Homeostasis: This is a self-regulating process which helps to maintain a constant internal environment despite external changes. The stability which is achieved is a dynamic equilibrium, which is a continuous change of occurrences. Majority of systems in the dynamic equilibrium will reach a balance, however when they are interrupted a built-in regulatory device will respond immediately so that it’s able to establish a new stable balance (also known as feedback control.) An example of homeostasis in a biological system is the control of body temperature in humans. Your body temperature is around 37 degrees Celsius, however many factors like hormones, metabolic rate and diseases can affect this value as they can lead to extremely high or low temperatures. Your temperature is controlled by a region of the brain called the hypothalamus; this response is carried through the bloodstream to the brain, resulting in adjustments to your breathing rate, levels of blood sugar and metabolic rate. Heat loss in humans is aided by a decrease of activity (known as perspiration) as well as by heat-exchanging mechanisms. Heat loss is reduced by insulation and cultural adjustments like clothing, shelter and external heat sources. My data
I have collected date of my own heart rate, breathing rate, temperature and blood pressure before and after 1 minute of running on a treadmill.
Measurement At rest After exercise After 1 minute interval After 2 minutes After 3 minutes
Pulse 86 109 94 91 92
Breathing 14 26 20 16 14
Blood pressure 90/51 148/80 133/72 100/53 104/70
Temperature 37 degrees 38 degrees 38 degrees 37 degrees 37degrees
Your pulse is the rate at which your heart beats; the average healthy pulse for individuals over 10 years is between 60 and 100 beats per minute. This table shows that my pulse rate when relaxing is at 86 which is between the average and at a healthy rate. When exercising the table shows how my heart rate increases by 23 beats per minute, this is quite dramatic however it is normal for your heart rate to increase when exercising. Once I finished running on the treadmill you can see that my pulse was slowly starting to decrease every time it was taken, this is due to my body cooling down and going back to its relaxed state.
Your breathing is to do with how many breaths you take per minute, though your breathing can be easily manipulated if you have to record your breathing rate for an experiment like the one I had to record on myself. My breathing when resting was 14 which is healthy for an individual of my age (17 years.) When exercising you can see that my breathing increased, this was to allow more oxygenated blood and nutrients get to my muscles to help them work harder and more efficiently for the kind of exercise I was doing, whilst in this state my digestive system slows down so that it doesn’t use up the energy that my muscles need. After a few minutes of exercising my breathing rate decreased back to its “relaxed” state as my body did not need the extra supply of energy to my muscles.
Blood pressure is the amount of pressure on your arteries every time your heart beats. The first number is the systolic pressure; this is the amount of pressure on the arteries from the blood. The second number is the diastolic pressure; this is the pressure on the arteries when the heart is not beating. When my body was relaxed my blood pressure was quite low. Throughout exercising my blood pressure increased dramatically and after exercising my blood pressure started to decrease steadily. My blood pressure was quite low when relaxing and after exercise, however this could be because I was on prescribed medications called PPI’s (proton pump inhibitors) and scopolamine butylbromide. Though this may not have affected my results, I have to consider the probabilities that it may.
The blood pressure scale for individuals:
• 90/60 or less: Means you potentially have low blood pressure;
• More than 90/60 and less than 120/80: Means your blood pressure is healthy;
• More than 120/80 and less than 140/90: Means you have a normal blood pressure though it is quite high, so some exercise or a healthy diet will help to lower this;
• 140/90 or higher (over a few weeks): Means you have high blood pressure, also known as hypertension;
• The top number is 140 or more – You potentially have high blood pressure;
• The bottom number is 90 or more – You potentially have high blood pressure;
• The top number is 90 or less – You potentially have low blood pressure;
• The bottom number is 60 or less – You potentially have low blood pressure.
My temperature when I was relaxed and after exercise stayed at 37 degrees. Though when exercising it rose to 38 degrees. This is due to the energy that is powering my muscles are lost as heat, causing my body temperature to rise during exercise.
Factors that may have affected my results could be down to being on medications that affect my digestive system as well as my cardiovascular system. The side effects are being that it can make you have a faster than normal heart rate (tachycardia), and potentially causing you to have a lower blood pressure (though this hasn’t been proven yet/ there are no resources that have enough evidence to prove so.) Another factors affecting my results could be to me recently starting smoking, this could cause my body to pump more blood around by body which will increase my heart rate, as well as making me taking more breathes.
The homeostasis response in my body was to ensure that my body converted food into energy during exercising, this so producing heat as waste product. The extra heat my body produced elevated my body temperature above 37 degrees. To maintain homeostasis my blood vessels had to dilate to allow more blood flow to the surface of my body where heat is then dispersed. During exercise my breathing rate increased so that more oxygen could be supplied to my skeletal muscles. This caused me to breathe more heavily even after I had completed my exercise. After I had finished running on the treadmill my body still needed larger amounts of oxygen to help break down the lactic acid build up in my muscles. During exercise my body produced more heat than usual as well as activating the heat exchanging process, though this easily went back to my normal temperature at 37 degrees. During the exercise my blood pressure increases in order to allow an efficient supply of nutrients and energy to my active muscles. Afterwards my body cooled down, though because I went straight to as seated recovery my blood pressure could have dropped abruptly which can have a negative effect on my body, considering I have low blood pressure.
The importance of homeostasis
Homeostasis is extremely important in maintaining a healthy functioning of the body as enzymes traveling throughout the body speed up chemical reactions, often known as catalysts. For these catalysts to work at their best, enzymes need to be in an environment which has a constant temperature to enable the body to function correctly and reduce denaturing. A healthy functioning human body would have a body temperature of 37 degrees Celsius, which is the best environment for your enzymes to function properly in. Therefore, when your temperature drops below 37 degrees your metabolic processes and reactions will become much slower as the molecules have less kinetic energy; in addition to this when your temperature goes above 37 degrees all enzymes will stop functioning and become denatured. This happens due to the ‘active site’ of the enzyme changing.
Blood vessels supply capillaries of the skin, which allows them to dilate (vasodilation), increasing the blood flow through the capillaries resulting in large quantities of energy to be lost. Heat stroke is mainly caused by an uncontrolled rise in body temperature as it increases blood to flow to the skins surface. Dehydration can occur due to excessively sweating, however when dehydrated you will sweat less which will increase your body temperature. Your normal mechanisms are then harmed and will not work properly. An opposite of this would be when you have a lower body temperature, leading to an increased rate of respiration stimulated by your muscles contracting quickly (shivering.) Blood vessels which supply capillaries will constrict (vasoconstriction); reducing blood flows well as energy loss. However, this could potentially result into hypothermia as the body’s core temperature is dropping below 35 degrees. Hypothermia is where the body is unable to replace body heat as fast as it’s being lost.
Your hormones are responsible for controlling blood glucose levels (produced in the pancreas.) When your blood glucose levels rise your pancreas detects it and will release a hormone called insulin. This binds to the receptor of the proteins in cell membranes within the liver and causes multiple protein channels to open up so that glucose is able to enter the cells. As a result, insulin within the liver will boost enzymes to change glucose to glycogen for storage in the liver cells, however if the levels decrease then the pancreas will release another hormone called glucagon which releases enzymes so that they’re able to break down glycogen to glucose, enabling blood glucose levels to return to normal.