Pronunciation: [kˈɪdnɪ] (IPA) 
The word "kidney" is spelled with the letter "k" followed by "i" pronounced as /ɪ/ and "d" pronounced as /d/. The next two letters are "n" pronounced as /n/ and "e" pronounced as /i:/ or /ɛ/ depending on the speaker's accent. The last letter is "y" pronounced as /i/. The word comes from the Old English "cýðan," meaning "to make known." The kidneys are a vital organ in the human body responsible for filtering waste and excess fluids.
The kidney is one of the fundamental organs found in vertebrates, primarily mammals, which serves a crucial role in maintaining homeostasis. It is a paired organ, with two kidneys located on either side of the vertebral column in the lower back region. Functioning as vital excretory organs, the kidneys play a central role in filtering and removing waste products, excess fluid, and toxins from the bloodstream through the production of urine.
The kidneys are responsible for regulating electrolyte concentrations, such as sodium and potassium, and maintaining adequate fluid balance within the body. Additionally, they contribute to the regulation of blood pressure and the production of erythropoietin, a hormone involved in red blood cell production. These organs are composed of various components, including nephrons, the structural and functional units responsible for blood filtration and urine formation.
Pathological conditions affecting the kidneys can result in severe consequences for overall health. Kidney diseases, ranging from infections to chronic conditions like chronic kidney disease, can impair renal function, leading to complications such as fluid retention, electrolyte imbalances, and impaired waste removal. Various treatment options, including medication, dietary modifications, and sometimes dialysis or kidney transplantation may be necessary to manage kidney-related conditions.
In summary, the kidneys are essential organs that contribute to the maintenance of homeostasis by regulating various physiological parameters, removing waste products from the bloodstream, and producing urine.
One of the two organs which excrete the urine. The kidneys are bean-shaped organs, about 4 1/2 in. in length, 2 in. in width, and 1 1/4 in. in thickness, lying on either side of the spinal column, behind the peritoneum, about opposite the twelfth thoracic and first three lumbar vertebrae. At the inner edge of each kidney is a concave depression, the hylus, where the vessels and nerves enter and leave the organs and where the ureter emerges; the hylus leads into the renal sinus, a hollow containing the pelvis and calyces and the branching blood-vessels. The kidney is enclosed in a fibrous envelope, the capsule, which dips into the sinus at the hilus. The substance of the organ is divided into cortex and medulla; the former is darker colored and more granular in appearance than the latter; it contains the Malpighian corpuscles and most of the convoluted tubules; the medulla is lighter in color and striated and contains the majority of the straight tubules; it is formed of the pyramids whose bases rest in the cortex and whose apices are the renal papillae at which point the central collecting tubule opens into a calyx, this in turn emptying into the pelvis of the kidney from which the water passes into the ureter and so reaches the urinary bladder. The pyramids are made up of tubules; each tubule begins at the glomerulus, or Malpighian corpuscle, in the cortex; it is first convoluted, then enters the pyramid, passing down toward the papilla, near which it turns back on itself, the turn being called Henle's loop, it then ascends to the cortex, where it is again convoluted (being called the irregular tubule), and returns to the pyramid in the center of which it empties into the straight collecting tube, which terminates, usually after uniting with others, at the apex of the papilla. Projections of masses of tubules pass up into the cortex, being known as medullary rays, while the cortical substance often passes down between the pyramids, forming the so-called columns of Berlin; the cortical substance between the medullary rays is also called the labyrinth.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
* The statistics data for these misspellings percentages are collected from over 15,411,110 spell check sessions on www.spellchecker.net from Jan 2010 - Jun 2012.
The word "kidney" has an interesting etymology. It originated from the Old English word "cwiðanēage", which was derived from the West Germanic word "kīwident" meaning "kidneys". The Old English word "cwiðanēage" can be further broken down into "cwiðan", which means "womb", and "ēage", which means "eye". This is because the shape and color of the kidney were thought to resemble a fetal eye. Over time, the word evolved through Middle English and eventually became the modern English term "kidney".
