The document discusses the structure and functions of the kidneys. It notes that the kidneys are paired organs located in the retroperitoneal space that are responsible for filtering blood and excreting waste from the body in urine. The kidneys contain nephrons, which are the functional filtering units. The kidneys perform critical roles in homeostasis, such as regulating blood volume, pressure, and pH. They also produce hormones and perform metabolic functions like gluconeogenesis. The kidneys filter the blood to form urine in a multi-step process involving glomerular filtration, selective reabsorption, and tubular secretion.

1. KIDNEY EXCRETION
& DETOXIFICATION
WISHAL
BUTT

2. KIDNEY:-
• Paired
• Retroperitoneal
• Partially protected by
the 11th and 12th
ribs
• Right slightly lower
due to liver
• Surrounded by renal
capsule
• Adipose capsule
• Renal fascia

3. CONTI…..
• renal arteries;
• Blood exits into the
paired renal veins.
• Each kidney is
attached to a ureter
• The nephron
• Each human adult
kidney contains
around 1 million
nephrons,
• while a mouse
kidney contains only
about 12,500
nephrons..

4. FUNCTIONS:-
1.ENDOCRINE
FUNCTION:-
kidney produces
hormones like,
 Renin
 Thrombopoietin
 Erythropoietin
 prostaglandin
site of degradation for
• parathyroid hormone
• insulin

5. 2. METABOLIC FUNCTIONS:-
Kidney perform
gluconeogenesis
during the period
of starvation.

6. 3. HOMEOSTATIC FUNCTION:-
• Regulate blood
volume &
pressure.
• Plasma ion
concentration.
• Stabilized blood
PH.
• Conserve value
able nutrients

7. 4. EXCRETORY FUNCTION:-
• The primary route in
which the body
eliminates
substances .
• The main function of
the kidney is the
excretion of body
wastes and harmful
chemicals into the
urine. uropoiesis
• The functional unit of
the kidney
responsible for
excretion is the
nephron.
• Each kidney contains

8. STEPS:-
Kidney excrete by urine formation &
release, & it consist up of following
steps.
1)Glomerular / ultra filtration
2)Selective reabsorption
3)Tubular secretion

9. FILTERATION:-
1. Renal corpuscle:
• Glomerulus –
capillaries
• Glomerular or
Bowman’s capsule
• Podocytes are
present on the
inner wall of
capsule.
• Slit pores are
present bet the
podocytes.

11. 2. FILTERATION MEMBRANE:-
filtration membrane is
composed up of…..
• Basement membrane ,
• podocytes
• Capillary endothelial
cells along with
fenestrae
NOTE; Molecules with molecular
weights greater than 60,000 (which
include large protein molecules and
blood cells) cannot pass through the
capillary pores and remain in the
blood.

12. PROCESS:-
1. Blood
afferent
arterioles
set of 50
capillaries
( glomerulus)
efferent
arterioles.
2. Filtration of
substances
occurs from
capillaries to
the bowman

13. PRESSURE:-
• Hydrostatic pressure =
Pb = 60mm Hg
• Counter pressure;
• Osmotic pressure =P°
=3o mm Hg
• Hydrostatic pressure of
filtrate = Pc = 10 mm
Hg
• Hydrostatic pressure of
I.F = Pi = 10 mm Hg
• G.F.P = Pb - ( P°+ Pc
+Pi)
• = 60 – ( 30+ 20)

14. NEPHRIC FILTERATE:-
• Also called primary urine.
• it contains glucose, water, a.a, vitamins,
ions like Na , Pt., urea , uric acid etc.
• this filtrate is isotonic to plasma in its
composition.
• 650 ml plasma passes through all the
nephrons in both the kidneys per minute
called RENAL PLASMA FLOW.
• glomerular filtrate rate (GER) 125ml /min
get filtrated.
• Per day filtrate range is 150 to 180 litre.
• Average value is 172 litre.

15. SELECTIVE REABSORPTION:-
Absorption of substance takes place
as;
High threshold
substances
Low threshold
substances
Non-threshold
substances
completely or
almost
completely
absorbed
absorption is v v
v small
do not absorb at
all
e.g. Glucose ,
amino acids.
e.g. Urea e.g. hipppuric
acid , creatin.

16. PEROXIMAL CONVOLUTED
TUBULES:-
1. Brush boarder
epithelium cell have
micro villi.
2. Increased surface area
for absorption.
3. Cells have many
mitochondria, because
more energy is required
for active transport.
4. glucose 100% , a.a
100% , sodium 70% ,
potassium 75% ,
(active).
5. Water ( osmosis)
6. Little urea , chloride
ions ( passive).

17. DESCENDING LIMB:-
• Squamous cells
epithelium
• Thinner walls
• only permeable
to water
• Impermeable to
sodium &
chloride ions.

18. ASCENDING LIMB:-
• Lined with
cuboidal
epithelium
cells
• Thicker walls
• Impermeable
to water
• Absorption of
sodium ,
chloride ,
bicarbonate
ions occurs

19. DISTAL CONVOLUTED
TUBULES:-
• Lined with cuboidal
epithelium
• few micro villi are
present
• absorption of Na+ , Pt.+
ions
• opens in the collecting
duct
• There the fluid will be
called as urine.
• 95% water absorption
• Wall sensitive to the

20. 3. TUBULAR SECRETIONS:-
• Waste of peritubular
capillaries is
absorbed by the PCT
& DCT.
• PCT carry both
nephric filtrate &
peritubular waste.
• PCT absorbes the H+
, NH4 , creatin,
hippuric acid , drugs.
• DCT abcorbs the H+,
HCO-³ K+ , NH4 rtc.

21. PRODUCT:-
Urine
i.5 to 1.8 litre
excretion per
day.
Enters in
ureters,
urinary
bladder & then
in urethra.

22. DETOXIFICATION:-
• Detoxification is the body’s
process of removing toxic
substances.
• Detoxification is not a food,
or diet, or a pill - it is an
ongoing, VITAL process that
your body does (all on its
own) in order to survive.
• It happens 24/7, 365 days of
the year. Not just for a few
days or weeks prescribed to
“do a detox”.
• Your main detoxification
organs are the liver and
kidneys.
• The bowels and urinary tract
are extensions of these
organs as wastes exit your
body.

23. 1.Regulating the body’s pH, or acid-
alkaline :-
even small variances in pH can
result in death

24. BLOOD FILTRATION:-
Once the kidneys filter the blood, waste products are
excreted in urine.
if the kidneys can’t do their job properly, waste can re-
circulate in the blood or become stored in the body,
leading to all sorts of nasty symptoms.
The kidneys can become damaged through toxic overload,
excess alcohol, high blood pressure, some medications
and chemotherapy. Unlike the liver, it does not
regenerate.
Dialysis is used when kidneys are severely damaged.
Protection and prevention is the best form of defense.
the kidneys also help control excessive blood glucose and
mineral imbalances.
They excrete wastes from muscle metabolism and urea from
protein

26. DISEASES:-
• Kidney stones
• Accumulations of toxins
• Glomerulonephritis,
• Polycystic disease