Quick Facts
The nephron is the anatomic and functional unit of the kidney, consisting of the renal corpuscle, the proximal convoluted tubule, the descending and ascending limbs of the loop of Henle, the distal convoluted tubule, and the collecting tubule (Dorland, 2011).
Structure and/or Key Feature(s)
Juxtamedullary nephrons are characterized by a long renal tubule which extends deep into the medulla. Approximately 15% of human nephrons have long loops, where the thin portion of their nephron loop passes deep into the renal papillae and can measure up to 14 mm in length (Standring, 2016).
Anatomical Relations
Each nephron is comprised of a renal corpuscle and the associated renal tubule. In juxtamedullary nephrons, the renal corpuscle is generally located in the cortex of the nephron, near the corticomedullary border, while the renal tubules pass and extend down into the medulla, often reaching as far as the renal papilla. The nephron is surrounded by a complex network of capillaries which facilitate the functional reabsorption of water and salts into the bloodstream (Zhuo & Li, 2013).
Function
The nephron is largely responsible for the filtration of blood, the reabsorption of water and salts, and the production of urine. Specific regions of the renal tubule of the nephron are responsible for reabsorbing different minerals (Pocock et al, 2013).
List of Clinical Correlates
—Diabetic nephropathy
—Glomerulonephritis
—Acute tubular necrosis
—Polycystic kidney disease
References
Dorland, W. (2011) Dorland's Illustrated Medical Dictionary. 32nd edn. Philadelphia, USA: Elsevier Saunders.
Pocock, G., Richards, C. D. & Richards, D. A. (2013) Human Physiology, 4 edition. OUP Oxford.
Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical PracticeElsevier Limited.
Zhuo, J. L. & Li, X. C. (2013) Proximal nephron. Comprehensive Physiology, 3(3), 1079-1123.
