Any auto-regulating process that a biological system uses to maintain stability while continuously adjusting to surrounding conditions is part of homeostasis. These adjustments made by the body are necessary for survival. When the process of homeostasis is successful, life will continue. When it is unsuccessful, imbalance can ensue and can lead to death.
What is Homeostasis?
Homeostasis is quite crucial for the survival of organisms. It is often seen as resistance to changes in the external environment. Furthermore, homeostasis is a self-regulating process that regulates internal variables necessary to sustain life.
In other words, homeostasis is a mechanism that maintains a stable internal environment despite the changes present in the external environment.
A state of balance among all the body systems is needed for the body to survive and function correctly. In homeostasis, body levels of acid, blood pressure, blood sugar, electrolytes, energy, hormones, oxygen, proteins, and temperature are constantly adjusted to respond to changes inside and outside the body, to keep them at a normal level.
Also, Animal organs and organ systems constantly adjust to internal and external changes in order to maintain this steady state. Examples of internal conditions maintained homeostatically are the level of blood glucose, body temperature, and blood calcium level.
Homeostasis Definition
Homeostasis definition in biology is the ability or tendency of the body or a cell to seek and maintain a condition of equilibrium – a stable internal environment — as it deals with external changes. It makes use of feedback controls and other regulatory mechanisms in order to maintain a constant internal environment.
It can be construed as a skill of a living organism in its effort to stay within the optimal range despite the fluctuating environmental conditions. Thus, in the biological context, the word homeostasis entails multifarious physiological mechanisms in order to sustain and stabilize the functional, normal status of an organism.
Etymology: The term homeostasis comes from the Ancient Greek ὅμοιος (hómoios, meaning “similar”), from στημι (hístēmi, “standing still”) and stasis, from στάσις (stásis, meaning “standing”). The concept of homeostasis was first described in 1865 by Claude Bernard, a French physiologist. However, the term was coined later in 1962 by the American physiologist Walter Bradford Cannon. Variant: homoeostasis.
Why Is Homeostasis Important?
Homeostasis is the central uniting concept of physiology and self-regulation performed to maintain internal stability. Homeostasis is not constant. It is a dynamic process that changes internal conditions to promote survival.
Regulation via homeostasis is not a singular feedback cycle. It reflects the complex interaction of many feedback systems controlled by nerves and hormones. This feedback results in a precise level of control and flexibility that allows an organism to acclimate to changes in environmental conditions.
The life and health of an organism are the result of regulation via homeostasis. The disruption of homeostasis is what causes disease.
Proper treatment and therapy must be aimed at reestablishing conditions of homeostasis. Otherwise, severe disease or death could be imminent.
5 Examples of Homeostasis in the Human Body
The human body is an amazingly complex machine, but many of its parts and processes exist simply to maintain homeostasis. That is, the machine exists so the machine can continue to exist.
- Body Temperature: Body temperature control in humans is one of the most familiar examples of homeostasis. Normal body temperature hovers around 37 °C (98.6 °F), but a few factors can affect this value, including exposure to the elements, hormones, metabolic rate, and disease, leading to excessively high or low body temperatures. The hypothalamus in the brain regulates body temperature, and feedback about body temperature from the body is carried through the bloodstream to the brain, which results in adjustments in breathing rate, blood sugar levels, and metabolic rate.
- Blood Pressure: The system that maintains healthy blood pressure is an example of homeostasis. The maintenance of healthy blood pressure is one example of a homeostatic process, with the body responding to changes in blood pressure by sending signals to the brain. The brain interprets the signals and sends instructions to the heart to either speed up if blood pressure is too low or slow down if blood pressure is too high.
- Calcium Levels: Calcium levels in the body have to be within a range of acceptable parameters, and the body regulates this process through the release of hormones in another example of homeostasis. Thyroid hormones are responsible for regulating calcium levels, fixing calcium within the bones if the calcium levels become too high, which results in the lowering of calcium levels within the blood.
- Water Levels In The Body: Yet another example of homeostasis is the regulation of water levels in the body. Although more than half of the body’s weight is water weight, the cells of the body must have a balance of water within them. Cells that have too much water can bloat and even rupture while cells with too little water will shrink. When you are thirsty and intake water, this water is distributed to the cells that need it.
- Defending Against Infection: As a final example of homeostasis, consider how your body responds to different viruses or bacteria that get into it. Your lymphatic system is responsible for neutralizing these threats, working to resolve the issue and fight off the infection before it can take root within your body.
50 Examples of Homeostasis
- Blood glucose homeostasis
- Blood oxygen content homeostasis
- Extracellular fluid pH homeostasis
- Plasma-ionized calcium homeostasis
- Arterial blood pressure homeostasis
- Core body temperature homeostasis
- The volume of body water homeostasis
- Extracellular sodium concentration homeostasis
- Extracellular potassium concentration homeostasis
- Blood partial pressure of oxygen and carbon dioxide homeostasis
- Heart rate homeostasis
- Respiratory rate homeostasis
- Red blood cell count homeostasis
- White blood cell count homeostasis
- Platelet count homeostasis
- Blood pH homeostasis
- Intracellular calcium concentration homeostasis
- Intracellular sodium concentration homeostasis
- Intracellular potassium concentration homeostasis
- Intracellular magnesium concentration homeostasis
- Plasma protein concentration homeostasis
- Blood clotting factor concentration homeostasis
- Hormone levels homeostasis (e.g., insulin, glucagon, thyroid hormones)
- Serum cholesterol homeostasis
- Electrolyte balance homeostasis
- Acid-base balance homeostasis
- Cardiac output homeostasis
- Lung ventilation rate homeostasis
- Gastrointestinal pH homeostasis
- Kidney function and glomerular filtration rate homeostasis
- Urine osmolality homeostasis
- Sodium-potassium pump activity homeostasis
- Blood pressure baroreceptor reflex homeostasis
- Blood osmolarity homeostasis
- Body fluid volume homeostasis
- Body temperature regulation through sweating and shivering
- Oxygen and carbon dioxide exchange in the lungs
- Calcium absorption and excretion homeostasis
- Magnesium absorption and excretion homeostasis
- Iron absorption and utilization homeostasis
- Water reabsorption in the kidneys
- Maintenance of blood flow to vital organs during exercise
- Maintenance of blood flow to the brain during posture changes
- Maintenance of electrolyte balance in the gastrointestinal tract
- Regulation of fluid and electrolyte balance in the colon
- Regulation of blood flow in the skin for thermoregulation
- Maintenance of blood pressure in response to stress or dehydration
- Maintenance of body fluid pH during exercise and acid-base imbalances
- Regulation of blood sugar levels during fasting and feeding states
- Osmoregulation in freshwater and saltwater fish.