FILTRATION MEMB COMPLEX

 1.      FILTERING MEMBRANE COMPLEX

-          Filtration membrane is otherwise called as filtration barrier or glomerulo-capillary membrane

-          It is the membrane through which the fluid from the plasma of glomerular capillaries pass in to the Bowman’s Capsule.

Components:

1.      Capillary endothelium:

       – Fenestrated (contains pores of 70-90 nm diameter)

       – Freely permeable to water, small solutes & small proteins

2.      Basal lamina:

      – Union of glomerular capillary basement membrane & Bowman’s capsule  

          basement membrane

      – Consists of glycoproteins & mucopolysaccharides

 

      – Prevents filtration of proteins as strong negative charges are associated with  

        proteoglycans in the basal lamina

3.      Bowman’s Capsule Visceral Epithelium:

    – Formed by special cells called podocytes

    – Podocytes have finger like processes called pedicels

    – The pedicels interdigitate to cover the basement membrane & they are separated  

        by gaps called filtration slits (25 nm diameter

1.      INNERVATION OF URINARY BLADDER

            Sympathetic nerve supply (Hypogastric nerve) – T₁₂ to L₂

                     Site of supply: Trigone of bladder & internal urethral sphincter

                     Functions:

a)      Carry pain sensation from bladder

b)      On stimulation, causes relaxation of bladder & contraction of internal urethral sphincter (called as nerve of filling)

             Parasympathetic nerve supply (Pelvic nerve) – S₂, S₃ & S₄  

                     Site of supply: Trigone of bladder & internal urethral sphincter