Mnemonics: Excretory Products & their Elimination | Biology Class 11 - NEET PDF Download

Let's learn the complex parts and processes of kidney by interlinking it with our daily words and never ever forgetting it again.

Types of Excretion Processes

Mnemonic: "All Urea Ultimately Evolves"

• All - Ammonotelism: Excretion of ammonia (e.g., bony fish, amphibians).
• Urea - Ureotelism: Excretion of urea (e.g., mammals, amphibians).
• Ultimately - Uricotelism: Excretion of uric acid (e.g., birds, reptiles).
• Evolves - Evolutionary Adaptation: Terrestrial animals produce less toxic forms like urea or uric acid for water conservation.

Types of Excretory Organs and Examples

Mnemonic: "Please Never Make Green Plants"

• Please - Protonephridia (e.g., Planaria): For osmoregulation in flatworms.
• Never- Nephridia (e.g., Earthworm): Remove nitrogenous wastes and maintain fluid balance.
• Make - Malpighian Tubules (e.g., Cockroach): For osmoregulation and nitrogen waste elimination in insects.
• Green - Green Glands (e.g., Prawns): Excretion in crustaceans.
• Plants- Plants: Use transpiration, guttation, and excretion through leaves for waste elimination.

Parts of the Kidney

Mnemonic: "Can Medics Handle Calm Patients?"

• Can  - Cortex: Outer layer containing glomeruli and convoluted tubules.
• Medics - Medulla: Inner region with pyramids and loop of Henle.
• Handle - Hilum: Entry/exit for ureters, blood vessels, and nerves.
• Calm - Calyces: Funnel-shaped projections leading to the renal pelvis.
• Patients - Pelvis: Collects urine and passes it to the ureter.

Steps of Urine Formation

Mnemonic: "Good Rabbits Swim"

• Good - Glomerular Filtration: Ultrafiltration of blood in the glomerulus.
• Rabbits - Reabsorption: Active/passive absorption of nutrients, water, and ions in the tubules.
• Swim - Secretion: Elimination of H+, K+, and ammonia into the filtrate for pH and ionic balance.

Counter Current Mechanism

Mnemonic: "Henle's Loop Regulates Salts"

• Henle's Loop - Henle's Loop: Creates a gradient via descending (water permeable) and ascending limbs (impermeable to water, salt transport).
• Loop - Loop of Vasa Recta: Parallel capillaries help in exchange and retention of salts (NaCl and urea).
• Regulates - Regulation: Ensures concentrated urine with osmolarity up to 1200 mOsmol/L.
• Salts - Salts and Urea: Contribute to the osmotic gradient in the medulla.

Role of Other Organs in Excretion

Mnemonic: "Love Liver, Skin, and Sweat"

• Love - Lungs: Remove CO₂ and water vapor.
• Liver- Liver: Excretes bile pigments (bilirubin and biliverdin), drugs, and cholesterol.
• Skin - Skin: Eliminates salts, urea, and lactic acid via sweat.
• Sweat - Sebaceous Glands: Remove sterols and hydrocarbons through sebum.

Disorders of the Excretory System

Mnemonic: "U Really Shouldn't Get Kidney Glitches"

• U - Uremia: Accumulation of urea in blood due to kidney failure.
• Really - Renal Calculi: Kidney stones formed by crystallized salts.
• Shouldn't - Stone Formation: Includes oxalate stones causing pain and obstruction.
• Get - Glomerulonephritis: Inflammation of glomeruli, impairing filtration.
• Kidney - Kidney Failure: Treated by dialysis or kidney transplantation.
• Glitches - Glycosuria and Ketonuria: Presence of glucose and ketone bodies in urine, indicative of diabetes.