Homeostasis is the ability to maintain a constant internal environment in response to environment changes. However both the nervous system and also the endocrine system control homeostasis in the body through feedback mechanisms which involves various organs and organ systems. Some examples of this are body temperature, pH balance, water, electrolyte balance, respiration and also blood pressure. The internal environment is the conditions inside the body; homeostasis aim is to maintain this at a constant level. Each process has a desirable peak environment which is called the norm, influences such as the external environment can cause deviation away from its norm level and the body will do this through negative feedback. Negative feedback in homeostasis describes the process by which bodily systems maintain their normal environment or states. Homeostasis describes the body’s overall regulation of its internal system. However when it changes for example body temperature negative feedback responses are triggered to then be able to bring the temperature back to its normal point. For example if the body becomes too hot sweating will occur to try and cool the body down, and if the body became too cold shivering would occur to warm the body back up . The typical state of a bodily system is called the set point; however negative feedback in homeostasis can’t keep systems exactly at the set point. Therefore negative feedback in homeostasis acts to keep body temperature within a normal range of values. However the value of a system that changes due to different circumstances is called a variable. Within negative feedback there are three different parts these are: the receptor, control centre and the effector. The receptors job is to detect changes in the value of the variable, then the information is passed along to the control centre which the monitors the changes and begins a negative feedback response when the changes fall too far outside of the normal range of values. Therefore when that has occurred the control centre will then trigger the effector to take action that will help return the system towards its set point. Homeostasis is important for the cells because all living cells depend on the movement of chemicals around the body. For example oxygen and carbon dioxide are dissolved into food to then be transported into and out of cells. This process is called diffusion and also osmosis, however these processes all depend on the body’s water and salt balance and these are maintained by homeostasis. Cells also depend on enzymes to speed up the chemical reactions to keep the cell alive and to make it do its role. The enzymes work best at a typical temperature, homeostasis is vital for this as it maintains a constant body temperature.
The effect exercise has on someone’s breathing rate is the pulse becomes faster, quicker breathes and also longer breathes. Exercise increases the rate at which energy is needed from food; therefore this then increases the need for food and oxygen within the body. This is why breathing rate is increased in exercise. Breathing rate is controlled by nerve impulses from the brain; negative feedback changes the rhythm, depth and rate of breathing when receptors in the blood detect changes in the amount of carbon dioxide in the body. However when blood carbon dioxide levels are high the receptors will be able to pick this change up and report it back to the brain which then sends signals to quicken and also deepen the person’s breathing rate so they breath out more carbon dioxide. Breathing rate increases to be able to get more oxygen into the lungs so that the lungs can pump more oxygen into your blood and out to your muscles and to also get rid of carbon dioxide. Muscles within the body quickly deplete stored energy when you start exercising, to be able to make more energy muscles combine oxygen with ATP. This process creates heat energy as a by-product; extra heat will then raise your body temperature so your body will need to eliminate heat as quickly as possible. Therefore temperature sensors will tell the hypothalamus that the body temperature is increasing rapidly. During exercise extra blood flows to the muscles to be able to keep them going. However when body temperature starts to increase, extra blood flows to your skin so evaporation or sweat can help you cool down. Blood flow diverted from other organs for example the kidneys and liver allows more blood to flow to your skin surface. However some extra heat it caused by circulatory system but this is eliminated by respiration as you breathe out heated air. Body temperature is also controlled by negative feedback which changes the temperature and the right action is taken to keep the body’s core temperature constant. This is very important to prevent the body’s vital organs from overheating, this body will respond to hot conditions by losing heat to keep the core cool and also cold conditions by retaining heat to keep the core warm. This is a result from homeostasis.
Pulse rate is increased with exercise this is because the heart rate increases to be able to supply the muscles with more oxygen to be able to produce extra energy that is needed. To be able to control this rate the brain sends signals to the heart; however the body also produces chemical hormones for example adrenaline which can change the heart rate. Pulse rate increases to be able to get extra food and oxygen to the muscles. Heart muscles organise the sequence of its own contraction. These two groups of cells are in the medulla at the base of the brain control heart rate. These centres are: cardioacceletory centre which raises the heart rate, and cardioinhibitory which lowers the heart rate. However both of these are connected to the sinoatrial node and also the atrioventricular node in the heart by nerves from the autonomic nervous system. To be able to lower heart rate impulses from the cardioinhibitory system passes down the vagus nerve to the heart. At the atrioventricular and sinoatrial nodes the nerve secretes a chemical which is called acetycholine which then acts on the nerve cells in the heart nodes. It inhibits the nodes so that fewer impulses are produced and the heart beats slower. To be able to rise heart rate impulses from the cardioacceleatory system pass down a different autonomic nerve to the heart. At the sinoatrial and also the atrioventricular nodes the nerve will secrete a chemical which is called noradrenaline which acts on the nerve cells within the heart nodes. This chemical increases the rate which the nodes produce impulses and the heart rate increase. This is controlled by homeostasis.
Homeostasis is very important within the body because it controls everything within the body. If we didn’t have homeostasis our body functions would not work properly and we would gain many complications without this, for example homeostasis maintains body temperature therefore if we didn’t have this we would get too cold or even too warm and vital organs would be affected and then starts to die off. If our body didn’t maintain homeostasis we would eventually die, this is because we need homeostasis to be able to maintain vital levels within the body to keep us alive. Blood glucose is needed for cells for respiration, It is important that the concentration of glucose in the blood is maintained at a constant level. A hormone that is produced by the pancreas is called insulin this then regulates glucose levels within the blood. If glucose levels are too high insulin is then secreted into the blood and then the liver will convert glucose into glycogen and then the effect of glucose levels go down. However if glucose levels goes too low the insulin is not secreted into the blood and then the liver does not convert glucose into glycogen and then the glucose levels goes up. The pancreas realises another hormone called glucagon this is when the blood sugar levels fall. This then causes the cells in the liver to turn glycogen back into glucose which can then be released into the blood, blood sugar levels will then rise back up. Blood glucose levels should be roughly be between 4-6. Therefore the homeostasis of glucose is essential for insuring health and the reduction of symptoms. An increase in carbon dioxide concentration leads to a significant increase in breathing rate. An increase in H+ leads to an increased rate of breathing, however together CO2 and H+ stimulated receptors which are located in the respiratory centre in major arteries the carotid and the aorta. Receptors that are stimulated by chemicals like CO2 or H+ are called chemoreceptors. Oxygen is continuously used by cells, so its concentration in the blood decreases. However in contrast to carbon dioxide oxygen concentration needs to fall significantly before any increase in breathing rate result. However chemoreceptors that detect oxygen concentrations are located in the walls of two major arteries which are the carotid and aorta. These cells are known as aortic and carotid bodies. However when these cells detect a decrease in concentration, nerves impulses are sent to the respiratory centre, therefore the impulses are sent to the respiratory muscle to stimulate the breathing process. Homeostasis regulates heart rate and internal functions to maintain equilibrium; homeostasis uses negative and positive feedback system to keep the human body running efficiently. When you stop exercising or decrease the level of activity the muscles within the body send another message to the medulla to be able to release acetylcholine. This hormone slows down the concentrations of the heart and then allows the heart to rest by reducing heart rate. The hypothalamus is the temperature regulating centre of the brain; it contains receptors which are sensitive to the temperature of the blood flowing through the brain. Temperature sensitive receptors in the skin also feedback information to the hypothalamus about the temperature of the skin surface. Therefore changes in core body temperatures cause the hypothalamus to send nerve impulses to the sweat glands, muscles and blood vessels to raise or lower the body temperature. However if core body temperature goes up the body loses heat to bring it back down again, if core temperature goes down the body will conserve and even generate heat to bring it back up again. The summary of this is that if we didn’t have any of these functions we would die off this is because these functions are vital to keep the body going and to be able to maintain the vital organs that are needed to stay alive and to also keep healthy.