| 翻訳と辞書 |
nephron
The nephron (from Greek νεφρός - nephros, meaning "kidney") is the basic structural and functional unit of the kidney.〔Pocock, G. Human Physiology.Oxford University Press.Third edition.2006. Page 349.〕 Its chief function is to regulate the concentration of water and soluble substances like sodium salts by filtering the blood, reabsorbing what is needed and excreting the rest as urine. A nephron eliminates wastes from the body, regulates blood volume and blood pressure, controls levels of electrolytes and metabolites, and regulates blood pH. Its functions are vital to life and are regulated by the endocrine system by hormones such as antidiuretic hormone, aldosterone, and parathyroid hormone. In humans, a normal kidney contains 800,000 to 1.5 million nephrons.
==Structure==
The two general classes of nephrons are cortical nephrons and juxtamedullary nephrons, both of which are classified according to the length of their associated Loop of Henle and location of their renal corpuscle. All nephrons have their renal corpuscles in the cortex. ''Cortical'' nephrons have their Loop of Henle in the renal medulla near its junction with the renal cortex, while the Loop of Henle of juxtamedullary nephrons is located deep in the renal medulla; they are called ''juxtamedullary'' because their renal corpuscle is located near the medulla (but still in the cortex). The nomenclature for cortical nephrons varies, with some sources distinguishing between ''superficial cortical nephrons'' and ''midcortical nephrons'', depending on where their corpuscle is located within the cortex.
The majority of nephrons are cortical. Cortical nephrons have a shorter loop of Henle compared to juxtamedullary nephrons. The longer loop of Henle in juxtamedullary nephrons create a hyperosmolar gradient that allows for the creation of concentrated urine.
Each nephron is composed of an initial filtering component (the "renal corpuscle") and a tubule specialized for reabsorption and secretion (the "renal tubule"). The renal corpuscle filters out solutes from the blood, delivering water and small solutes to the renal tubule for modification.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「nephron」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|