INSECT

1
INSECT EXCRETION
2
Principal Organs of Excretion
Malpighian tubules
nephrocytes
rectal pads
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Excretory Organs - Malpighian tubules
4
Excretory Organs - Malpighian tubules
distal
honeycomb border
Secretory region
lumen
brush border
Absorbtive region
proximal
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Excretory Organs - Malpighian tubules
Honey- comb border
Brush border
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Excretory Organs - Nephrocytes
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Excretory Organs - Rectal pads
Rectal pads
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Nitrogenous Products
NH2 CO NH2
O C
H N
HN
C
NH3 Ammonia
CO
OC
C
N H
N H
CO
Urea
Uric Acid
Toxicity
9
Removal of wastes
10
Removal of wastes
Brush border
Urea
Precipitates as uric acid crystals or urate
excrete H20 base
pH 7.3 - 7.5
pH 6.5
Honeycomb border
H20 to hemocoel
H20 to hemocoel
Uric acid crystals eliminated
11
Removal of wastes
Cryptonephritic systems
12
Osmotic pressures (expressed as equivalent
solution of NaCl (mEq/l))
AQUATIC
13
Removal of wastes
Storage Excretion
Stored as uric acid in fat body
14
Sources of water gain
fog
eating
drinking