kidneys(redirected from Renal function)
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kidneyspaired organs in the back of the abdomen. By filtration of water and small molecules from the blood flowing through the capillary complex of their glomeruli, they extract about 1/5 of the whole blood volume per minute, for passage into the tubules where, by selective reabsorption back into the blood, the quantity and content of the urine are regulated. By these means, under the influence of hormones they excrete waste substances and regulate electrolyte and acid-base balance, as well as blood volume, and the concentration of various substances in the blood. They also secrete renin and renal erythropoietic factor and are involved in vitamin D metabolism. See also Table 1.
|Site of production||Name of hormone||Main targets||Involved in regulating:||Secretion controlled by:|
|Hypothalamus||Releasing and inhibiting hormones||Anterior pituitary (via local blood vessels)||Secretion of anterior pituitary hormones||Other brain regions; feedback re regulated hormones and their actions|
|Neurohormones released from posterior pituitary:|
|Oxytocin||Uterus, breasts||Labour and lactation||Afferent information from target organs|
|Antidiuretic hormone (ADH, vasopressin)||Kidneys||Water loss: ECF volume and osmolality||Hypothalamic osmoreceptors|
|Anterior pituitary||(Human) growth hormone (H)GH||Most cells||Growth and metabolism||Hypothalamic releasing and inhibiting hormones via local blood vessels|
|Thyroid-stimulating (TSH)||Thyroid gland||Thyroid secretions|
|Gonadotrophins||Ovary or testis||Germ cell maturation and hormone secretions|
|Adrenocorticotrophic (ACTH)||Adrenal cortex||Cortisol secretion|
|Pineal body||Melatonin||Widespread, including brain, thymus, etc.||Hypothalamus; varying light input from retina|
|Parathyroids||Parathormone||Bone, kidneys, gut||ECF [Ca2+]|
|Medulla||Heart, smooth muscle, glands||Cardiovascular and metabolic adjustments to activity and stress||Sympathetic nervous system|
|Atrial wall||Atrial natriuretic hormone||Kidneys||Blood volume; increases sodium (therefore also water) loss in urine||Stretch of atrial wall by venous pressure|
|Gonads: Testis||Androgens (mainly testosterone)||Genitalia and other tissues||Reproductive function and sex characteristics||Anterior pituitary gonadotrophins|
|Ovary||Uterus, breasts and other tissues||Menstrual cycle, pregnancy, lactation|
|Pancreas||Blood levels, storage and cellular uptake of nutrients, notably glucose, but also proteins and fats||Blood levels of nutrients; autonomic nervous system; other gastrointesinal hormones|
|Stomach||Gastrin||Gastric acid-secreting cells||Gastrointestinal functions: motility, digestive juices and other secretions||Local chemical and mechanical factors in the alimentary tract|
|Small intestine||Several GI functions including bile flow, pancreatic enzyme and exocrine secretions||Ingestion of food, distension of GI tract|
Patient discussion about kidneys
Q. Why do i get kidney stones? I am 38 and have had three stones pass so far. Is it the coffee, the meat, the stress, or the damned DNA?! My uncle is in his 50s and has passed over 30 stones!
Q. How can i overcome kidney ache? in the morning it appears.after wake up.
Q. what cause pain around kidney uncomfortable pressure swelling right side back