Download MBBS Physiology Presentations 20 Excretory System Lecture Notes

Download MBBS (Bachelor of Medicine, Bachelor of Surgery) 1st Year, 2nd Year, 3rd Year and Final year Physiology 20 Excretory System PPT-Powerpoint Presentations and lecture notes

Excretory System
Functions of Kidneys

? Excretion of metabolic waste products and

chemicals

? Regulation of water and electrolyte balances
? Regulation of body fluid osmolality and

electrolyte concentrations

? Regulation of arterial pressure

Functions of Kidneys

? Regulation of acid-base balance
? Secretion, metabolism and excretion of

hormones

? Gluconeogenesis


Mesangial Cells

? Stellate cells located between endothelium

and basal lamina

? Common in between capillaries
? They are contractile
? Secrete extracellular matrix, take up

immune complexes and involved in

diseases

? They regulate GFR
Physiologic control of GFR and

Renal blood flow

? Sympathetic nervous system activation

decreases GFR

? Norepinephrine, Epinephrine and

Endothelin constricts renal blood vessels
and decrease GFR

? NO, Prostaglandins and Bradykinin

increase GFR

? Total blood flow through both kidneys is

1100 ml/min or 22% of cardiac output

? Kidneys consume twice the rate of the

brain but receives 7 times the blood flow

as brain

Tubulo-glomerular feedback mechanism