Welcome to this lesson on urine formation overview. Today, you will be looking at an overview on how urine is formed by the body. Specifically, you will learn about:
So urine is a substance formed by the kidneys in order to maintain homeostasis of extracellular fluids. Extracellular fluids are fluids found outside of the cells, such as blood and tissue fluid. By forming urine the kidneys help keep solute levels of those extracellular fluids from getting too high or low. By doing this, the kidneys also control blood volume and pressure.
Nephrons are structures in the kidneys that filter water and solutes from blood and produce urine. Nephrons span the cortex and medulla of the kidneys and produce urine through the three following steps: filtration, reabsorption, and secretion.
Filtration is the first step in urine formation, and it takes place within Bowman's capsule. Here, water and solutes are filtered out of the blood through glomerular capillaries within the Bowman's capsule.
Reabsorption, which is the second step in urine formation, takes place mostly in the proximal tubule, which comes off of Bowman's capsule. Secretion, which is the third step in urine formation, starts at the proximal tubule and continues along the loop of Henle and continues through the distal tubule. Once urine has formed, it will move into the collecting duct and the collecting duct will deliver that urine into the renal pelvis of the kidney. From here it will filter down into the ureters and then down into the urinary bladder where, it's stored until it's excreted..
So this lesson has been an overview on urine formation and nephron structure.
Keep up the learning and have a great day!
Source: THIS WORK IS ADAPTED FROM SOPHIA AUTHOR AMANDA SODERLIND
The first step in urine formation in which urine is filtered from afferent arterioles in the bowman's capsule of a nephron.
The second step in urine formation in which valuable water and solutes are reabsorbed back into the blood.
The third step in urine formation in which filtrate moves toward collecting ducts; secretion helps maintain the body's acid-base balance.