Excretory System Overview and Kidney Function

The three main parts of the kidney are the cortex, medulla, and pelvis. The cortex contains nephrons which filter blood. The medulla contains the loops of Henle and collecting ducts which concentrate urine. The pelvis collects and drains urine into the ureter.

Urine formation involves three steps: filtration, reabsorption, and secretion. Filtration occurs in the glomerulus, where blood is filtered and primary urine is formed. Reabsorption occurs in the proximal convoluted tubule, where essential substances are reabsorbed back into the blood. Secretion occurs in the distal convoluted tubule and collecting ducts, where final adjustments to the urine composition are made.

Albuminuria is the presence of protein in urine, while hematuria is the presence of blood in urine. Both conditions indicate kidney damage because healthy kidneys should not allow these substances to pass into the filtrate.

<p>Glucose is normally reabsorbed in the proximal convoluted tubule during urine formation. In diabetes mellitus, blood glucose levels are high, and the kidneys may not be able to reabsorb all of it, leading to glucose being excreted in the urine.</p> Signup and view all the answers

<p>The loop of Henle and collecting ducts create a concentration gradient in the medulla, causing water to be reabsorbed from the urine, concentrating it. This process is essential for maintaining water balance in the body.</p> Signup and view all the answers

<p>Uremia is a condition characterized by high levels of non-protein nitrogen waste products in the blood. It is caused by kidney failure, where the kidneys are unable to effectively filter these wastes. Treatment options include hemodialysis, which filters the blood outside of the body.</p> Signup and view all the answers

<p>Renal failure is a condition where the kidneys stop functioning properly. This can range from mild to severe, with severe cases requiring a kidney transplant to survive.</p> Signup and view all the answers

<p>Renal calculi are solid crystals that form in the kidneys. They can block the flow of urine, causing pain and potentially leading to infection or kidney damage.</p> Signup and view all the answers

<p>Glomerulonephritis is an inflammation of the glomerulus. It is caused by damage to the glomerulus, which can be caused by infections, autoimmune diseases, or other factors.</p> Signup and view all the answers

<p>Excretion is essential for removing waste products from the body, maintaining the balance of water and electrolytes, and preventing the accumulation of toxins that could harm bodily functions.</p> Signup and view all the answers