Homeostasis By Riley Echtenkamp What is Homeostasis Homeostasis

Homeostasis By: Riley Echtenkamp

What is Homeostasis? Homeostasis is the process that keeps the bodily functions and conditions working at a steady, constant rate. Homeostasis controls 4 main bodily functions: osmoregulation, thermoregulation, chemical regulation, and behavioral homeostasis However, homeostasis also has its own “inner processes” called negative and positive feedback along with sensors in the body.

Osmoregulation is body cleaning itself out by getting rid of all of the extra water, salt, and urea in the body. These things are sent out of the body through the kidneys, urinary bladder, ureters, urethra, pituitary glands, and the lungs. Osmoregulation is a vital part in keeping the kidney and the bladders functioning properly.

Thermoregulation is the process of the body maintaining a constant body temperature. If the body is over heating, it will begin to sweat and dilate the blood vessels in order to bring the body temperature back down to a constant degree. Pilorelaxation: the hair on the body flattens to the skin If the body is too cold, it will begin to shiver, constrict the blood vessels, and provide insulation (adipose tissue & other combined tissues) in order to bring the body temperature back up to a constant degree. Piloerection: the hair on the body stands up off the skin

Thermoregulation cont`d 2 types of heat regulation Endothermic: organism regulates its own body temperature. Exothermic: body temperature depends on the environment in which the organism lives. Body Systems involved: muscular system, nerves, blood vessels, skin, and adipose tissue

Chemical Regulation is the process of regulating the glucose levels in the body. This is done by secreting/ releasing insulin and glucagons into the blood stream to either bring up or lower the glucose level. Also adjusts the body` s breathing rate based on the amount of carbon dioxide levels in the blood stream. In addition to that, it also keeps the creating of red blood cells constant by releasing erythropoietin from the kidneys

Chemical Regulation cont`d It can also involve the hormonal system. The hormones that the body needs are created in the islets of Langerhans area of the pancreas. If there is a spike in the glucose levels, beta cells will detect the rise. After these beta cells are alerted, the cells will then know they need to make more insulin. The extra insulin in the pancreas would then be used to link together receptor proteins in the liver. This allows for more protein channels to be opened up, and that allows the glucose to enter the beta cell. Once the glucose has entered the cell, it will then be converted into glycogen.

Behavioral Homeostasis The process of the body remaining constant by altering the actions/ responses of the body due to its environment. Very similar to thermoregulation. Behavioral Homeostasis works much like a thermostat in a house. If thermostat is set to a certain temperature, the air conditioner/ heater will come on and off based on whether the room needs to cool down or heat up in order to reach that steady temperature. Examples of behavioral homeostasis include shivering, pilorelaxation, piloerection, constricting/ dilating of the blood vessels, etc.

Inner Processes of Homeostasis has its own “inner processes” that have to take place in order for the other process of homeostasis to occur. These inner processes include: negative and positive feedback

Negative Feedback Kicks in when a system needs to be slowed down or stopped completely. An example of negative feedback would be when the body begins to over heat. Negative feedback will stop the rise of temperature. This will cause the body to sweat.

Positive Feedback It supports the system that is carrying out the job. Can be thought of as the “encouragement” to the body system that is working. This helps the system work more efficiently and effectively. Positive feedback is constantly going on inside the body until it is stopped by negative feedback. A great example of positive feedback would occur in the stomach. The pepsinogen that is created in the stomach is then converted into an enzyme known as pepsin. This is repeated over and over until there is enough pepsin molecules to digest the proteins in the stomach.

Sensors detect rise, spikes, or drops in the supply of an item/ particle that is necessary to the body. The sensors alert the brain, and then the brain activates either negative or positive feedback.

Homeostasis in Plants Photosynthesis=Homeostasis Photosynthesis is the process of releasing water from the plant, and taking in carbon dioxide. It is necessary for photosynthesis to be carried out. If photosynthesis is not performed and a plant does not maintain a constant state, it will wilt and die. The stomata of the plant would be the place where all gases enter the cell. Water can also leave the cell through here. Guard Cells: open to take in carbon dioxide and release water. Acts as the “gate keeper” or “security guard” of the stomata.