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excretory system

CONTENTS1. INTRODUCTION2.. NEED TO EXCRETE AMMONIA3. REMOVAL OF NITROGENOUS WAST E4. EXCRETION OF UREA5. EXCRETION OF URIC ACID6. MYSTERY BEHIND BIRD POOP7. HUMAN EXCRETION8. WOKING OF KIDNEY9. NEPHRON10. TYPES OF EXCRETION11. FORMATION OF URINE12.. MOST EFFICIENT KIDNEYS13. KIDNEY FAILURE ie HAEMODIALASIS14. GOUT15. KIDNEY STONE 16. THANKS

• 1.Excretion is the process of removing cellular wastes.

• 2.The term excretion refers specifically to the elimination of wastes produced by cellular activity.

• 3.It is not removal of undigested food material!

INTRODUCTION

All organisms produce ammonia as they metabolize nutrients (protein digestion)

Ammonia is a nitrogenous waste that is toxic and must be removed from the body

How an organism removes ammonia depends upon where it lives

Why do we need to excrete Ammonia?

(3) Uric Acid• Not very toxic because

insoluble • Evolved as an adaptation

of land animals• Many organisms try to

conserve water & excrete their Nitrogen waste as a solid! (little loss of water is involved)

• Examples: insects, reptiles, birds

EXCRETION OF URIC ACIDEXCRETION OF URIC ACID

(2) Urea: - Many land animals and some bony fish (amphibians, mammals) dilute the toxic ammonia with water.- This substance is called Urea & is filtered out by the kidneys.- The problem is they do lose water in the process!- Requires Energy

Removing Nitrogenous Waste Products

The Mystery behind Bird Poop

• Unlike mammals, birds do not urinate. • Their kidneys extract nitrogenous wastes

from the bloodstream, and excrete it in the form of uric acid.

• Uric acid has a very low solubility in water, so it emerges as a white paste.

Human Excretion

Like other animals humans have a system

that excretes Nitrogen wastes as Urea, salt, and water

Urinary System: Kidneys, ureter, urethra, and bladder

Kidneys (located in back) play important role in homeostasis –

- remove waste products from blood

- maintain blood pH

- control water content of blood

Nephrons Your kidneys are

composed of 1 million cells called Nephrons.

These long coiled tubes are where the blood is actually filtered and urine is produced

WORKING OF KIDNEY

1)Blood enters kidneys from renal artery

2)Blood is filtered by passing through millions of nephrons

3)Wastes pass through ureter to the bladder as urine

4)Clean blood returns to body through renal vein

5)Bladder stores urine and passes urine out of the body through the urethra

TYPES OF EXCRETION TYPES OF EXCRETION

►Nephron has three Nephron has three functions:functions:

1. Glomerular 1. Glomerular filtrationfiltration: : filter out water, N-filter out water, N-wastes (urea), salt, wastes (urea), salt, glucose, amino acidsglucose, amino acids

2. Tubular 2. Tubular reabsorptionreabsorption: : reabsorb materials reabsorb materials that the body still that the body still needs (food needs (food molecules, water).molecules, water).

3. Tubular 3. Tubular secretionsecretion: : collect wastes as urine collect wastes as urine and pass them to the and pass them to the bladder (urea, salts, bladder (urea, salts, other substances)other substances)

FORMATION OF URINE

MOST EFFICIENT KIDNEYS

Desert animals must be able to conserve moisture

Most terrestrial animals must drink fresh water often; however the kangaroo rat does not need to drink water very often – its kidneys absorb every little drop of water

Kidney FailureKidney FailureIf renal failure occurs,If renal failure occurs,

people must get their blood people must get their blood filtered throughfiltered through

Dialysis.Dialysis.

GOUT

Is a disease where the human body accumulates Uric acid in the joints.

Heredity, alcohol & kidney failure lead to this problem.

MADE BY:-MADE BY:-

NAVSIMRANSINAVSIMRANSINGH CLASS:-NGH CLASS:-10thA10thA

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