The Mechanism And Methods Of Homeostasis

I like to talk to you about a process that helps us maintain out body temperature called homeostasis. This is one of the body’s most important assets, because without it we wouldn’t be able to adjust to the changing environment outside of our bodies. It is a fight between the outside forces that bully our internal environment and the system that fights against this attack, and usually homeostasis makes sure the conditions are within a range the body can handle. Negative feedback, one of the most used methods of homeostasis, is a way of regulating where the same processes give us the same results (Simon, Dickey, Hogan & Reece, 2019). A great example of this is when you use the bathroom and flush the toilet, the water rises in the tank, the water lifts up the float, and the float stops the water from overflowing in the tank. The less popular option used in homeostasis would be positive feedback, which is the result of a process that intensifies the same process (Simon, Dickey, Hogan & Reece, 2019). This sounds a little extreme but think about it like this, when we get a broken blood vessel, proteins found in the blood are activated and form a small blood clot, the proteins continue to produce more until the clot is large enough to seal off the blood vessel.

In order to function properly, the body has to maintain a certain temperature, this is where thermoregulation comes in. Thermoregulation manages the temperature of the body, using different types of approaches, let’s talk about them. The first one is Ectotherms, who get their body heat from their environment, these are reptiles not including birds, fish, amphibians, and most invertebrates and the second is endotherms, who get their heat from their metabolism, and are always slightly warmer than their surroundings (Simon, Dickey, Hogan & Reece, 2019). When you really think about it, there are plenty of structures and mechanisms that help with thermoregulation, like a control center located in the brain that is programmed to keep the body at 98. 6 degrees, or how our blood vessels tighten towards the surface of our skin when we’re cold while our muscles tighten themselves to help produce more heat (Simon, Dickey, Hogan & Reece, 2019). The reason muscles can create heat is because all cells can due to cellular respiration. Anyway, when the body gets too hot, the control center tells the blood vessels to widen near the skins surface and trigger the sweat glands so the heat can escape (Simon, Dickey, Hogan & Reece, 2019).

An alternative way of controlling body temperature is through fevers, usually fevers are seen as bad, but things aren’t always what they appear to be, sometimes a fever can alert us about an oncoming illness. When the immune system comes in contact with an invader, chemicals are released by cells that travel through the bloodstream to the brain, these chemicals that go to the brain are meant to raise the temperature and are the cause of a fever (Simon, Dickey, Hogan & Reece, 2019). A moderate fever can be helpful in keeping the internal defenses quick and bacterial growth low, but anything above 104 degrees Fahrenheit is deadly and can cause damage to the body’s protein (Simon, Dickey, Hogan & Reece, 2019). We should all know that the main cells rely on water and solutes, so no matter where an animal is if it digests too much water or doesn’t get enough eater, it will die. The reason we would die from having an abundance of water in our body is because this would cause the cells to swell up an explode, while having none at all would make the shrivel up (Simon, Dickey, Hogan & Reece, 2019). By using osmoregulation, the body can control the gain or loss of water and solutes, like the ions of NaCl and other salts, since water follows the movements of solutes through osmosis (Simon, Dickey, Hogan & Reece, 2019). Osmosis occurs only when two solutions separated by a cell's permeable membrane are different from the total solute concentrations (Simon, Dickey, Hogan & Reece, 2019). This technique will always involve the movement of water from solutions with the lowest concentration to those with a higher one. Imagine saltwater fish, these fish lose water though osmosis since their tissue contains less salt than the water where they live, this is reversed for freshwater fish because water enters through osmosis since the level of solute is low.

This being said, all beings are open systems, we eat, breath, sweat, pee, and make heat, which simply means that we recycle chemicals and energy for the environment around us (Simon, Dickey, Hogan & Reece, 2019). The way an animal looks does affect the way it experiences the world. Simple cells need to trade resources directly, while more complex organisms can indirectly trade, thanks to the circulatory system with internal structures and the environment (Simon, Dickey, Hogan & Reece, 2019). Unfortunately, since most land animals lose most of their water through urination, sweating, pooping, and breathing, the only way to counter this is by eating and drinking, sadly we are always in danger of dehydration (Nguyen, 2018). I'm sure we've all seen the different colors of our pee, this is a way to tell how hydrated we are, if the urine is pure yellow, the body is storing the all water we have in our body, if it is diluted and clear, the water is being released (Simon, Dickey, Hogan & Reece, 2019). The urinary system actually has a lot to do with osmoregulation since it keeps a certain amount of water and soluble in the body, the way is does this is by hiding the water when we are dehydrated and getting rid of it when we are hydrated (Simon, Dickey, Hogan & Reece, 2019).

This system is mandatory, and connected to all the bodies systems, since all animal cells need water balance and waste removal (Simon, Dickey, Hogan & Reece, 2019). In order to survive organisms, rely on all organ systems, and everything you do has an effect on your body, whether it is positive or negative. So, for those of you who skip meals frequently, you are lowering your blood glucose level and causing pancreatic cells in the endocrine system to release glucagon into the liver so that is can put glucose into the bloodstream to increase your glucose levels (Simon, Dickey, Hogan & Reece, 2019). If your organs aren’t working properly, then you’re in big trouble. One of the most important organs in the urinary system is the kidneys, they are the size of a bean and found on both sides of the abdomen and consists of 100 thin tubes known as tubules and a network of small blood vessels (Simon, Dickey, Hogan & Reece, 2019). Blood travels through the kidneys daily, and once the plasma enter the tubules it is called filtrate, which also contains material the body needs along with waste. The kidneys job is to filter nutrients back to the blood, and without them you wouldn’t last 2 days (Simon, Dickey, Hogan & Reece, 2019).

Blood enters the kidney through the renal artery to be filtered, and leaves through the renal vein, on the inside of the renal artery turns into millions of minuscule blood vessels, and one of these branches gives it to a nephron (Simon, Dickey, Hogan & Reece, 2019). There are plenty of nephrons in kidneys, this is because they control the functions of the urinary system. What happens is the pressure from the blood forces water and solutes in the blood into a filter found in the nephron tubule, this is what is called a filtrate and it goes throughout the tube to absorb water and nutrients back into the blood while it leaves the waste behind (Simon, Dickey, Hogan & Reece, 2019). Once this waste has a strong concentration it leaved the body through the urethra, which is in the urinary bladder. I feel like I left out something really important, I don’t think I mentioned hormones. In the body there is a certain hormone that controls the nephron found in the kidneys to manage water balance, these same hormones are linked to the urinary, endocrine, and nervous system (Simon, Dickey, Hogan & Reece, 2019). I’ll try to explain this the best way I know how. When a solute concentration becomes too much for the body to handle, the brain tells the endocrine’s pituitary gland to let larger amounts of ADH, antidiuretic hormone, into the blood, once it reaches the kidneys it creates nephrons to absorb water from the filtrate (Simon, Dickey, Hogan & Reece, 2019). This brings up the water levels in the body and makes the urine more concentrated.

When there is a large amount of water in the body, the levels of ADH lower and the kidneys take in less amounts of water which is why when we urinate it looks watery. This doesn’t happen with alcohol or caffeine, they both prevent the release of ADH and actually cause us to lose a lot of water (Simon, Dickey, Hogan & Reece, 2019). This explains the “hangover” we get when we drink a lot, it is just another case of dehydration. When you understand how filtration, reabsorption, and secretion work, then you know why urine is used as a health indicator (Simon, Dickey, Hogan & Reece, 2019). Diabetic often have traces of glucose found in their urine, since the excess glucose if not being absorbed by their body, while you can tell someone is pregnant by a certain hormone found in their urine (Nguyen, 2018). We all know urine test are commonly used to drug test for jobs, and to look for STDs. Sure, we can check blood for these too, but it’s not as accessible. This doesn’t mean everybody has the same type of urine, environment, disease, and diets are some of the things that affects its structure (Simon, Dickey, Hogan & Reece, 2019).

This can be different for a pregnant woman, since the placenta is an organ temporarily required for the creation of a fetus, in early pregnancies the glycogen is made by the placenta to feed the fetus (American Pregnancy Association, 2015). The fetus receives oxygen and nutrients from its mother and is given immunity towards certain sicknesses from the antibodies it gets from the mother through the placenta. The placenta is a protective barrier that keeps the mother’s immune system from targeting the fetus as an invader. One of the most dangerous things for a mother and infants health is hypertension, since it can cause the placenta to receive little blood, and if it doesn’t get enough, the baby will not get enough food and oxygen to survive (American Pregnancy Association, 2015). This can cause a low birth rate but if it is caught early on, the woman can still deliver a healthy baby, but on the dark side, if you don’t catch it you can develop preeclampsia, which has some serious effects on the mother and baby’s health (American Pregnancy Association, 2015).

After everything I learned from this, I cannot stress how important homeostasis is for the body, actually for survival. I mean without it we would literally die, if our temperature is too high or low, we either get heatstroke or hypothermia, having no control over water balance, can cause you to become hyper-hydrated or dehydrated, all of these can literally kill you (Nguyen, 2018). Without any control over the amount of calcium in blood, you can get hypercalcemia or hypocalcemia, and if the body is unable to manage energy, then you can get diabetes or become obese (Simon, Dickey, Hogan & Reece, 2019). Basically, everything that goes wrong with body maintenance can cost you your life, so yes, it is important that we have homeostasis.