URINARY SYSTEM

• KIDNEY - a vital organ in the human body responsible for filtering waste products from the blood and regulating fluid balance.
• Each kidney is about the size of a fist (10-12 cm long) and weighs approximately 150 grams.
• RENAL CORTEX - this is the outer layer of the kidney. It contains nephrons, which are the functional units responsible for filtering the blood and producing urine.
• RENAL MEDULLA - this is the inner part of the kidney, consisting of renal pyramids and renal columns. It helps to transport urine from the nephrons to the renal pelvis.
• RENAL PELVIS - this is a funnel-shaped structure in the center of the kidney where urine collects before it moves into the ureter. It serves as a reservoir for urine.
• NEPHRONS -These are microscopic structures within the kidney that perform the filtration of blood and the formation of urine. Each nephron consists of a renal corpuscle (glomerulus and Bowman's capsule) and renal tubules (proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting duct).
• GLOMERULUS - A network of capillaries where blood filtration occurs.
• BOWMAN'S CAPSULE - A cup-shaped structure surrounding the glomerulus that collects the filtrate.
• PROXIMAL CONVOLUTED TUBULE (PCT) - The first segment of the renal tubule where reabsorption of water, ions, and nutrients from the filtrate back into the blood occurs.
• LOOP OF HENLE - A U-shaped loop that plays a crucial role in concentrating urine by reabsorbing water and salts.
• DISTAL CONVOLUTED TUBULE (DCT) - The segment of the renal tubule that further adjusts electrolyte balance and pH of the urine.
• COLLECTING DUCT - This structure collects urine from multiple nephrons and transports it to the renal pelvis.
• RENAL ARTERY AND RENAL VEIN - The renal artery supplies oxygenated blood to the kidneys, while the renal vein carries deoxygenated blood away from the kidneys after filtration.
• URETERS - These are tubes that carry urine from the kidneys to the urinary bladder. Peristaltic contractions help move urine through the ureters.
• POLYURIA - Excessive urine output due to increased fluid intake or decreased ability to concentrate urine.
• URINARY BLADDER - This is a muscular sac that stores urine until it is expelled from the body during urination.
• URETHRA - This is the tube that carries urine from the bladder to the outside of the body during urination. In males, it also serves as the passage for semen during ejaculation.
• The renal cortex contains millions of nephrons, which are the functional units of the kidney responsible for filtering blood and producing urine.
• The renal cortex houses the glomeruli, which are tiny clusters of blood vessels where filtration of blood occurs.
• The renal medulla consists of renal pyramids, which are cone-shaped structures, and renal columns, which are extensions of cortical tissue between the pyramids.
• • Within the renal pyramids are structures called nephrons, including the loops of Henle and collecting ducts, which play crucial roles in concentrating urine.
• The renal pelvis is a funnel-shaped structure located in the center of the kidney.
• The renal pelvis collects urine from the nephrons and funnels it into the ureter, which carries urine to the urinary bladder.