Processes involved in the human kidney Essay Example for Free

Processes involved in the human kidney Essay-Blood enters each kidney via renal artery and leaves each kidney via renal vein-Urine exists the kidney through a duct called the ureter and the uruters of both kidneys drain into a common urinary bladder-Kidney consists of outer renal lens cortex and inner renal medulla-Nephron is functional unit of vertebrate kidney-Consists of single long tubule and ball of capillaries called the glomerulus-Bowmans space capsule surrounds the glomerulus-Kidney regulates the composition of the roue and produce urine-Filtration occurs as lineage pressure forces water, urea, flavours, and other small solutes from the blood in the glomerulus into the Bowmans capsule-Nonselective-Filtrate goes into proximal tube, loop of Henle (a hairpin turn with a descending limb and ascending limb) and the distal tubule-Kidney consists of cortical nephrons and juxtamedullary nephrons (only in mammals and birds)-Most of filtrate is absorbed back into blood the kidne ys take out about 1%-Proximal and distal tubules are the most common sites of secretion-Very selective process with both passive and active bear of solutes-Proximal, distal tubules, and loop of Henle contribute to Reabsorption-Collecting duct also helps in Reabsorption-Mammalians kidneys ability to defend water is considered an important adaptation-Antidieretic hormone is important in os muchgulation-Made in hypothalamus and released when osmolarity in blood rises preceding(prenominal) certain point-ADH acts on the distal tubules and collecting ducts by increasing their permeability to water-Causes more water Reabsorption-Is turned off through negative feedback-Juxtaglomerulur apparatus located in the region of the afferent arteriola, which supplies blood to the glomerulus-When blood pressure or blood volume in the afferent arteriole drops, the enzyme rennin causes chemical reactions that create a peptide called angiotensin II-Angiotensin II increases blood pressure and blood vo lume by constricting arterioles and decreasing blood flow to many capillaries like the kidney-Causes more salt and water reabsorption to increase blood volume-Causes release of aldosterone, which also acts on nephrons distal tubules and helps, reabsorb more sodium and water-Negative feedback turns rennin production off-Called the rennin-angiotensin-aldosterone system-Atrial natriuretic factor opposes RAAS-Released by the heart in response to an increase in blood volume and pressure-Inhibits the release of rennin-Inhibits NaCl reabsorption and reduces aldosterone release from adren