Republic of the PhilippinesMALAYAN COLLEGES MINDANAOKm 2 MacArthur Highway, Davao CityIn Partial Fulfilment of the Requirements inGeneral BiologyHOMEOSTASIS AND FEEDBACK MECHANISMSSubmitted by:ANNALEE A. MACARAYASubmitted to:MA’AM ELENITA LAGANZONGeneral Biology 2 TeacherJanuary 6, 2020
HomeostasisHomeostasis, in a general sense, refers to stability, balance, or equilibrium.Physiologically, it is the body’s attempt to maintain a constant and balanced internalenvironment, which requires persistent monitoring and adjustments as conditionschange. Adjustment of physiological systems within the body is called homeostaticregulation. Homeostasis involves three parts or mechanisms: the receptor, controlcenter, and the effector (Lumen, 2019).The receptor receives information that something in the environment is changing.The control center or integration center receives and processes information from thereceptor. The effector responds to the commands of the control center by eitheropposing or enhancing the stimulus. This ongoing process continually works to restoreandmaintainhomeostasis.Forexample,duringbody temperature regulation,temperature receptors in the skin communicate information to the brain (the controlcenter) which signals the effectors: blood vessels and sweat glands in the skin. As theinternal and external environment of the body are constantly changing, adjustmentsmust be made continuously to stay at or near a specific value: the set point.Figure 1–Diagram of Negative feedback loop and body temperature regulation asa specific exampleAccording to Lumen (2019), the goal of homeostasis is the maintenance ofequilibrium around a specific value of some aspect of the body or its cells called a setpoint. While there are normal fluctuations from the set point, the body’s systems willusually attempt to go back to this point. A change in the internal or external environment
is called a stimulus and is detected by a receptor; the response of the system is toadjust the activities of the system so the value moves back toward the set point. Forinstance, if the body becomes too warm, adjustments are made to cool the animal. Ifglucose levels in the blood rise after a meal, adjustments are made to lower them and toget the nutrient into tissues that need it or to store it for later use.When a change occurs in an animal’s environment, an adjustment must be madeso that the internal environment of the body and cells remains stable. The receptor thatsenses the change in the environment is part of a feedback mechanism. The stimulus—temperature, glucose, or calcium levels—is detected by the receptor. The receptorsends information to a control center, often the brain, which relays appropriate signalsto an effector organ that is able to cause an appropriate change, either up or down,depending on the information the sensor was sending.