unit 5 P5- Explain the concept homeostasis with reference to the control of heart rate, breathing rate, body temperature and blood glucose. In this assignment I will be introducing a formal report that is based on an investigation into how the body responds to exercise and which analyses the results from the investigation. The investigation involves myself and other pupils in my class. I will be doing the Harvard step test. the other pupils in my class will be monitoring my heart rate, breathing rate and temperature before and after the test. The actual word homeostasis means "steady state". Homeostasis describes how the body regulates its process to keep its internal conditions as stable as possible. Homeostasis is necessary because human cells are efficient but very demanding. The phrase homeostasis is a bit confusing; conditions inside our bodies are not constant but are kept within a narrow range. some factors such as temperature and blood PH change slightly while others such as blood glucose very considerably throughout a normal day without producing any harmful effects. A brief description of homeostasis is that it is maintenance of a constant internal environment in response to a change in external environment. Negative feedback as a form of regulation
Negative feed makes sure that as levels return to normal, corrective mechanisms are scaled down. it's when the body maintains conditions within particular limits. the body will do this by opposing a change that deviates from the normal. core temperature falls.
Core temperature rises.
Drop detected by hypothalamus . brain sends signals to the body that brings out shivering and vasoconstriction. Temperature turns to normal.
Normal body temperature: 36.9c
Rise detected by hypothalamus. Brain sends signals to body that brings out sweating and vasodilatation.
Negative feedback comes when an important variable, sometimes known as a key variable such as the pH of blood and tissue fluid, deviates from the acceptable rang r limits, and triggers responses that return the variable to within the normal range. Basically deviation produces a negative response to counteract or nullify the deviation. it is a 'feeding back' of the disturbance to the status quo. due to the liver being part of the digestive system, as we know when blood glucose levels fall, the liver glycogen is converted into glucose in order to top up those crucial energy levels in cells. this is an example of a negative feedback system. The brain and nervous system play a vital role in controlling homeostatic mechanisms and they also help us to anticipate when key variables might rise or fall beyond the acceptable range. for example, if it is several hours since your last meal and you are beginning to feel tired and cold, you will try to eat a warm, energy-giving meal to counteract these feelings. this can be termed 'feed forward' (rather than feedback), as you are taking steps to avoid a low energy state before it has happened. Negative feedback systems require:
* receptors to detect change
* a control centre to receive the information and process the response * Effectors to reverse the change and re-established the original state.
blood glucose levels
The amount of glucose in your blood is carefully controlled. again, this used the hormonal system. The hormones responsible for regulating blood glucose are produced in the pancreas in particular areas call islets of Langertons. Roles of pancreas and liver
The pancreas is a small gland, located close to the stomach. the pancreas has two main functions, it contains clusters of cells that secrete the pancreatic endocrine hormones- insulin and glucagon into the blood stream in order to regulate blood glucose levels.
M2- Discuss the probable homeostatic responses to changes in the internal environment during exercise. "Homeostasis" means balance or equilibrium. How your body works to maintain equilibrium is reflected in how your...