Vertebrate Structure and Function Part 1 - Comparing Structure and Function.
The Structure and Function of a Nephron
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Transcript of The Structure and Function of a Nephron
The Structure and Function of a Nephron
A physiology mini lecture presented by: Kaylee Knowles Lydia Morrison
The Kidney!!6 General Functions!
1. Extracellular fluid volumeand blood pressure regulation.
2. Osmolarity regulation
3. Ion balance
4. pH homeostasis
5. Excretion
6. Hormone production
Anatomy of the Kidney:
THE NEPHRON
The functional unit of the kidney.
1 million nephrons in a kidney – and that never changes!
80% - cortical nephrons & 20% juxtamedullary
Filtration:
-Takes place in the renal corpuscle
-Substances flow out of the glomerular capillaries into the surrounding Bowman’s capsule
-Substances must cross three filtration barriers: -glomerular capillary endothelium -basal lamina -epithelium of Bowman’s capsule
-What drives filtration? -Hydrostatic pressure! 10 mm Hg of it!
-GFR (glomerular filtration rate) -average kidney is ~125 ml/min that’s: 180 L/day which calculates to: 60 times the kidney filters the entire blood plasma volume. so: Your little kidneys filter your entire blood plasma volume 2.5 time in an hour!!!
Go kidneys go!
Proximal tubule transport particles out of the lumen into the interstitial fluid (70% of filtrate reabsorbed)
Active or Passive Total: over 99% of
filtrate is reabsorbed
Molecules move from ECF to the nephron lumen
Active Membrane transport
protein Na+/K+ transport•Decrease secretion by competition
•Penicillin
More solute reabsorbed than reabsorbed water descending limb of
the loop of Henle: into the renal medulla
ascending limb of the loop of Henle: returns to the renal cortex
Juxtaglomerular apparatus (JGA): BP
2 cells types: principal cells: ADH and Aldosterone
receptors intercalated cells: maintain blood pH
Bowman’s capsule proximal convoluted tubule Loop of Henle distal convoluted tubule collecting duct papillary duct minor calyx major calyx renal pelvis ureter
Goodpasture (Pulmonary renal syndrome;) Autoimmune disease attacking collagen Treatment: removing blood plasma to get
rid of anti-GBM antibodies and replace it with fluid, protein, or donated plasma
Nephrogenic diabetes insipidus Acquired Tubules do not respond to ADH Treatment: anti-diuretic
Used once 85-90% of kidney function is lost Removes excess Na+, waste, and water from the body Maintains K+, Na+, and bicarbonate levels Aids in the control of blood pressure
Hemodialysis: intervenous Peritoneal: put dialysate in the peritoneal cavity
via a catheter via a machine
Charytan, D. M. (2006, November 16). Goodpasture syndrome. Medline Plus Medical Encyclopedia. Retrieved February 24, 2009, from http://www.nlm.nih.gov/medlineplus/ency/article/000142.htm
National Kidney Foundation. (2009). A to Z Health Guide: Dialysis. Retrieved February 25, 2009, from http://www.kidney.org/atoz/atozItem.cfm?id=39
Patel, P. (2008, April 14). Diabetes insipidus - nephrogenic. Medline Plus Medical Encyclopedia. Retrieved February 24, 2009, from http://www.nlm.nih.gov/medlineplus/ency/article/000511.htm
Silverthorn, D. U., Ober, W. C., Garrison, C. W., Silverthorn, A. C., & Johnson, B. R. (2007). The Kidneys. In D. Espinoza, I. Nunes, & W. Earl (Eds.), Human Physiology: An Integrated Approach (pp. 614-635). San Fransisco: Pearson Education as Benjamin Cummings.
Tortora, G. J. (2005). The Uninary System. In B. Roesch, & K. Trost (Eds.), Principles of Human Anatomy (pp. 810-). Hoboken, NJ: John Wiley & Sons.