“Physiological regulation of fluid compartment volumes and chemical composition is critical for normal cell function.”
It is important that the human body has the ability to maintain a constant internal environment referred to as homeostasis (Waugh and Grant 2010). Claude Bernard was a 19th century French physiologist who first discovered the concept of homeostasis. But it was Walter Cannon, a 20th century American physiologist who devised the word “homeostasis” (Marieb and Hoehn 2007). Temperature, pH, blood pressure, water and electrolyte concentration and blood glucose levels are the most important physiological variables maintained by homeostatic mechanisms (Waugh and Grant 2010).). Homeostasis is regulated by the nervous and endocrine system and there are three mechanisms involved in homeostatic regulation; receptor is the first mechanism involved. The role of the receptor is to monitor the environment and respond to any changes. If there is a change the receptor will send signals along the afferent pathway to the control center, the second mechanism involved in regulation. It is here that the control center establishes a set point at which the variable is to be maintained. One a set point is determined, the control center is able to send information along the efferent pathway to the third mechanism; effector which responds to the stimulus instructed by the control center. Feedback is either negative (opposing) or positive (enhancing) towards the stimulus. Thus, allowing the internal environment to return to a stable equilibrium. In most cases negative feedback is the homeostatic control mechanisms used. The response from the effector to the stimulus reduces or negates the intensity of the original stimuli (Marieb and Hoehn 2010). These homeostatic mechanisms allow homeostasis to gain control and maintain a stable state internally. Positive feedback mechanism is where the response from control center enhances the stimulus, to ensure the variable is back...
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