EXCRETION IN AN ORGANISM

LIFE PROCESS - EXCRETION

INTRODUCTION

All the animal's need to excrete toxic material from the body and for this they have to perform some process so in common we can say that excretion is the process of removing waste or harmful metabolic product from the body is called excretion.

TYPES OF EXCRETION

On the basis of waste product excreted by the organism the excretion can be of following types:-

  1. AMMONOTELISM :- 

• It's the elimination of waste mainly in the form of Ammonia. 
• Those animals, which excrete ammonia as the main nitrogenous waste, are called as ammonotelic animals.
• Ex :- Amoeba.

  2.  UREOTELISM :- 

• It's the phenomenon of elimination of waste, mainly in the form of urea. 
• Those animal which excrete in the form of urea as the main nitrogenous waste, are called as Ureotelic animals. 
• Ex :- Mammals.

  3.  URICOTELISM :- 

• It's the phenomenon of elimination of waste, mainly in the form of uric acid. 
• Those animal which excrete in the form of uric acid as the main nitrogenous waste, are called as Uricotelic animals. 
• Ex :- Bird's.

EXCRETION IN HUMAN BEINGS

• Human beings are the terrestrial animals. So, urea is the main excretory waste.
• The main organs which performed in excretory system are:-

1. A pair of Kidney
2. A pair of ureter
3. Urinary Bladder
4. Urethra

KIDNEY

• This is the main excretory structure of human being.
• This is light brown bean shaped like structure.
• They are located in the abdominal cavity on dorsal side.
  
  
• Its measure about 10cm X 5cm X 3cm.
• Its weigh is about 125 to 170 gm. 
• Each kidney have a 1 million hairpin like structure called as Nephron.

NEPHRON

• It's the functional unit of Excretory system 
• They serve to filter the blood and form urine.
• The nephron show following part's :- 

1. Bowman's Capsule :- It's the starting cup like structure and they contain bunch of blood capillaries called as Glomerulus

2. Convoluted Tubule :- The tubular part of nephron is coiled and it's called as convoluted tubule. it has two reason's they are :-

  a) Proximal Convoluted Tubule (PCT)

  b) Distal Convoluted Tubule (DCT)

3. Henle's Loop :- It's a long turn hair pin tubule like structure.

4. Collecting Duct :- It's the large duct that receive the tubular filterate (urine) from DCT of many nehron. many collecting duct comes together and drain it's urine into Pelvic. This Pelvic connected to the Ureter.

URETER 

• A Ureter is a long tube like structure which connect kidney to the Urinary bladder.

URINARY BLADDER

• It's a inverted pear shape like structure in which urine is collected drop by drop when this bladder full a process performed called as Micturition process in which there is the sensation to excrete urine.

URETHRA

• It's the opening where the urine passed out from the human body.