Excreatory system of earthworm

1. POWERPOINT PRESENTATION ON
“EARTHWORM"
Presented By:-
Abu Md. Zakariya
Class:-BSC 2nd Sem (Zoology Hons.)
Roll no:- 23
Guided By:-
Dr.Sweety Nath Barbhuiya
Asst. Professor
Department of zoology

2. TOPIC:- NEPHRIDIALSYSTEMIN EARTHWORM.

3. SYSTEMATIC POSITION:-
Kingdom: Animalia
Phylum: Annelida
Class: Clitellata
Order: Opisthopora
Family: Lumbricidae
Genus: Lumbricus

4. •The nephridia are the excretory organ of earthworm.
•Nephridia are analogous to kidneys of vertebrates.
•Nephridia are present in all segment except in first 3
segments.
•In earthworm, the nephridia functions for the removal of
excretory wastes both from blood and coelomic fluid.
•There are 3 types of nephridia based on the structure and
location:-
1. Septal nephridia.
2. Integumantary nephridia.
3. Pharyngeal naphridia.
What is Nephridia?
Types of Nephridia

5. SEPTAL NEPHRIDIA
•Septal nephridia are the longest nephridia.
•They are located in both sides of septum in each segment,behind the 15th to 2nd
last segment.
•Each inter-segmental septum possess two rows of septal nephridia numbering
80-100 on each septum.
•Septal nephridia opens into intestine.
Functions:-
Septal nephridia discharge the waste products through canal and ducts
into the lumen of the intestine.

6. INTEGUMANTARY NEPHRIDIA
•These are smallest nephridia.
•These are ‘V’ shaped in structure and are the most numerous types of
nephridia.
•Integumantary nephridia are scattered in the body wall in all segments
except in the first 2 segments and last segments.
•In each segment,there are about 200-250 integumantary nephridia.
•However,in the clitellar segments,the number is 10 times more than in
ordinary segments.
•Hence,clitellar region is also termed as the forest of nephridia.
Functions:-
They discharge nitrogenous metabolic waste products directly outside
from the body through nephridiopores.

7. PHARYNGEAL NEPHRIDIA
•They are found as paired and lie one pair in each of the 4th,5th and 6th
segment.
•They have 3 pair of nephridial canal/duct.
•The duct arise from 6th segment which opens into buccal cavity in 2nd
segment,the ducts of 4th & 5th segments opens into the pharynx in 4th
segment.
•Function:-
They discharge the waste products directly into the buccal cavity and
pharynx from where these are passe outside with undigested food through
the anus.