Understand How Homeostatic Mechanisms Operate in the Maintenance of an Internal Environment free essay sample

Change is detected by the receptors it can be any internal organ, then a message is sent to the brain which is the control centre then the effectors would react to get it back to normal. †¢Heart rate †¢Breathing rate †¢Body temperature †¢Blood glucose level Homeostatic control of heart rate Role internal receptors Internal receptors detect change in blood pressure. For example when doing exercise, our heart rate speeds up, the change is detected by the receptors that can be the internal organs which then send a message to the control centre, the brain and then it activates the effectors which bring the heart rate back to normal. The sinoatrial node (SA) is part of the heart, it is known as the pacemaker. The SA controls the rate of contraction. Autonomic nervous system The heart is controlled by the autonomic nervous system which is two branches called the sympathetic nerves system and the parasympathetic nervous system. We will write a custom essay sample on Understand How Homeostatic Mechanisms Operate in the Maintenance of an Internal Environment or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page The sympathetic nervous system is active when the body is undergoing muscular work such when we are doing exercise, like when running or jumping. It causes the increase in the heart rate and strengths the heartbeat. The parasympathetic nervous system calms the heart down and is active when the body is at rest. Heart rate is also increased by adrenaline. Adrenaline is a hormone from the adrenal gland and it is released duringwhen we are doing exercise, which increases the heart rate, this is the sympathetic nervous system is activated. Thermoreceptor detects a rise in body temperature and sends a message to the brain, then the hypothalamus to active the sympathetic nervous system, which increases the heart rate. Homeostatic control of breathing Rate Role of internal receptors Internal receptors measure the amount of carbon dioxide in the blood, and that information is relayed and processes by the medulla oblongata, which is the respiratory centre in the brain stem. There are chemoreceptors in the brain that sense the amount of oxygen, carbon dioxide and acid present in the body. As a result, they adapt the respiratory rate to properly balance for any disruption in balance of any of these chemicals. Too much carbon dioxide or acidity and too little oxygen cause the respiratory rate to increase. Carbon dioxide chemoreceptors are much more sensitive than oxygen chemoreceptors andsoapply an effect with smaller changes. Autonomic nervous system We don’t have to think about breathing because the autonomic nervous system controls it, as it does many other functions in your body. If you try to hold your breath, your body will overrule your action and force you to let out that breath and start breathing again. The respiratory centres that control your rate of breathing are in the brainstem or medulla. The sympathetic nervous system is active when our breathing rate is increasing for example when we are running or doing any exercise. The parasympathetic nervous system is active when our breathing rate is back to normal. The normal breathing rates for adult is about 20 breaths per minute. Respiratory centre, Diaphragm and Intercostals muscles Respiration is largely an involuntary act resulting from the automatic generation of rhythmic breathing by the respiratory centre in the brainstem. The rate of breathing is controlled by homeostatic mechanisms. The homeostatic control system includes receptors, the respiratory control centre and the effectors, the diaphragm and intercostal muscles. The diaphragm controls the flow of our breathing. The diaphragm main function it to helps inhale and exhale air from the lungs by contraction and expansion of the diaphragm. Intercostal muscles are muscle between two ribs in our chest. When we breathe in the ribs lift up and increase the volume of the rib cage. Homeostatic control of body temperature Producing body heat Heat is generated by the metabolic processes taking place in the body. Energy is released during chemical reaction and is usual used for muscle contractions but some of it is always released as heat. The liver is one of the main organs that help produce heat; some heat is also gained by hot food and drink and sometimes from the sun. The normal body temperature is 37 °C Loss of heat from the body When we feel hot we need to lose heat from the skin surface to cool our body down. There are four ways we can lose body heat from the skin: -Conduction- warming up anything that we are contact with such clothes even a pen would become warm from our hand when we are writing -Convection- is when we warm up the layer of air next to our skin and its moves up and is then replaced by colder air. It’s like having a fan next to you. Radiation is when the heat passes through your skin to warm up a colder object, such using your hand to warm up someone else because they have cold hands. -Evaporation of sweat – when we are hot, sweating will only cool the skin if it can take heat energy from the skin surface and convert into water steam and evaporate. Role of the hypothalamus The hy pothalamus is the processing centre in the brain that controls body temperature. It does this by triggering changes to effectors, such as sweat glands and muscles controlling body hair. Temperature receptors in the skin detect changes in the external temperature. They pass this information to the processing centre in the brain, called the hypothalamus. The processing centre automatically triggers changes to the effectors to ensure our body temperature remains constant, at 37 °C. The effectors are the sweat glands and muscle. Autonomic nervous system The parasympathetic nervous system hasnt got an important role in body temperature but it helps the unstraied muscle coats of the skin to reflex. The sympathetic nervous system controls the sweat glands and arterioles. The arteriole allows more heat to reach the surface of the skin. Effects of shivering Muscular activity helps generate heat so in a cold environmental we may rub our face, hands and d feet and also shiver. This is an effective way to generate heat. Implications of surface area to volume ratio in the care of babies Babies have a larger surface area volume ratio than adults and cannot effect change to gain heat or lose it. So they are at risk of developing hyperthermia is when the body temperature increasing above normal range or hypothermia is when the body temperature decrease above normal range. Homeostatic control of blood glucose Role of the pancreas, liver, insulin and glucagon Blood glucose is controlled by the pancreas and the liver; it also controls the insulin in the blood glucose. The pancreas role is converting the food we eat into fuel for the bodys cells. The pancreas has two main functions: an exocrine function that helps in digestion and an endocrine function that regulates blood glucose. The livers role is to convert the blood glucose into glycogen which is stored glucose. Insulin is a hormone. It makes our bodys cells absorb glucose from the blood. The glucose is stored in the liver and muscle as glycogen and stops the body from using fat as a source of energy.