NCERT Solutions for Class 11 Biology Chapter 19 – Excretory Products and Their Elimination
NCERT Solutions for Class 11 Biology Chapter 19- Excretory Products and their Elimination provide a comprehensive study of the process of elimination of waste products from the human body. The NCERT solutions offered here summarise the chapter and are quite useful for a quick revision. The solutions are presented in points with proper headings and subheadings so as to make learning more productive and effortless.
Chapter 19 consists of 12 exercise questions. Through these questions, you will be able to understand topics like the human excretory system, urine formation, the function of the tubules, mechanism of concentration of the filtrate, regulation of kidney function, micturition, the role of other organs in excretion and disorders of the excretory system.
Important Topics for NCERT Solutions for Class11 Biology Chapter 19- Excretory Products and their Elimination
In Chapter 19 of Class 11 Biology, you will learn that nitrogenous wastes accumulated in the body have to be eliminated. Various animals form different kinds of nitrogenous waste depending upon their habitat. The major nitrogenous wastes excreted are ammonia, urea and uric acid.
Structure of Excretory System in Humans
In humans, the excretory system consists of one pair of kidneys, a pair of ureters, a urinary bladder and a urethra.
- The nephron is the structural and functional unit of the kidney and has two portions – glomerulus and renal tubule;
- The glomerulus is a tuft of capillaries formed from afferent arterioles, fine branches of the renal artery. The renal tubule starts with a double-walled Bowman’s capsule and is further differentiated into a Proximal Convoluted Tubule (PCT), Henle’s Loop (HL) and Distal Convoluted Tubule (DCT);
- Renal corpuscle or Malpighian corpuscle is a rounded structure consisting of glomerulus surrounded by a glomerular capsule.
Formation of Urine
Urine formation involves three main processes, i.e., filtration, reabsorption and secretion.
- Filtration is carried out by the glomerulus. The glomerular blood capillary pressure facilitates filtration through three membranes.
- The Blood is filtered so finely through these membranes, that almost all the constituents of the plasma except the proteins pass into the lumen of the Bowman’s capsule. Therefore, it is considered as a process of ultrafiltration.
- About 1200 ml of blood is filtered by the glomerulus per minute to form 125 ml of filtrate in the Bowman’s capsule per minute. This is called the Glomerular filtration rate.
- JGA (JuxtaGlomerular Apparatus) a specialised portion of the nephrons, plays a significant role in the regulation of GFR.
- Urine is stored in the urinary bladder till a voluntary signal from the Central Nervous System stimulates the release.
- The process of release of urine through urethra is termed micturition.
- Excluding kidneys, lungs, liver and skin also help in the elimination of excretory wastes.
Disorders of the Excretory System
- Uremia: Accumulation of urea in the blood.
- Renal calculi: Stone or insoluble mass of crystallised salts (oxalates, etc.) formed within the kidney.
- Glomerulonephritis: Inflammation of glomeruli of the kidney.
Haemodialysis: The process of removing waste products and excess fluid from the body. Dialysis is recommended when the kidneys are not able to adequately filter the blood.
Exercise Discussion of NCERT Solutions for Chapter 19
A major portion of the exercise comprises objective questions of the type ‘Name the Following, Fill in the Blanks, True or False etc. Certain questions demand detailed but precise answers, e.g. explain the autoregulatory mechanism of GFR. The NCERT Solutions for class 11 biology chapter 19 gives comprehensive, step by step answers to such questions.
Benefits of CBSE NCERT Class 11 Biology Chapter 19 by Instasolv
To give you the ultimate opportunity to learn the varied concepts associated with the excretory system in an elaborate and easy-to-understand manner, the NCERT solutions for Class 11 biology Chapter 19 has been thoroughly prepared by the Instasolv team. We assure you that you will be able to score good marks in this chapter without much difficulty.