Filtration slits

Foot processes of podocytes interdigitate with one another forming filtration slits (or slit pores) that, in contrast to those in the glomerular endothelium, are spanned by slit diaphragms.

Structure

Some studies suggest that the size of the filtration slits restricts the passage of large molecules (eg, serum albumin) and cells (eg, red blood cells and platelets).^[1] Proteins that are required for the correct function of the slit diaphragm include nephrin^[2], NEPH1, NEPH2,^[3] podocin, and CD2AP.^[4]

References

^ Jarad, G.; Miner, J. H. (2009). "Update on the glomerular filtration barrier". Current opinion in nephrology and hypertension 18 (3): 226–232. PMC 2895306. PMID 19374010. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2895306. edit
^ Wartiovaara, J.; Πfverstedt, L. G. R.; Khoshnoodi, J.; Zhang, J.; Mäkelä, E.; Sandin, S.; Ruotsalainen, V.; Cheng, R. H. et al. (2004). "Nephrin strands contribute to a porous slit diaphragm scaffold as revealed by electron tomography". Journal of Clinical Investigation 114 (10): 1475–1483. doi:10.1172/JCI22562. PMC 525744. PMID 15545998. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=525744. edit
^ Neumann-Haefelin, E.; Kramer-Zucker, A.; Slanchev, K.; Hartleben, B.; Noutsou, F.; Martin, K.; Wanner, N.; Ritter, A. et al. (2010). "A model organism approach: Defining the role of Neph proteins as regulators of neuron and kidney morphogenesis". Human Molecular Genetics 19 (12): 2347–2359. doi:10.1093/hmg/ddq108. PMID 20233749. edit
^ Fukasawa, H.; Bornheimer, S.; Kudlicka, K.; Farquhar, M. G. (2009). "Slit Diaphragms Contain Tight Junction Proteins". Journal of the American Society of Nephrology 20 (7): 1491–1503. doi:10.1681/ASN.2008101117. PMC 2709684. PMID 19478094. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2709684. edit

External links

Organology at UC Davis Urinary/mammal/vasc1/vasc3 - "Mammal, renal vasculature (EM, High)
Physiology at MCG 7/7ch04/7ch04p09

Anatomy: urinary system (TA A08, TH H3.06, GA 11.1215)

Abdomen

Kidneys

Layers	Renal fascia • Renal capsule • Renal cortex (Renal column) • Renal medulla (Renal sinus, Renal pyramids, medullary interstitium) • Renal lobe • Cortical lobule • Medullary ray • Nephron

Intrarenal arteries	(Renal artery) → Segmental arteries → Interlobar arteries → Arcuate arteries → Interlobular arteries → Afferent arterioles

Renal tubule	Renal corpuscle (Glomerulus, Bowman's capsule) → Proximal tubule → Loop of Henle (Descending, Thin ascending, Thick ascending) → Distal convoluted tubule → Connecting tubule → Collecting ducts aka Duct of Belini → Renal papilla → Minor calyx → Major calyx → Renal pelvis

Intrarenal veins	Efferent arterioles → Peritubular capillaries / Vasa recta → Arcuate vein → Interlobar veins → (Renal vein)

JGA	Macula densa • Juxtaglomerular cells • Mesangium/Extraglomerular mesangial cell

Filtration	Glomerular basement membrane • Podocyte • Filtration slits • Mesangium/Intraglomerular mesangial cell • Tubular fluid

Ureters

Orifice of ureter • Adventitia • Muscular layer • Mucosa

Pelvis

Bladder	Apex • Uvula • Neck • Median umbilical ligament • Muscular layer (Trigone • Detrusor) • Mucosa • Submucosa

Urethra	Urethral sphincters (External sphincter muscle of male urethra, External sphincter muscle of female urethra, Internal sphincter muscle of urethra)

M: URI

anat/phys/devp/cell

noco/acba/cong/tumr, sysi/epon, urte

proc/itvp, drug (G4B), blte, urte