{"id":6857,"date":"2026-10-03T07:43:25","date_gmt":"2026-10-03T07:43:25","guid":{"rendered":"https:\/\/ksquareinstitute.in\/blog\/?p=6857"},"modified":"2026-10-03T07:43:26","modified_gmt":"2026-10-03T07:43:26","slug":"excretory-system-neet-pyq-analysis","status":"publish","type":"post","link":"https:\/\/ksquareinstitute.in\/blog\/excretory-system-neet-pyq-analysis\/","title":{"rendered":"Excretory System NEET PYQ Analysis: Nephron, Counter-Current and Hormones"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">Excretory Products and their Elimination is a compact Human Physiology chapter with clear facts and fixed numbers. This excretory system NEET PYQ analysis shows which parts of the nephron NTA keeps asking about, the values you must remember, and the hormone pathway that appears in paper after paper.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"432\" src=\"https:\/\/ksquareinstitute.in\/blog\/wp-content\/uploads\/2026\/10\/Excretory-System-NEET-PYQ-Analysis-Kidney-and-Nephron-1024x432.jpg\" alt=\"Excretory system NEET PYQ analysis showing a glass kidney model with an enlarged nephron loop\" class=\"wp-image-6858\" srcset=\"https:\/\/ksquareinstitute.in\/blog\/wp-content\/uploads\/2026\/10\/Excretory-System-NEET-PYQ-Analysis-Kidney-and-Nephron-1024x432.jpg 1024w, https:\/\/ksquareinstitute.in\/blog\/wp-content\/uploads\/2026\/10\/Excretory-System-NEET-PYQ-Analysis-Kidney-and-Nephron-300x127.jpg 300w, https:\/\/ksquareinstitute.in\/blog\/wp-content\/uploads\/2026\/10\/Excretory-System-NEET-PYQ-Analysis-Kidney-and-Nephron-768x324.jpg 768w, https:\/\/ksquareinstitute.in\/blog\/wp-content\/uploads\/2026\/10\/Excretory-System-NEET-PYQ-Analysis-Kidney-and-Nephron-1536x648.jpg 1536w, https:\/\/ksquareinstitute.in\/blog\/wp-content\/uploads\/2026\/10\/Excretory-System-NEET-PYQ-Analysis-Kidney-and-Nephron.jpg 2048w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">For the full physiology plan, see our <a href=\"https:\/\/ksquareinstitute.in\/blog\/human-physiology-for-neet-2027\">complete Human Physiology guide<\/a>. This article gives you the chapter-level detail.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Want to test yourself first? <a href=\"https:\/\/ksquareinstitute.com\/questions\/neet-previous-year-questions\/biology\/excretory-products-and-their-elimination\/questions\/\" target=\"_blank\" rel=\"noopener\">Solve the Excretory Products and their Elimination PYQs<\/a> for free, then use this guide to fix the gaps.<\/p>\n\n\n\n<div class=\"wp-block-rank-math-toc-block\" id=\"rank-math-toc\"><h2>Table of Contents<\/h2><nav><ul><li><a href=\"#why-this-chapter-is-reliable-marks\">Why This Chapter Is Reliable Marks<\/a><\/li><li><a href=\"#excretory-system-neet-pyq-analysis-the-repeated-question-types\">Excretory System NEET PYQ Analysis: The Repeated Question Types<\/a><\/li><li><a href=\"#nitrogenous-wastes-and-excretory-structures\">Nitrogenous Wastes and Excretory Structures<\/a><\/li><li><a href=\"#nephron-structure-what-each-segment-does\">Nephron Structure: What Each Segment Does<\/a><\/li><li><a href=\"#the-counter-current-mechanism\">The Counter-Current Mechanism<\/a><\/li><li><a href=\"#hormonal-regulation-of-kidney-function\">Hormonal Regulation of Kidney Function<\/a><\/li><li><a href=\"#worked-pyq-pattern-questions\">Worked PYQ-Pattern Questions<\/a><\/li><li><a href=\"#common-traps-in-this-chapter\">Common Traps in This Chapter<\/a><\/li><li><a href=\"#practise-every-excretory-system-pyq\">Practise Every Excretory System PYQ<\/a><\/li><li><a href=\"#conclusion\">Conclusion<\/a><\/li><li><a href=\"#\u2753-faq\">FAQ<\/a><\/li><\/ul><\/nav><\/div>\n\n\n\n<h2 id=\"why-this-chapter-is-reliable-marks\" class=\"wp-block-heading\">Why This Chapter Is Reliable Marks<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">NEET usually asks one to two questions from this chapter. Most are direct NCERT facts: which segment does what, which hormone acts where, and a few numbers.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Diagrams matter here, especially the nephron and the counter-current system. Our guide to <a href=\"https:\/\/ksquareinstitute.in\/blog\/ncert-biology-diagrams-neet-2027\">memorising NCERT Biology diagrams<\/a> helps with those. See every Biology unit in our <a href=\"https:\/\/ksquareinstitute.in\/blog\/neet-2027-biology-syllabus\">full Biology chapter list<\/a>.<\/p>\n\n\n\n<h2 id=\"excretory-system-neet-pyq-analysis-the-repeated-question-types\" class=\"wp-block-heading\">Excretory System NEET PYQ Analysis: The Repeated Question Types<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">When you sort a decade of NEET biology PYQs from this chapter, five question types cover almost everything.<\/p>\n\n\n\n<figure class=\"wp-block-table is-style-stripes\"><table class=\"has-white-background-color has-background has-border-color has-black-border-color\" style=\"border-width:2px\"><thead><tr><th>Question type<\/th><th>Frequency<\/th><th>What it tests<\/th><\/tr><\/thead><tbody><tr><td>Functions of nephron segments<\/td><td>Most frequent<\/td><td>PCT, loop of Henle, DCT, collecting duct<\/td><\/tr><tr><td>Hormonal regulation<\/td><td>Very frequent<\/td><td>ADH, renin\u2013angiotensin, aldosterone, ANF<\/td><\/tr><tr><td>Counter-current mechanism<\/td><td>Very frequent<\/td><td>Role of Henle&#8217;s loop and vasa recta<\/td><\/tr><tr><td>Nitrogenous wastes<\/td><td>Regular<\/td><td>Ammonotelic, ureotelic, uricotelic animals<\/td><\/tr><tr><td>Numbers and disorders<\/td><td>Regular<\/td><td>GFR, urine output, uremia, renal calculi<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">For a quick warm-up before the full set, try these <a href=\"https:\/\/ksquareinstitute.in\/blog\/top-5-human-physiology-questions\">five quick physiology practice questions<\/a>.<\/p>\n\n\n\n<h2 id=\"nitrogenous-wastes-and-excretory-structures\" class=\"wp-block-heading\">Nitrogenous Wastes and Excretory Structures<\/h2>\n\n\n\n<figure class=\"wp-block-table is-style-stripes\"><table class=\"has-white-background-color has-background has-border-color has-black-border-color\" style=\"border-width:2px\"><thead><tr><th>Type<\/th><th>Main waste<\/th><th>Examples<\/th><\/tr><\/thead><tbody><tr><td>Ammonotelic<\/td><td>Ammonia<\/td><td>Bony fishes, aquatic amphibians, aquatic insects<\/td><\/tr><tr><td>Ureotelic<\/td><td>Urea<\/td><td>Mammals, many terrestrial amphibians, marine fishes<\/td><\/tr><tr><td>Uricotelic<\/td><td>Uric acid<\/td><td>Reptiles, birds, land snails, insects<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Ammonia is the most toxic and needs the most water. Uric acid is the least toxic and needs the least.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Excretory structures across animals are also asked: flame cells in Platyhelminthes, nephridia in earthworms, Malpighian tubules in insects and green glands in crustaceans. These link back to our <a href=\"https:\/\/ksquareinstitute.in\/blog\/animal-kingdom-neet-pyq-analysis\">Animal Kingdom PYQ patterns<\/a> article.<\/p>\n\n\n\n<h2 id=\"nephron-structure-what-each-segment-does\" class=\"wp-block-heading\">Nephron Structure: What Each Segment Does<\/h2>\n\n\n\n<figure class=\"wp-block-table is-style-stripes\"><table class=\"has-white-background-color has-background has-border-color has-black-border-color\" style=\"border-width:2px\"><thead><tr><th>Segment<\/th><th>Key function<\/th><\/tr><\/thead><tbody><tr><td>Glomerulus and Bowman&#8217;s capsule<\/td><td>Ultrafiltration of blood<\/td><\/tr><tr><td>PCT<\/td><td>Reabsorbs 70\u201380% of electrolytes and water; all glucose and amino acids<\/td><\/tr><tr><td>Descending limb of Henle&#8217;s loop<\/td><td>Permeable to water, almost impermeable to electrolytes<\/td><\/tr><tr><td>Ascending limb of Henle&#8217;s loop<\/td><td>Impermeable to water, transports electrolytes out<\/td><\/tr><tr><td>DCT<\/td><td>Conditional reabsorption of Na\u207a and water; secretes H\u207a and K\u207a<\/td><\/tr><tr><td>Collecting duct<\/td><td>Reabsorbs large amounts of water to concentrate urine<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Numbers to remember:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Each kidney has about 1 million nephrons<\/li>\n\n\n\n<li>Glomerular filtration rate (GFR) is about 125 mL per minute, or 180 litres per day<\/li>\n\n\n\n<li>About 99% of the filtrate is reabsorbed<\/li>\n\n\n\n<li>Urine output is about 1 to 1.5 litres per day<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Juxtamedullary nephrons have a long loop of Henle that runs deep into the medulla. Cortical nephrons have a short one. Filtration depends on blood pressure, which our <a href=\"https:\/\/ksquareinstitute.in\/blog\/body-fluids-circulation-neet-pyq-analysis\">circulation chapter PYQ patterns<\/a> article covers.<\/p>\n\n\n\n<h2 id=\"the-counter-current-mechanism\" class=\"wp-block-heading\">The Counter-Current Mechanism<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The loop of Henle and the vasa recta run in opposite directions. This counter-current mechanism builds an osmolarity gradient in the medulla, from about 300 mOsmol\/L in the cortex to about 1200 mOsmol\/L in the inner medulla.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">NaCl and urea maintain this gradient. It lets the collecting duct draw water out, so humans can produce urine that is about four times more concentrated than the initial filtrate.<\/p>\n\n\n\n<h2 id=\"hormonal-regulation-of-kidney-function\" class=\"wp-block-heading\">Hormonal Regulation of Kidney Function<\/h2>\n\n\n\n<figure class=\"wp-block-table is-style-stripes\"><table class=\"has-white-background-color has-background has-border-color has-black-border-color\" style=\"border-width:2px\"><thead><tr><th>Hormone<\/th><th>Source<\/th><th>Effect<\/th><\/tr><\/thead><tbody><tr><td>ADH (vasopressin)<\/td><td>Released from the posterior pituitary<\/td><td>Increases water reabsorption in the DCT and collecting duct<\/td><\/tr><tr><td>Renin<\/td><td>JG cells of the kidney<\/td><td>Converts angiotensinogen to angiotensin I<\/td><\/tr><tr><td>Angiotensin II<\/td><td>Formed from angiotensin I<\/td><td>Raises blood pressure; triggers aldosterone release<\/td><\/tr><tr><td>Aldosterone<\/td><td>Adrenal cortex<\/td><td>Increases Na\u207a and water reabsorption<\/td><\/tr><tr><td>ANF<\/td><td>Atria of the heart<\/td><td>Lowers blood pressure; opposes the renin\u2013angiotensin system<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">A fall in blood pressure or GFR activates the JG cells. ANF does the opposite and causes vasodilation.<\/p>\n\n\n\n<h2 id=\"worked-pyq-pattern-questions\" class=\"wp-block-heading\">Worked PYQ-Pattern Questions<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Q1. Which part of the nephron is impermeable to water?<\/strong> (a) PCT (b) Descending limb of Henle&#8217;s loop (c) Ascending limb of Henle&#8217;s loop (d) Collecting duct<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Answer: (c).<\/strong> The ascending limb moves electrolytes out but does not let water follow.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Q2. What is the glomerular filtration rate in a healthy adult?<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Answer: About 125 mL per minute<\/strong>, which equals about 180 litres per day.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Q3. On which parts of the nephron does ADH act?<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Answer: The DCT and the collecting duct.<\/strong> A deficiency of ADH leads to diabetes insipidus, with large volumes of dilute urine.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Q4. Which of these animals is uricotelic?<\/strong> (a) Frog (b) Rohu (c) Pigeon (d) Human<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Answer: (c) Pigeon.<\/strong> Birds excrete uric acid to conserve water.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Q5. Which cells release renin?<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Answer: The juxtaglomerular (JG) cells.<\/strong> Renin converts angiotensinogen into angiotensin I.<\/p>\n\n\n\n<h2 id=\"common-traps-in-this-chapter\" class=\"wp-block-heading\">Common Traps in This Chapter<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Swapping the permeability of the descending and ascending limbs<\/li>\n\n\n\n<li>Saying ADH is produced by the posterior pituitary (it is made in the hypothalamus and released from the posterior pituitary)<\/li>\n\n\n\n<li>Mixing up 125 mL per minute with 180 litres per day<\/li>\n\n\n\n<li>Thinking ANF raises blood pressure<\/li>\n\n\n\n<li>Calling marine fishes ammonotelic (NCERT lists them as ureotelic)<\/li>\n<\/ul>\n\n\n\n<h2 id=\"practise-every-excretory-system-pyq\" class=\"wp-block-heading\">Practise Every Excretory System PYQ<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">This excretory system NEET PYQ analysis gives you the tables and numbers. Practice makes them automatic. Every previous year question from this chapter is available chapter-wise, free:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\ud83d\udc49 <strong><a href=\"https:\/\/ksquareinstitute.com\/questions\/neet-previous-year-questions\/biology\/excretory-products-and-their-elimination\/\" target=\"_blank\" rel=\"noopener\">Solve all Excretory Products and their Elimination NEET PYQs<\/a><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Draw the nephron once from memory before each practice set, and label what each segment reabsorbs.<\/p>\n\n\n\n<h2 id=\"conclusion\" class=\"wp-block-heading\">Conclusion<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">This chapter rewards students who know the nephron segment by segment. Use this excretory system NEET PYQ analysis to master the segment functions, the osmolarity gradient, the hormone pathway and the key numbers. Then practise until each fact comes to mind as soon as you see the question.<\/p>\n\n\n\n<h2 id=\"\u2753-faq\" class=\"wp-block-heading\">\u2753 FAQ<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Q: How many questions come from the Excretory System in NEET?<\/strong> A: Usually one to two questions, mostly on nephron functions, hormonal regulation and the counter-current system.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Q: What is the most important topic in this chapter?<\/strong> A: The functions of each nephron segment are the most tested, followed by hormonal regulation through ADH, renin, angiotensin and aldosterone.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Q: What is the normal GFR?<\/strong> A: About 125 mL per minute in a healthy adult, which adds up to about 180 litres per day.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Q: Which part of the loop of Henle is permeable to water?<\/strong> A: The descending limb is permeable to water. The ascending limb is impermeable to water but transports electrolytes.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Q: How should I revise this chapter for NEET?<\/strong> A: Use an excretory system NEET PYQ analysis to list the repeated facts, learn the nephron diagram, and solve past questions chapter-wise.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Q: Where can I practise Excretory System NEET PYQs for free?<\/strong> A: You can solve every previous year question from this chapter for free using the practice link in this article.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Excretory Products and their Elimination is a compact Human Physiology chapter with clear facts and fixed numbers. This excretory system NEET PYQ analysis shows which parts of the nephron NTA keeps asking about, the values you must remember, and the hormone pathway that appears in paper after paper. For the full physiology plan, see our [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":6858,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8,68,2],"tags":[4132,2804,4134,4129,4130,4133,2264,7,15,2328,4131,4007,4135],"class_list":["post-6857","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-study-tips","category-biology","category-neet","tag-adh","tag-class-11-biology","tag-counter-current-mechanism","tag-excretory-products-and-their-elimination","tag-excretory-system","tag-gfr","tag-human-physiology","tag-neet-2027","tag-neet-biology","tag-neet-pyq","tag-nephron","tag-previous-year-questions","tag-renin-angiotensin"],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":8}},"_links":{"self":[{"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/posts\/6857","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/comments?post=6857"}],"version-history":[{"count":1,"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/posts\/6857\/revisions"}],"predecessor-version":[{"id":6859,"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/posts\/6857\/revisions\/6859"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/media\/6858"}],"wp:attachment":[{"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/media?parent=6857"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/categories?post=6857"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/tags?post=6857"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}