simple terms, it could be referred as a balance in a system to maintain a stable internal environment for the survival of the animal. If the homeostasis regulates successfully, life continues or if unsuccessful, death or disaster occurs.

The regulation by homeostasis consist of three mechanisms:

1. Receptor
2. Control Center
3. Effector

Receptor: The receptor acts as a receiver. It receives the changes in the environment.

Control Center: The Control Center is also known as integration center. It receives all the information that the receptor has collected from the changes in the environment.

Effector: As the name suggests, it responds to the commands of the control center. It could either oppose or change the stimulus.

The entire process continuously works to maintain the homeostasis regulation. For instance, the regulation of body temperature, there are receptors in the skin, that communicates information to the brain, which acts as the control center and the blood vessels (effector) and sweat glands in our skin maintain the temperature.

Examples of physiological homeostasis:

1. Arterial blood pressure homeostat.
2. Blood glucose homeostat.
3. Blood oxygen content homeostat.
4. Blood partial pressure of oxygen and carbon dioxide homeostasis
5. Core body temperature homeostat.
6. Extracellular fluid pH homeostat.
7. Extracellular potassium concentration homeostat.
8. Extracellular sodium concentration homeostat.
9. Plasma ionized calcium homeostat.
10. Volume of body water homeostat.

Homeostasis Breakdown:

The failure of homeostasis function in an internal environment will result in many diseases. A functional component of homeostasis can malfunction due to an inherited defect or by affected disease. Few homeostasis has the capability of inbuilt redundancy, ensuring safer life even if a homeostasis component malfunctions. However, in other cases, a malfunction in any component of homeostasis leads to severe disease or death.

Body Systems and Homeostasis:

The body system participates in maintaining homeostasis regulations. The function of body system describes various regulatory mechanisms where every system is contributed to homeostasis. Here are few tables that describe the function of every organs homeostasis.