Homeostasis and Feedback

The Physics and Chemistry of Homeostasis [image003.gif] Melanie Harris Homeostasis and Feedback A) Homeostasis is the maintenance of a stable internal environment within tolerance limits this is the restricted range of conditions where cellular operations are able to work at a consistent rate and maintain life. Homeostasis also adjusts to the changing circumstances of the external environment, e.g. a cold climate. Homeostasis is a self-adjusting system (auto-regulation), which involves biological feedback. Feedback is the general workings of nervous or hormonal regulation within the body. Homeostasis must maintain cells, tissues and the body in a state of equilibrium in order for life to be sustained. The human body has particular physical features such as the skin and circulatory system, which help its survival the environment. The metabolism is able to adjust to changes in conditions both internally and externally, as they are experienced. Biological Feedback Negative feedback: when the response reduces the original stimulus. . Negative is the most common feedback in biological systems. '. Blood glucose concentrations rise after a sugary meal (the stimulus) '. The hormone insulin is released '. This speeds up the transport of glucose from the blood '. And into selected tissues (the response) Blood glucose concentrations

  • Word count: 2061
  • Level: AS and A Level
  • Subject: Science
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The mechanism of Negative feedback.

Biology Essay-The mechanism of Negative feedback Homeostastis means bhattified sex. is an ability of an orgasmn to control its internal environment, that is the composition of their body fluids, for them to survive fluctuating external conditions. Homeostasis is used to describe all the mechanisms by homeostatic control. Maintenance of stability requires control systems capable of detecting any deviation from the usual and making the necessary adjustments to return it to its normal condition. The internal environment can by controlled by hormones. Hormones are chemical substances secreted into bloodstream by glands of the endocrine system. In humans, more than a dozen tissues and organs produce hormones. Some, including the pituitary, the thyroid, the parathyroid glands and adrenal glands are endocrine specialists; their function is to secrete one or more hormones. The endocrine system maintains homeostasis, the balance of the body, by making sure the concentration of many different substances in body fluids are kept at correct level. Controls of blood sugar level, blood pH and water balance are all examples of homeostasis. Homeostasis is a characteristic of living things. Term is used for any system, biological or non-biological, which is in a steady state. Whenever a physiological factor changes, the body will detect the change and by either using hormonal or

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  • Level: AS and A Level
  • Subject: Science
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DEFINE THE TERM HOMEOSTASIS AND USING EXAPMLES FROM A NAMED SPECIES, EXPLAIN HOW FEEDBACK MECHANISMS FUNCTION IN MAINTAINING HOMEOSTASIS

DEFINE THE TERM HOMEOSTASIS AND USING EXAMPLES FROM A NAMED SPECIES, EXPLAIN HOW FEEDBACK MECHANISMS FUNCTION IN MAINTAINING HOMEOSTASIS. INDEX . INTRODUCTION 2. DEFINITION OF HOMEOSTASIS 3. FEEDBACK MECHANISMS 4. THERMOREGULATION IN THE HUMAN BODY 5. CONCLUSION 6. REFERENCE LIST . Introduction Homeostasis is one of the essential features of living beings. It is the maintenance of the internal environment within tolerable limits. The study of Homeostasis reveals that the balance between a living organism's internal condition and the external environment needs to be achieved in order to acquire a dynamic equilibrium. The first part of this essay would include a clear definition of the term Homeostasis, its historical background, and a definition of internal environment. The second part will start with a description of Feedback mechanisms and its basic components, followed by a definition of positive and negative feedback. It will also illustrate how the human body deals with thermoregulation in high and low temperature situations in order to maintain a control fluctuation of temperature. 2. Definition and Principles The word Homeostasis comes from the Greek roots homeo and stasis meaning to remain the same. According to Tortora & Grabowski (1996) Homeostasis is a condition in which a body's internal environment remains within certain physiological limits.

  • Word count: 1192
  • Level: University Degree
  • Subject: Physical Sciences
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PROVIDING NEGATIVE FEEDBACK

MAP 556 HOMEWORK PROJECT PROVIDING NEGATIVE FEEDBACK HUONG DIEU DANG MBA CLASS - COHORT 1 As a banking official of the Bank for Foreign Trade of Vietnam (Vietcombank), I have to supervise interns and colleagues who are on probation. According to the bank's policy, I am asked to give them feedback at the end of the year. However, in response to your request for this assignment, I decided to provide my objective comments over phone to Mr. To, who was an intern and have been on probation at Vietcombank since the beginning of 2004. Through this experience, I recognize the importance of how to give an effective feedback. As I left Vietcombank, Hanoi for the Eller College of Management, Arizona at the end of this July, my feedback just covers the first seven months of 2004. A written copy of my feedback will be sent to the bank later. Based on Mr. To's performance at the bank's Marketing Division during that time, my comments to him are divided into four areas: communication skills, understanding of job, technical understanding, and potential for advancement. Communication skills Mr. To demonstrated good communication skills while performing his duties within the marketing division. His ability to listen to the bank's new clients (small and medium enterprises- SMEs) and convey to his colleagues clients' needs for financial funding was demonstrated in the successful

  • Word count: 1631
  • Level: University Degree
  • Subject: Business and Administrative studies
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Control of homeostasis.

HOMEOSTASIS According to totora .......... Homeostasis can be defined as " the condition in which the body's internal environment remains constant, within physiological limits". Homeostasis is a dynamic condition as the body's equilibrium point can change over a narrow range that is compatible with maintaining life. E.g., the level of glucose in the blood does not normally fall below 70mg of glucose per 100ml of blood. Each body structure helps to contribute to keep the internal environment within its normal limits. For example, if the level of blood glucose within the drops then the body compensates it by using fats stores as a reserve supply of glucose Body fluids An important aspect of homeostasis is maintaining the volume and composition of body fluid. The fluid within cells is called intracellular fluid (ICF). The fluid outside the body cell is called extracelluar fluid (ECF). Dissolved in the ICF and ECF are substances needed to maintain life such as O2, nutrients, proteins and electrally charged ions. Bernard predicted - the proper functioning of the body depends on precise regulation of the composition of the surrounding fluids of cells, known as interstitial fluid (internal environment). The composition of interstitial fluid changes as substances move in and out of the cell. For example, there is an exchange of materials across the capillary walls. This

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  • Level: AS and A Level
  • Subject: Science
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What is Homeostasis?

Homeostasis Homeostasis works to maintain the organism's internal environment, where the body's processes are able to function at a level that would allow life to continue in that organism. The three systems which are controlled by homeostasis are the respiratory, cardiovascular, and muscular systems. Changes to the cardiovascular system are often a result of changes in the activities of other systems. The heart rate, the cardiac output and the blood pressure change to different degrees of bodily activity. The heart rate slows and cardiac output falls when demands on bodily systems are less high. However the opposite is true when demands on the bodily systems are high, the heart rate increases and also the cardiac output also increases. Breathing is essential to life: it allows oxygen to be taken in and carbon dioxide to be given off. Processing food in order to obtain the energy needed for a wide range of activities is dependent on a continuous supply of oxygen to the cells. The respiratory system takes in oxygen and excretes carbon dioxide. Homeostasis allows the respiratory system to take in oxygen in many different situations where the breathing rate is irregular. Muscular activity requires a source of energy. When muscles are working aerobically, three main products are created: heat, carbon dioxide, and water. The heat produced by active muscles helps to maintain

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  • Level: AS and A Level
  • Subject: ICT
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Homeostasis & Control of BGL.

Homeostasis & Control of BGL Homeostasis Source - www.bbc.co.uk/schools/gcsebitesize/biology/humans/homeostasisrev1.shtml All the cells in our bodies are surrounded by a liquid called tissue fluid which has exactly the right conditions in which cells can work. Tissue fluid has the right temperature, the right amount of glucose and the right amounts of water and salt. Homeostasis is an important process that maintains these conditions at the right level. Source - http://pespmc1.vub.ac.be/ASC/HOMEOSTASIS.html A process of interaction which balances various influences and effects so that a stable state or a stable behaviour is maintained. Often that stable state or that stable behaviour is essential to assume structural stability of a SYSTEM. E.g., the size of the pupil of the human eye is negatively correlated with the intensity of light entering the retina thus keeping the amount of light within the limits of optimal processing of visual information. Too much light will destroy the light sensitive cones of the retina. The blood sugar content and many other chemical quantities are similarly balanced within the human body. In families, homeostasis may become pathological when family members no longer prefer that state yet cannot escape it as a consequence of the way they interact with one another (e.g., double bind). Source - http://pespmc1.vub.ac.be/HOMEOSTA.html

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  • Level: AS and A Level
  • Subject: Science
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Whats involved in Homeostasis.

Homeostasis Homeostasis involves various processes to keep the conditions inside the body constant. This allows conditions outside the body to change and have no immediate effect on the body. This needs to happen so that biochemical reactions inside the body can continue. The enzymes involved in these reactions are sensitive to changes in temperature and pH. If the environment is not kept constant these enzymes may denature. A constant water potential also needs to be kept so that osmosis can occur, supplying surrounding cells with their fluid. Homeostatic systems are used to decrease the impact of fluctuating conditions outside the body. To do this several organs must be co-ordinated so that the relevant information can be sent to and from the brain. Homeostasis is usually achieved by a process called negative feedback. This is how receptors in the body detect a change in the level of an interior factor. This then activates effectors to restore the body to the optimum level. We know that temperature and pH have 2 be kept constant, but the following features of the blood and tissue fluid also need to be kept within limits: * Concentration of important ions such as potassium and calcium * The Glucose concentration * Water Potential The Glucose concentration in the blood needs to be monitored closely because certain parts of the body can't store carbohydrates. So when

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  • Level: AS and A Level
  • Subject: Science
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What is Homeostasis?

HOMEOSTATSIS Homeostasis is a very important biological function that occurs in all endotherms but not ectotherms. Endotherms have the ability to adjust their body temperature: they are not dependent on the surrounding temperature of the environment. Examples of endotherms are mammals: humans. Homeostasis works by using a process called negative feedback which works by adjusting a condition in the body so that the internal environment stays, on average, the same. It works using nerves. A receptor detects the change in the surrounding environment and sends nerve impulses to the centres in the brain, such as the medulla, which sends nerve impulses to glands or muscles to bring about an effect which will lower or increase a condition in the internal environment to keep it within certain limits. Homeostasis is used to control body temperature, blood glucose concentration and the water content of the blood. The body temperature in endotherms is controlled by dilation and contraction of arterioles, sweat and contraction of the erector pili muscles. This is called thermoregulation. When the temperature of the surrounding environment increases the internal environment must be decreased. To do this the arterioles dilate (vasodilation) so that more blood flows through the capillaries next to the skins surface. This means more heat can be released through the skin as the blood is

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  • Level: AS and A Level
  • Subject: Science
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Which is more effective at improving performance, positive or negative feedback?

Which is more effective at improving performance, positive or negative feedback? The aim of this investigation is to discover which form of feedback, either positive or negative, is most effective in serving to improve performance. Based on my own experience and anecdotal evidence, my initial opinion is that positive feedback is more effective at improving performance than negative. Feedback Feedback is essential in order to reassure performers that what they are doing is correct so it will be repeated, or telling them what they are doing wrong so they can improve. There are several types of feedback that can be used, the most appropriate methods to be used vary between individuals and sports. The different types are; * Positive & Negative * Intrinsic & Extrinsic * Terminal & Concurrent * Knowledge of results & knowledge of performance Positive This is essential for learning as we need to know what is correct in order to repeat it. If positive feedback is not given, performers are likely to change their technique until told it is correct. Positive feedback is also motivational, which is essential at early stages as beginners may be less enthusiastic and can become de-motivated when struggling. Negative This form of feedback must be used cautiously, as too much can prove de-motivating and lead to a decline in performance, as well as commenting on what areas of

  • Word count: 1242
  • Level: AS and A Level
  • Subject: Physical Education (Sport & Coaching)
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