Kidney

• The kidneys are located on either side of the vertebral column, with the right kidney slightly lower than the left.
• Each kidney is about 10-12 cm long, 5-6 cm wide, and 3 cm thick.
• The renal hilum is where blood vessels enter and exit the kidney.
• The renal pelvis is a funnel-shaped structure that collects urine from the nephrons and leads to the ureter.
• Each kidney is about 10-12 cm long, 6 cm wide, and 3 cm thick.
• Veins drain deoxygenated blood away from the kidneys back into the inferior vena cava (IVC).
• The calyces are cup-like structures within the renal pelvis that receive urine from the collecting ducts.
• Renal arteries branch from the abdominal aorta to supply oxygenated blood to the kidneys.
• Veins drain deoxygenated blood away from the kidneys back into the inferior vena cava.
• Nerves innervate the kidneys through sympathetic nerves that originate in the thoracic spinal cord (T9-L2).
• The renal sinus contains fatty tissue and lymphatic vessels.
• The kidneys are retroperitoneal organs, meaning they lie behind the peritoneum (the lining of the abdominal cavity).
• Renal artery branches into smaller arteries called interlobar arteries, which branch further into arcuate arteries.
• Nephron: The functional unit of the kidney responsible for filtering blood and producing urine.
• The kidneys receive oxygenated blood through the renal artery and drain into the inferior vena cava via the renal vein.
• Arcuate arteries divide into afferent arterioles, which supply oxygenated blood to glomeruli.
• Interlobular arteries give rise to afferent arterioles, which enter glomeruli.
• Loop of Henle: Responsible for creating an osmotic gradient between the medulla and cortex.
• Segmental arteries divide into interlobular arteries, which supply individual nephrons.
• Proximal convoluted tubule: Filters out useful substances such as glucose and amino acids.
• Each kidney is supplied by one main renal artery, which divides into segmental arteries within the cortex.
• Glomerulus: A tuft of capillaries within Bowman's capsule where filtration occurs.
• Efferent arterioles leave nephrons and join venules, forming larger veins.
• The renal pyramids are cone-shaped masses of nephrons extending from the cortex towards the center of the kidney.
• The hilum is an opening on the medial side of the kidney where blood vessels enter/exit and nerve fibers exit.
• The renal medulla is an inner region of the kidney with pyramid-shaped segments called renal pyramids.
• Each kidney is surrounded by a fibrous capsule called the renal fascia or Gerota's fascia.
• The renal cortex is the outermost region of the kidney, containing nephrons and other functional units.
• The renal capsule is a thin layer of connective tissue surrounding the kidney.
• Parasympathetic stimulation decreases heart rate, dilates blood vessels, and promotes secretion of renin by juxtaglomerular cells.
• Sympathetic stimulation increases heart rate, constricts blood vessels, and inhibits secretion of renin by juxtaglomerular cells.
• Bowman's capsule - surrounds glomerulus and forms part of proximal convoluted tubule.
• Glomerulus - network of capillaries where filtration occurs.
• Parasympathetic fibers arise from the sacral region of the spinal cord (S2-4) and travel with the hypogastric nerve.
• Nephron - functional unit of the kidney responsible for filtering blood and producing urine.
• Renal artery: A major artery that supplies blood to the kidneys.
• Bowman's capsule: Surrounds the glomerulus and forms part of the filtration process.
• Glomerulus: A cluster of capillaries located at the beginning of each nephron.