Structure of Nephron : NephronÂ ā§° āĻ—āĻ āύ


Structure of Nephron : Nephron ā§° āĻ—āĻ āύ


Nephron is the structural and functional unit of kidney : Nephron āĻšā§ˆāϛ⧇ āĻ•āĻŋāĻĄāύ⧀⧰ āĻŽā§‚āϞ āĻ—āĻ āύ āφ⧰⧁ āĻ•āĻžā§°ā§āϝāϕ⧰⧀ āĻāĻ•āĻ•


Parts of Nephron: 


1. Glomerulus: Network of capillaries that filters blood (ultrafiltration). : ā§°āĻ•ā§āϤ āĻ›āĻžāρāĻ•āύāĻŋ āϕ⧰āĻž āϏ⧰⧁ ā§°āĻ•ā§āϤāύāĻžāϞ⧀⧰ āϜāĻžāϞāĨ¤


2. Bowman’s Capsule: Collects filtrate (not blood, but filtered fluid). : āĻ›āĻžāρāĻ•āύāĻŋ āĻšā§‹ā§ąāĻž āĻĻā§ā§°ā§ą āϏāĻ‚āĻ—ā§ā§°āĻš āϕ⧰⧇ (ā§°āĻ•ā§āϤ āύāĻšāϝāĻŧ)āĨ¤


3. Proximal Convoluted Tubule (PCT) : Maximum reabsorption (glucose, amino acids, water, salts). : āĻ…āϧāĻŋāĻ•āĻžāĻ‚āĻļ āĻĒ⧁āύ⧰ āĻļā§‹āώāĻŖ āχāϝāĻŧāĻžāϤ āĻšāϝāĻŧāĨ¤



4. Loop of Henle : Maintains water & salt balance (creates concentration gradient). : āĻĒāĻžāύ⧀ āφ⧰⧁ āĻ˛ā§ąāĻŖā§° āϏāĻŽāϤāĻž āĻŦāϜāĻžāχ ā§°āĻžāϖ⧇āĨ¤


5. Distal Convoluted Tubule (DCT) : Selective reabsorption + secretion (ions like Kâē, Hâē). : āύāĻŋā§°ā§āĻŦāĻžāϚāĻŋāϤ āĻļā§‹āώāĻŖ āφ⧰⧁ āύāĻŋāσāϏ⧰āĻŖ āϕ⧰⧇āĨ¤


6. Collecting Duct : Final concentration of urine; water reabsorption (ADH control). : āĻŽā§‚āĻ¤ā§ā§° āϘāύ⧀āĻ­ā§‚āϤ āϕ⧰⧇ āφ⧰⧁ āĻĒāĻžāύ⧀ āĻļā§‹āώāĻŖ āϕ⧰⧇āĨ¤


7. Blood Capillaries (Peritubular capillaries) : Surround tubules and help in exchange (reabsorption & secretion). : āύāϞ⧀⧰ āϚāĻžā§°āĻŋāĻ“āĻĢāĻžāϞ⧇ āĻĨāĻžāϕ⧇ āφ⧰⧁ āĻŦāĻŋāύāĻŋāĻŽāϝāĻŧ āϕ⧰⧇āĨ¤


Functions of Nephron :


1. Filtration : Blood is filtered in glomerulus. : GlomerulusāϤ ā§°āĻ•ā§āϤ āĻ›āĻžāρāĻ•āύāĻŋ āĻšāϝāĻŧāĨ¤


2. Reabsorption : Useful substances return to blood. : āĻĒā§ā§°āϝāĻŧā§‹āϜāύ⧀āϝāĻŧ āĻŦāĻ¸ā§āϤ⧁ āĻĒ⧁āύ⧰ ā§°āĻ•ā§āϤāϞ⧈ āϝāĻžāϝāĻŧāĨ¤


3. Secretion : Extra ions & wastes added to filtrate. : āĻ…āϤāĻŋā§°āĻŋāĻ•ā§āϤ āĻĒāĻĻāĻžā§°ā§āĻĨ āĻĢāĻŋāĻ˛ā§āĻŸā§ā§°ā§‡āϟāϤ āϝ⧋āĻ— āϕ⧰āĻž āĻšāϝāĻŧāĨ¤


4. Water Balance  : Controlled mainly by hormones (ADH). : āĻšā§°ā§āĻŽā§‹āύ (ADH) āĻĻā§āĻŦāĻžā§°āĻž āύāĻŋāϝāĻŧāĻ¨ā§āĻ¤ā§ā§°āĻŋāϤāĨ¤


5. Urine Formation : Occurs in 3 steps: : Filtration → Reabsorption → Secretion : āĻ›āĻžāρāĻ•āύāĻŋ → āĻļā§‹āώāĻŖ → āύāĻŋāσāϏ⧰āĻŖ


Notes: Nephron filters blood, reabsorbs useful substances, and forms urine.: Nephron ā§°āĻ•ā§āϤ āĻ›āĻžāρāĻ•āύāĻŋ āϕ⧰āĻŋ āĻĒā§ā§°āϝāĻŧā§‹āϜāύ⧀āϝāĻŧ āĻŦāĻ¸ā§āϤ⧁ āĻļā§‹āώāĻŖ āϕ⧰āĻŋ āĻŽā§‚āĻ¤ā§ā§° āϤ⧈āϝāĻŧāĻžā§° āϕ⧰⧇āĨ¤