Download Osmoregulation - By Dr.R.P.Singh(PGT Bio)

 Osmoregulation:-The regulation of solute
and water content in an animal body is
known as osmoregulation.
Types of osmmoregulation :
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Osmoregulation in fresh water animal
Osmoregulation in marine animal
Osmoregulation in terrestrial animals
 Osmoconformers:- osmoconformers are
the animals that do not control the osmotic
concentration of their body fluid ,but
change the osmolarity of their body fluid
according to their medium.
Many marine fishes lose water by
osmosis, drink seawater, and
excrete excess salts
Gain of water and salt
ions from food
and by drinking
seawater
Excretion of salt
ions from gills
Osmotic water loss
through gills and other
parts of body surface
Excretion of salt ions
and small amounts
of water in scanty
urine from kidneys
 Osmoregulators:- osmoregulator are
the animal that maintain an internal
osmolarity , which is different from
surrounding medium which they inhibit .
 E.g. :- protozoans & fresh water fish
Osmoregulators control water and solute
concentrations
Freshwater fishes gain water by osmosis and
tend to lose solutes
Osmotic water gain through gills
and other parts of body surface
Uptake of water and some
ions in food
Uptake of salt ions by gills
Excretion of large amounts of
water in dilute urine from kidneys
It is defined as the elimination of
metabolic wastes.
Types of excretion :Ammonotelism
Ureotelism
Uricotelism
Proteins
Nucleic acids
Amino acids
Nitrogenous bases
–NH2
Amino groups
Most aquatic animals,
including many fishes
Ammonia
Mammals, amphibians,
sharks, some bony fishes
Birds, insects, many
reptiles, land snails
Urea
Uric acid
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The process of elimination of nitrogenous waste as
ammonia is called ammonotelism.
Ammonia is readily soluble in water so it requires
more amount of water.
Ammonia is highly toxic so has to eliminated quickly.
Kidneys play a minor role in elimination of ammonia.
E.g.:-tadpoles aquatic soft bodied animals.
The process of elimination of nitrogenous waste as
urea is called ureotelism.
 It is 100,000 times less toxic than Ammonia.
 It need less water then ammonia for its
elimination.
 It is concentrated in the blood or urine.
 It is less toxic than Ammonia.
 E.g.:-Mammals, terrestrial , adult amphibian,
cartilaginous fish.
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The process of elimination of nitrogenous waste as
uric acid is known as Uricotelism.
It is very less soluble in water & those animals which
have to conserve water in their bodies evolved this
method. .
It is less toxic than ammonia & can be retained in
body.
E.g.:- land snails , insects , birds , & many reptiles.
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PROTONEPHRIDIA :- PLANARIA, ROTIFERS,
BRANCHIOSTOMA.
METANEPHRIDIA :- EARTHWORM , OTHER
ANNELIDS.
MALPHIGHIAN TUBULE :- COCKROCH , LOCUST
, GRASSHOPPER.
GREEN GLAND :- PRAWN , CRASTASIANS.
KIDNEY :- MAMMALS,
IT IS CONSIST OF : TWO KIDNEYS
 A PAIR OF URETERS
 A URINARY BLADDER
 A URETHRA
THE KIDNEYS ARE LOCATED ON EITHER SIDE OF
VERTEBRAL COLUMN, IN THE ABDOMINAL
CAVITY , ATTACHED TO DORSAL BODY WALL.
(Aorta)
(Inferi orvena cava)
Renal artery
and vein
Ureter
Bladder
Urethra
Kidney
IT IS BEAN SHAPED & MESURES ABOUT 10cm , 5cm
, 3cm IN LENGTH BREATH & THICKNESS.
IT IS CONSIST OF :
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HILUM/HILUS RENALIS
PELVIS
RENAL CORTEX
RENAL MEDULLA
RENAL PYRAMID
CALYX
Nephron is the structural & functional unit of kidney.
Renal
medulla
Renal
cortex
Renal
pelvis
PYRAMID
Ureter
It is the structural & function unit of
kidney.

Each kidney contain a million of nephron.

It contains:1.
Bowman's capsule 2. Proximal convoluted
tubule 3.distil convoluted tubule 4. Loop
of henle.
Urine collect in collecting duct where collecting
tubule opens.

Bowman’s
capsule
Renal artery
Nephron
tubule
Collecting
duct
Renal
cortex
Renal vein
Renal
medulla
To
renal
pelvis
C. ORIENTATION OF A NEPHRON WITHIN THE KIDNEY
Mechanism of urine formation
Urine formation involves three process:1. Glomerular filtration
2. Tubular reabsorbtion
3. Tubular secretion
Bowman’s capsule
Arteriole
from renal
artery
1 Proximal tubule
Glomerulus
Capillaries
Arteriole
from glomerulus's
2
3
Loop ofHenle
with capillary
network
Detailed
structure
of
nephron
Distal
tubule
Branch of
renal vein
From
another
nephron
Collecting
duct
A ultra-filtrates is filtered from the blood of glomerular capillaries into
the lumen.
-This occur through a sieve-like secretion wall formed of three layers.
1.the single layer of capillary wall
2.the basement membrane
3.single layer of epithelium wall
The process of filtration depends on two factor :1.Hydrostatic pressure difference in lumen
2.The colloidal osmotic pressure of plasma
The glomerular filtration rate is about 125ml per minute in the two
kidney
The selective transport substances across the
epithelium of the nephron from ultra filtrate to
interstitial fluid is called Reabsorbtion .
The table gives an idea about substances
reabsorbed.
Region of the tubule Substance absorbed actively Absorbed passively
1.PCT
70%Na 75% K large amount 75% of water Cl
2.Descending limb
3.Ascending limb
4.Duct collecting duct& tubule
of Ca amino acid .vitaminC
25%K some Cl
5%water
Some Na
Some Cl
Bowman’s
capsule
Proximal tubule
Distal tubule
NaCl H2O Glucose and
H2O
HCO3–
HCO3–
amino acids NaCl
Blood
Filtrate
H2O
Salts (NaCl, etc.)
HCO3–
H+
Urea
Glucose
Amino acids
Some drugs
Reabsorption
Active transport
Passive transport
Secretion
(active transport)
Some NH H+
3
drugs
and poisons
K+
CORTEX
MEDULLA
Loop of
Henle
H+
Collecting
duct
NaCl
NaCl
H2O
NaCl
Urea
H2O
Urine (to renal pelvis)
Figure 25.11
•Secretion
The nephron removes substances and adds them to
the filtrate
FILTRATION
Nephron tubule
REABSORPTION
EXCRETION
SECRETION
H2O, other small molecules
Capillary
Urine
Tubular secretion
It is a highly selective process
in which substances from
the interstitial fluid join the
fluid in the kidney tubule.
-Depending upon the availability of water in the body
kidneys can excrete hypotonic or hypertonic urine .
-Urine is concentrated by two counter current system :1. Between the two limbs of vasa rectae &
2. Between the ascending & descending limb
-It is also controlled by the hormones ADH & ANH
-when the water is plenty hypotonic urine & when it is
scarce hypertonic urine is excreted.
-Malfunctioning of kidney is reflected in changes of
composition of urine.
-Some abnormal conditions are:albuminuria –presence of albumin in urine
glycosuria – presence of glucose in urine
haematuria - presence of blood in urine
ketonuria - presence of ketone bodies
uremia - presence of excess urea
- Blood from the artery of an uremia person is taken cooled &
mixed with anticoagulant like heparin. It is put into
cellophanes tubes of the artificial kidney which is permeable
to micromolecules. Outside the cellophanes tube is dialising
fluid, which have some solute but no nitrogenous molecule.
Hence the nitrogenous molecule from within the cellophanes
flow into the dialyzing fluid following concentration
gradient . The blood coming out from the artificial kidney is
warmed to body temperature , mixed with anti heparin &
restored to a vein
Line from artery
to apparatus
Pump
Tubing made of a
selectively permeable
membrane
Dialyzing
solution
Line from
apparatus
to vein
Fresh dialyzing
solution
Used dialyzing
solution
(with urea and
excess salts)
The kidney transplant is taken from a person
which genetic make up is close to patient .
The immune system of the patient
recognizes the {non-self} cells & immune
system triggered may result in rejection of
transplant . Immunosupperasant are used
to prevent such a rejection.
Skin has two types of gland:1.
2.
Sweat gland to secrete sweat &
Sebaceous gland to secrete sebum.
-Sweat is an aqueous fluid containing NaCl,
lactic acid &amino acid.it also serve as
coolant for body.
-sebum is waxy substance containing sterols,
waxes hydrocarbons &fatty acid.
-The intergumentry system in aquatic
animals are helpful for eliminating
ammonia.
Liver is principal organ of excretion of
cholesterol, inactivated steroid
hormones, bile pigments, drugs &
some vitamin .
It secretes all these into bile,which
flows into the small intestine from
there it sent out with the faeces.
Inferior
vena cava
Hepatic vein
Liver
Hepatic
portal vessel
INTESTINE
• Lungs
excrete mainly
carbon dioxide & water
vapour.
• It sends out certain
volatile substances.