Nakul Bansal is teaching live on Unacademy Plus
Excretory Products and their Elimination By Nakul Bansal 2nd year MBBS student VMMC and SJH, New Delhi 84 AIR in NEET 2016 -
Introduction -Various excretory organs in different organisms Waste products of protein metabolisnm -Human excretory system -Structure of nephron -Juxta glomerular apparatus -Urine formation -Concentration of urine -Micturition -Regulation of kidney functions -Disorders, dialysis, transplants -Extra topics
XCRETION: Elimination of metabolic waste products from the animal body to regulate the composition of the body fluids and tissues. Various excretory products are - ammonia, urea, Carbon dioxide, sweat, sebum DEFECATION: It is elimination of undigested food residue from alimentary canal in form of faeces. *Defecation should never be confused with excretion because the former is elimination of waste which has remained undigested whereas the latter is the removal of waste which has been generated by the cells in various metabolic processes.
OSMOREGULATION: It is maintenance of osmotic concentration inside body cells and extracellular fluids by controlling the amount of water and salts. How nitrogenous waste is generated? In this set of lessons we will be focusing mainly on the elimination of the nitrogenous waste from the body. As we know that fats and carbohydrates can be stored in the human body but there is no method or way for the storage of amino acids in the body so the excess amino acids are generally deaminated to form ammonia and corresponding a- keto acids.
Need for elimination of Ammonia Urea is formed from the conversion of ammonia using urea cycle in the liver. The ammonia is formed in all the cells of the body because of various processes which lead to breakdown of amino acids releasing their amino group. The accumulation of ammonia in the cells lead to utilization of a-ketoglutarate, which is quite essential for the running of the Krebs' cycle or TCA cycle, which in turn is required for the release of energy. a-ketoglutarate is converted to glutamate and hence cannot be used un TCA cycle. So if ammonia gets accumulated the cells get energy deprived and they die
Excretion ,DIGESTION , Arv INO ACEDS IN GUT INTESTINECTRGU LATION USEFUE AMINo ACIDS EXCESS AMINO ASSIMIIATION IN CELLS ENTER LIVE R FoR DEAM INATION UREA REACHES NH FORMED GOES KrDNEY --. TO UREA CYCLE EXCRETION