The Components Required for a Homeostatic Feedback Mechanism - Essay Example

? Homeostatis Homeostasis 1 Describe why the human body requires relatively stable internal conditions. Human body is a complex of many systems that work in coordination with each other in order to provide the body with its energy needs and other necessities to carry out bodily work. In order for these systems to work as required and perform their functions normally, specific and stable conditions inside the body are more than necessary. Every single system of the human body is composed of tissues which are then composed of cells. Cell being the basic structural and functional unit of the body works with other cells and provide the body what it needs. For a single cell to work, the conditions must be stable. For example, if the water content of the body is too high or low i.e. high or low osmotic pressure would make the cells either shrink or swell leading to cellular death and a vicious cycle leading to tissue destruction and so on. Similarly cellular enzymes require an optimum and stable pH for them to work and degrade food products to simple carbohydrates, fats and amino acids for the body to produce energy. These are just two of many examples of why the human body needs stable internal environment (Brodie, 2005). 2.1 Identify and describe the components required for a homeostatic feedback mechanism. As mentioned earlier, the human body is composed of many systems and these systems work in coordination with each other in order for it to work normally. These systems require stable internal conditions and whenever these internal conditions are disturbed; there is a feedback system which acts immediately to get this disturbed internal environment back to normal. This feedback system includes mainly of receptors in some areas which when sense in disturbance in the normal conditions activate immediately and send signal to the appropriate centres (Guyton, 2011). These signals could be transmitted through 1) Nerve cells e.g. vagus nerve sending signal to the brain and control heart rate 2) hormones e.g. renin which is released by kidneys either when there is a disturbance in the blood pressure due to water content of the body. Renin ten causes the formation of angiotensin 1 and 2 and control water content of urine. Hormones and nerve cells have a major role in this feedback mechanism. Hormones such as adrenaline, insulin, thyroxin and acetylcholine are some of the major hormones in homeostatic feedback mechanism in controlling heart rate, blood sugar levels, metabolism and many other functions. Nerve cells on the other hand provide feedback mechanism by transmitting signals directly to the brain which then transmits signals back by nerve cells again to appropriate centres or causes the release of hormones to bring the body back to stability. Nerve cells also act by sending signals to the endocrine or exocrine glands present at certain locations in the body and cause direct release of hormones or other secretions (Guyton, 2011). 3.1 Describe the mechanisms involved in body temperature regulation. Regulation of body temperature is one of the most important homeostatic functions of the body as all the bodily enzymes and other systems require an optimum temperature i.e.98.6f to work normally. This most important function is performed by the temperature regulation centre present in the Hypothalamus in the brain. Whenever an increase or decrease in the body temperature is detected by the receptors present in peripheral regions of the body, immediate signals are transmitted to the hypothalamus which then sends signals to all the parts of the body for its regulations. In case of an increased internal temperature the hypothalamus sends signals to the peripheral blood vessels located mainly in the skin which dilate causing more blood to flow through them leading to heat loss and decreased metabolism to decrease heat production. Also, there is immediate activation of sweat glands located in the skin and excessive production of sweat causes loss of heat through evaporation causing the body to cool. Whereas in case of increase in the internal temperature, the vessels are constricted to restrict the blood flow so that more heat is restrained inside the body. There is activation of piloerector muscles present in the skin which causes the air to trap in the hair present in the skin which acts as an insulator and restrains heat inside the body and metabolism is increased (Ganong, 2005). 4.1. Describe how blood sugar is regulated in the human body. Glucose is one of the main energy sources of the body. For glucose to produce energy to be consumed by the body, it must be regulated within the normal values so that it could enter the cells in sufficient amounts and be converted into energy. The normal blood glucose levels are 4-9 mml/l. whenever there is an increase in the levels i.e. more than normal; the body produces hormones such as insulin which cause the activation of cellular channels for transport of glucose across cell membrane leading to an increase in the uptake of glucose by cells. In case of a deficiency or total lack of insulin excessive glucose or some of excessive amount is converted into ketone bodies and excreted out in the urine as is shown in the case of the patient. When there was an increase in blood glucose levels to 35mml/l, ketone bodies were observed in the urine while they were totally absent when glucose levels were back to normal. In case of a decrease in blood glucose levels, Glycogen is released to bring it back to normal which is an exact opposite of insulin (Ganong, 2005). 5.1 Describe how the body is able to regulate water balance by the production of dilute and concentrated urine. Renin Angiotensin system is the main regulatory system which acts directly on the kidneys to regulate body’s water content by concentrating or diluting the urine. Whenever there is a decrease in the arterial blood pressure signalling hypovolemia i.e. a decrease in body’s water content, the body acts immediately by releasing rennin from kidneys. Rennin causes the activation of angiotensinogen to angiotensin 1 and then 2. Angiotensin 2 then acts directly on the kidneys to prevent further water excretion. Also, it causes the release of aldosterone which acts on the renal tubules to bring NaCl back from the distal tubules creating enough osmotic difference for the transport of water back to the body thus retaining it inside the body. In case of increased water content, the body produces diuretic hormones such as ADH which produce diluted urine, excreting excessive water out of the body (McFarlane. 2006) References. BRODIE, M. E., & RICHARDSON, M. (2005). Homeostasis. Hatfield, University of Hertfordshire Press. GANONG, W. F. (2005). Review of medical physiology. New York, McGraw-Hill Medical. HALL, J. E., & GUYTON, A. C. (2011). Guyton and Hall textbook of medical physiology. Philadelphia, Pa, Saunders/Elsevier. MACFARLANE, M. T. (2006). Urology. Philadelphia, Lippincott Williams & Wilkins. Read More