The Bradshawe Lecture on Uraemia

Urine formation is an essential function of the human body. It plays a critical role in maintaining homeostasis by regulating the volume and composition of body fluids. The kidneys, the primary organs involved in this process, filter blood to remove waste products and excess substances, ultimately producing urine.
Glomerular Filtration
The first stage in urine formation is glomerular filtration. Each kidney contains approximately 1 million nephrons, the functional units of filtration, with a...

Metabolic reactions in the body produce nonvolatile acids, such as sulfuric acid, which generate an acid load of approximately 1 mEq of H+ per kilogram of body weight daily. Excreting H+ in the urine is essential to balance this acid load.
In the kidneys, cells within the proximal convoluted tubules (PCT) and the collecting ducts secrete hydrogen ions (H+) into the tubular fluid. Specifically, in the PCT, Na+/H+ antiporters secrete H+ while reabsorbing Na+.
However, the intercalated cells in...

The urinary system consists of two kidneys, two ureters, the urinary bladder, and the urethra.
The kidneys are bean-shaped organs located in the retroperitoneal space, on either side of the vertebral column, between the T12 and L3 vertebrae. They are partially protected by the rib cage and surrounded by perirenal fat, which provides cushioning. They are responsible for urine formation and play critical roles in regulating blood pressure, electrolyte levels, and hormone production. The ureters...

Urinalysis is a widely used diagnostic test that analyzes urine's physical, chemical, and microscopic characteristics. Healthcare providers use it to detect and monitor various health conditions, including renal disease, urinary tract infections (UTIs), diabetes, and metabolic or systemic disorders.Components of UrinalysisUrinalysis consists of three primary components: physical, chemical, and microscopic examination. Each provides unique insights into the urine sample and, by extension, the...

Jaundice, or icterus, is the yellow discoloration of the skin, sclerae, and mucous membranes. It happens when plasma bilirubin levels rise above 2.5-3 mg/dL, leading to bilirubin deposition in tissue.Bilirubin is a byproduct of hemoglobin degradation. In macrophages, hemoglobin breaks down into globin and heme. Globin is converted into amino acids, while heme is turned into biliverdin by heme oxygenase, which is then reduced to unconjugated bilirubin by biliverdin reductase.Unconjugated...

Hemodialysis (HD) is a medical treatment that artificially removes waste products, excess fluids, and toxins from the blood when the kidneys are no longer able to perform these functions effectively. In this process, blood is filtered through a semipermeable membrane, allowing for the selective removal of waste while preserving necessary components like blood cells and proteins. Hemodialysis is typically performed in patients with end-stage renal disease (ESRD) or severe kidney...