Definition of Anatomy, Physiology, Various Suffix, Prefix used in Anatomy and Physiology

Homeostasis:

Homeostasis is the regulation and control of many bodily systems and physiological processes to maintain consistent conditions in the internal environment. Although the word's literal meaning is "Unchanging," it actually refers to a dynamic, constantly-changing scenario that is managed within specific bounds. The internal environment of a healthy organism remains the same within its usual boundaries even when the exterior world changes continually. However, internal circumstances change within a certain range; for example, body temperature might vary from 36°C to 37°C (97°F or 99°F).

Feedback Mechanism:

Numerous feedback mechanisms (control systems) that are able to recognize and react to changes in the internal environment maintain homeostasis. A feedback system is a series of actions in which the condition of the body is tracked, adjusted, and tracked again, etc. Three fundamental detectors (receptor, control center, and effecter) make up a feedback system.

The feedback system establishes the parameters that should be maintained for the variable factor. It receives a signal from a detector or sensor and incorporates the data that comes in. The control center reacts and modifies its output to the effectors when the incoming signals suggest that an adjustment is required. This dynamic process enables continuous readingjustment of a number of physiological variables.

Such physiological variables are:

• Core body temperature
• Water and electrolyte concentration
• PH (acidity or alkalinity) of body fluid
• Blood glucose level
• Blood and tissue oxygen and carbon dioxide level
• Blood pressure

A feedback system can respond to a condition by providing either positive or negative feedback.

• Negative Feedback Mechanism:
  • Negative feedback is the primary process that maintains a variable close to its set point. It starts an impulse that prevents the occurrence of additional of the same reaction. The body detects changes in systems regulated by negative feedback and activates mechanisms that lessen, reverse, or nullify the consequences of the original stimulus, preserving or restoring homeostasis. Blood pressure, heart rate, and body temperature regulation all rely on negative feedback mechanisms.
  •  Conditions in the body (Physiological variable change from set point)→  Change detected→ Corrective mechanism activated→ Conditions returned to set point→ Corrective mechanism switched off
  • By using a house heating system as an example, these concepts can be better comprehended. Changes in the ambient temperature can be detected by the thermostat (temperature detector) (variable factor). The boiler is linked to the thermostat (effector). The thermostat continuously checks data from the detector with the predetermined temperature, and when the difference is low, it turns on the boiler. As a result, the boiler releases heat, warming the space. The system is switched back on when the temperature reaches the preset point. Similar to this, the boiler shuts off when the thermostat notices a higher room temperature. It is a negative feedback mechanism that has led to these events. Similar to this, in the human body, when the body temperature drops below 37°C (the current level), this is sensed by particular temperature sensitive nerve endings in the hypothalamus of the brain (the control center), which then initiates a system that raises the body temperature (effectors). One of these causes shivering is the activation of skeletal muscles. Skin blood artery narrowing lessens blood flow to and heat loss from the margins. Changing one's behavior, such as covering up more or curling up, can also stop heat loss.
  • Signals to the hypothalamus cease when the body temperature rises back to within the normal range because the temperature-sensitive nerve endings are no longer stimulated. Shivering stops as a result, and peripheral blood flow returns to normal.
• Positive Feedback mechanism:
  • A physiological change causes much greater alterations in the same direction when there is positive feedback, as opposed to the corrective consequences, which would otherwise occur. In a positive feedback mechanism, the stimulus gradually raises the response, causing the response to rise over time as long as the stimulus persists. Even while positive feedback can be savage at times, the body's regulation system for negative feedback is able to counteract it. It could be dangerous and beneficial. Blood clotting and uterine contractions during labor are two good examples. The baby's head presses against the cervix during labor, stimulating the nerve endings there. Nerve signals are sent to the brain which stimulates the pituitary gland to secrete the hormone oxytocin further strengthening the contraction and maintaining labour until the baby is born. After the baby is born the stimulus (stretching of the cervix) is no longer present, so the release of oxytocin stops.

Homeostatic Imbalances:

The body's cells work well to maintain homeostasis through a negative and positive feedback mechanism as long as all of the body's controlled conditions stay within a set of strict boundaries. This keeps the body healthy. When the body is unable to keep a balance (moderate imbalance), illness or disease may develop, and if the imbalance is extreme, it may even lead to death.