Exploring the Structures & Function of the Kidneys PDF

Exploring the Structures & Function of the Kidneys Ryan Barker 2021.09.13 SBI4U Kidney’s play an extremely important role in the function of the body. They are responsible for over 20% of the blood supply in the body at any time. The bod...

Exploring the Structures & Function of the Kidneys Ryan Barker 2021.09.13 SBI4U Kidney’s play an extremely important role in the function of the body. They are responsible for over 20% of the blood supply in the body at any time. The body regulates the acidity and osmolality of the blood, which in turn produces waste products that flow and are filtered through the kidneys. The kidneys ensure that our body stays at a regulated level by turning waste into urine. Blood enters the kidney through the Renal Artery, a tube that is highlighted on the diagram above. It then enters into the Glomerulus, an important part of the Nephron. The Glomerulus is a bundle of Capillaries that are the primary source of filtration in the kidney. The thin walls of the Glomerulus are important in allowing small molecules, waste, and primarily water, to enter and pass into the tubule. The Glomerulus is responsible for turning blood into filtrate that eventually becomes excreted through urine. The filtrate that filters through the Glomerulus enters into what is known as Bowman’s Capsule. The filter is a combination of endothelial cells and a basement membrane, which allow waste products to pass, but stop the filtration of larger proteins, amino acids, and red/white blood cells. The capsule hugs the Glomerulus and the filtrate sits in Bowman’s space, inside of the capsule. All of the excess in the blood that is not filtered through the Glomerulus is given back to the body by the process of reabsorption. The body needs things such as Na+, Red/White blood cells, Nutrients, and water. These are reabsorbed from the proximal tube with the filtrate, and back into the bloodstream which flows through the capillaries, and the capillary network. The nutrients and ions are specifically reabsorbed by the mitochondria in the proximal tubule which use the energy of adenosine triphosphate to actively transport essential ions and nutrients back into the bloodstream. The proximal tube is the primary region where the important ions and nutrients are reabsorbed into the bloodstream. Another important region of the nephron is the Loop of Henle. The Loop has two parts, the descending loop and the ascending loop. The descending loop is where water enters the capillary via osmosis, and waste solute diffuses into the filtrate flow. The ascending loop is where necessary solute is diffused back into the capillary network, along with essential ions, such as sodium, potassium, and chlorine. The sodium(Na+) is extremely important as it aids the salty climate of the medulla region, which increases the absorption of water from the filtrate flow and continues the necessary blood flow and reabsorption process. The reabsorption process is extremely important in the body's function as it plays a key role in the body’s homeostasis. If the body was constantly losing water and key nutrients/ions through urine it would not be able to function and would constantly be dehydrated among other difficulties. When necessary items are reabsorbed it provides the body the perfect climate to maintain a constant body temperature, blood pH, blood sugar level, and water level. This leads to the body being able to maintain homeostasis. Reabsorption continues into the Distal Tube, and ions are both actively and passively transported into the capillaries. Other substances that are transported in the distal tubule are medications, such as insulin. As the filtrate continues the reabsorption process throughout the collecting ducts and the renal pelvis it eventually ends and is now considered urine. The urine flows through the renal pelvis and then into the ureters which transport the urine to the bladder, where it sits until it is released via the urethra and into the environment outside. Aldosterone and ADH are both important hormones that maintain water balance in the body. Aldosterone is released in order to combat sensors that detect low blood pressure and low blood volume. It is released in order to maintain sodium and water. This hormone may be released when there is a large injury that causes loss of blood (i.e hemorrhage). ADH Is used to help the kidneys understand how much water that the body needs to function. It is released by the pituitary gland in the brain that senses when there is an increase in blood osmolality or a decrease in blood volume. The kidneys adjust to ADH by conserving water and producing more concentrated urine. Both hormones provide feedback to the body on how to achieve a balanced water and sodium level. References https://www.niddk.nih.gov/health-information/kidney-disease/kidneys-how-they-work https://www.youtube.com/watch?v=ctGkLYuUCvU https://www.youtube.com/watch?v=wWsdcfGta4k