logging in or signing up EXCRETORY SYSTEM rittwik3 Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: Embed: Flash iPad Dynamic Copy Does not support media & animations Automatically changes to Flash or non-Flash embed WordPress Embed Customize Embed URL: Copy Thumbnail: Copy The presentation is successfully added In Your Favorites. Views: 1203 Category: Education License: All Rights Reserved Like it (0) Dislike it (0) Added: May 10, 2011 This Presentation is Public Favorites: 1 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Slide 1: EXCRETORY SYSTEM 5/10/2011 1 SUBMITTED BY : RITTWIK SOOD ROLL NO : 10234 SUBMITTED TO : MR. RAJINDER SIRSlide 2: 5/10/2011 2 THE BIOLOGICAL PROCESS INVOLVED IN THE REMOVAL OF HARMFUL METABOLIC WASTES DEFINITION OF EXCRETIONSlide 3: 5/10/2011 3 DIFFERENT ORGANISMS USE DIFFUSION FOR THE EXCRETIONSlide 4: 5/10/2011 4 EXCRETION IN HUMAN BEINGSSlide 5: 5/10/2011 5Slide 6: In order for cells to stay alive, they must continually intake water and other molecules. The cells would continue to get bigger and bigger if they only took in molecules They must also export molecules These molecules may be important signaling molecules such as hormones, or they may be molecules of glucose on their way to other cells, or they may be waste products of cellular metabolism that cells need to dispose. 5/10/2011 6 NEED OF EXCRETIONREMOVAL OF NITREGENOUS WASTES: REMOVAL OF NITREGENOUS WASTES Ammonia (NH 3 ) URIC ACID UREA 5/10/2011 7Slide 8: 5/10/2011 8 PARTS OF EXCRETORY SYSTEMSlide 9: 5/10/2011 9 KIDNEYKIDNEYS SHAPE AND SIZE: KIDNEYS SHAPE AND SIZE 4 inches long and 2 inches wide The kidneys are fist-sized, bean shaped structures that remove nitrogenous wastes (urine) and excess salts from the blood. Each kidney is composed of three sections: the outer (renal) cortex, the (renal) medulla (middle part) the hollow inner (renal) pelvis . 5/10/2011 10 KIDNEYS functioning : KIDNEYS functioning 5/10/2011 11 They are responsible for cleaning the blood by removing metabolic wastes, excess solutes, and excess water and excreting them as urine Besides removing urea, it also removes excess salts or glucose, the remnants of drugs (reason for urine tests), and excess water. The principal function of the kidney is to filter blood in order to remove cellular waste products from the body. URINARY BLADDER : URINARY BLADDER 5/10/2011 12URINARY BLADDER : URINARY BLADDER The urinary bladder is the organ that collects urine excreted by the kidneys prior to disposal by urination. It is a hollow muscular, and distensible (or elastic) organ, and sits on the pelvic floor. Urine enters the bladder via the ureters and exits via the urethra. Urinary bladder is muscular so it is under nervous control 5/10/2011 13URETHRA: URETHRA 5/10/2011 14URETHRA: URETHRA In anatomy, the urethra (from Greek ourethra ) is a tube which connects the urinary bladder to the outside of the body. The urethra has an excretory function in both sexes to pass urine to the outside 5/10/2011 15 NEPHRON: NEPHRON 5/10/2011 16NEPHRON: NEPHRON 5/10/2011 17PARTS OF NEPHRON: PARTS OF NEPHRON 1) Glomerulus 2) Bowman’s capsule 3) Proximal tubule 4) Loop of Henle 5) Distal tubule 6) Collecting duct. 5/10/2011 18Slide 19: It is the basic structural and functional unit of the kidney. 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. 5/10/2011 19 IMPORTANCE OF NEPHRONIMPORTANCE OF NEPHRON: IMPORTANCE OF NEPHRON 5/10/2011 20 Its functions are vital to life and are regulated by the endocrine system by hormones such as antidiuretic hormone, aldosterone , and parathyroid hormone. The nephron carries out nearly all of the kidney's functions. Most of these functions concern the reabsorption and secretion of various solutes such ions (e.g.,sodium), carbohydrates , glucose and amino acids , glutamate) The tubes of the nephron are surrounded by cells and a network of blood vessels spreads throughout the tissue. Therefore, material that leaves the nephron enters the surrounding cells and returns to the bloodstream by a network of vessels.IMPORTANCE OF NEPHRON: The G lomerulus is a mass of thin-walled capillaries. The Bowman’s capsule is a double-walled, cup-shaped structure. The Groximal tubule leads from the Bowman’s capsule to the Loop of Henle . The Loop of Henle is a long loop which extends into the medulla. The Distal tubule connects the loop of Henle to the collecting duct. 5/10/2011 21 IMPORTANCE OF NEPHRONFORMATION OF URINE: FORMATION OF URINE If there is too much water in the blood, then it is removed and put in urine. If there is not enough water in the blood, the kidneys will not remove it. If there is too much urea or other solutes in the blood, the kidneys will remove these excess solutes. By regulating solute numbers and water volume, the kidneys normally maintain homeostasis in blood solute concentration. 5/10/2011 22Working of kidney : Working of kidney Since the kidneys control what leaves and what remains in the nephrons , they maintain the levels of water, ions and other materials nearly constant and within the limits to maintain homeostasis . Blood enters Bowman’s capsule through a tiny artery — ( the renal artery ). The artery branches to form a glomerulus . Blood pressure forces some blood plasma and small particles into the surrounding capsule — (this is called the nephric filtrate ). Large particles such as blood cells and proteins remain in capillaries. The nephric filtrate is pushed out of the capsule and into the proximal tubule . This is where reabsorption begins. 5/10/2011 23SOME FACTS ABOUT EXCRETORY SYSTEM: SOME FACTS ABOUT EXCRETORY SYSTEM At any given time, 20 % of blood is in the kidneys. Humans can function with one kidney. Antidiuretic hormone (ADH) – prevents excess water loss from kidneys Alcohol – inhibits secretion of ADH = more urine volume Aldosterone – prevents excess loss of sodium and water from kidneys Caffeine – increases rate of salt and water loss from kidneys Increased blood pressure – increase rate of water loss from kidneys. 5/10/2011 24Slide 25: 5/10/2011 25 THANK YOU You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.