Physiology of kidney and urinary system compatibility mode

Kabul Medical University
Physiology Department

Physiology of Kidney & Urinary
System
Prepared by: Asso. Prof.
f Dr. Mohammad Amin Frotan

1388


Function of The Kidney
z
z

Control of the level of the substances in the blood.
Filtratiosn of the blood from waste product
product.
–
–

z

Endocrine Function:
–
–
–

z
z

Exp: Urea, Createnin, Urinc Acid, Bilirubin, etc
Drugs, toxin…
Renin: Blood Pressure Control
Erythropoitin: stimulant is mainly hypoxia.
1.25 dihydroxyvitD3.

Regulation water and electrolyte balance.
Gluconeogenesis
Gluconeogenesis.






Urinary System
Physiology
Anatomophysiology
of the
Urinary System
Kidney
Pelvis
Ureteropelvic Junction
Ureter
Ureterovesical Junction
Urinary bladder
Prostate
Urethra

Anatomophysiology of the Kidney
Minor Calyces
Major Calyces

Cortex
Medulla

Pelvis

Ureteropelvic Junction
Ureter

Lobe


z
z

Renal Blood Flow
22% of Cardiac Output.
Renal Artery:
–
–
–
–
–
–
–

z

Segmental artery
Interlobar arteryy
Arcuate artery
Interlobular artery
Aff
Afferent
t artery
t
Glomerular capillaries
Efferent artery. Peritubular capillary (and vasa recta
in juxtamedullary nephrones).

The Same are Veins.


z

C
Consists
i t off :
–

THE
NEPHRONE
Glomerule:
z
z
z
z

–

Afferent Artery
Glomerular Capillary
Efferent Artery
Bowman’s Capsule

Tubule:
z
z

Proximal Convulated Tubules
Loop of Henle:
–

–

z
z

Distal Convoluted Tubules
Collecting Tubule:
–
–

z

Descending Limb
z Thick Segment

z Thin Segment
Ascending Limb
z Thick Segment
z Thin Segment

Cortical
Medullary

Collecting Duct


THE NEPHRONE


THE NEPHRONE


Nephrones
Structure of the Nephrone
p

Glumerole
Juxtaglumerolar Complex
Proximal Convoluted Tubule
Distal Convoluted Tubule
Loop of Henle

Collecting Duct
Peritubular Cappilary

REGIONAL DIFFERENCE IN NEPHRONE
STRUCTURE
z

Cortical Nephron
p
–
–

z

Short Loop of Henle
Peritubular capillary network.

Juxtamedullary Nephron (20-30%):
–
–

Long loop of Henle
Vasa recta


z
z

Juxtaglomerular
Macula
Densa Complex
Juxtaglomerular Cells

Mechanism of Function of the Nephron
Filtration
Reabsorption
Excretion


Blood Flow of the Kidneys
12-30% of Cardiac Output(5600ml/min)

Pressure in different
parts of the nephrone (mmHg)
60mmHg
g

18

10

18mmHg
13mmHg
10mmHg

0


Diameter of the holes

Glumerolar Membraen and its

Selective Permeability

Negativity of the basal memb.

Basal membrane
Endothelial

Epithelium

8 nm


Protein = 1/240

Glumerolar Filtrate and its difference to
plasma

Negative Ions

5

Positive Ions

5

No RBC

Plasma

Glumerolar Filtrate

Pressures for Glumerular Filtration

GP = + 60mmHg
GCOP= - 32mmHg
CP = +18mmHg

FP = GP – (GCOP + CP) = 10mmHg

Filtration Coefficient (Kf) = GFR/FP = 12.5ml/min
GFR = (Kf) x net FP = 125ml/min


Pressures for Reabsorption in
Peritubular Capillaries

+6mmHg
-15mmHg
+13mmHg

Net Absorption Pressure = 10mmHg


Gl
Glomerular
l Filtration
Fil
i Rate
R

Amount of glomerular filtrate/min:

Definition:
Factors Affect
the GFR:

Blood flow of the kidney
Aff. art. constriction
Eff art.
Eff.
art constriction

Glomerular Pressure
Concentration,

Importance of
GFR Regulation

GFR

GFR

Ab
Absorption
ti off unnecessary substances
b t

GFR

Excretion of necessary substances

GFR depends on diameters of afferent and efferent
arterioles
Glomerulus
Afferent arteriole

×GFR

Aff. Art. dilatation

Prostaglandins,
Kinins,
Dopamine (low
dose)

Efferent arteriole

Glomerular
filtrate
Eff. Art.
constriction

Angiotensin II
(low dose)

ØGFR

Aff. Art.
constriction

Ang
g II ((high
g dose),
),
Noradrenaline (Symp
nerves)

Eff. Art. dilatation

Angiotensin II
blockade


R i
Renin
Angiotensinogen

Aldosterone

Converting Enzyme
Angiotensin-I
Angiotensi-II

Aldosterone


Juxtaglomerular Complex