1.2.1 Glomerular Filtration Function and Renal Blood Flow I Flashcards
What are the two types of nephrons and their location within the kidney?
What type of fluid is found in the urinary space of the kidney?
Ultrafiltrate (plasma without proteins)
What are the names of the capillary beds associated with the different types of nephrons?
Juxtamedullary: Vasa recta
Cortical: Peritubular capillaries
Decribe the structure of the kidney (include medulla, the calixes, renal pelvis, cortex, ureter, pyramids, and capsule)
Through what structures must ions and small molecules filter through the glomeruli?
- Fenestrates of the endothelial cells
- Glomerular basal membrane
- Slit diaphragm b/t pedicels
What the three major types of functions of the kidney?
Homeostatic (Regulation of ECF volume, electrocyte composition, acid-base balance)
Excretory (metabolic waste products, foreign substances and toxins)
Endocrine (regulate BP, erythropoiesis, Ca++ metabolism)
What is one substance that is filtered out in the glomerular capillaries?
Insulin
What is the normal value for renal blood flow (RBF)?
1.2 L/min
What three factors help determine renal filtration
- Properties of glomerular filtration membrane
- Properties of the filtered molecules
- Forces involved in filtration
Describe the chart that plots dextran polymer size vs. filterability. How would that curve shift if the dextran was charged?
As shown in the Figure, at constant charge, filtration of dextran decreases with the molecular size. Also, for any given molecular radius, cationic molecules are more readily filtered than anionic ones.
What type of circulatory system is present in the kidney?
Portal system (two capillaries in series)
What type of charge is favored (leads to an increase) in filtration?
Cationic
What is the basic function of the glomerulus?
Filtration
Decribe the layers that seperate the capillary lumen from Bowman’s space.
Surrounding the capillary lumen their is fenestrated endothelium that is attached to a basement membrane. On the other side of the basement membrane, podocytes attach via pedicels. Between these pedicels there are filtration slits where fluid can pass through
What is the filtration pressure profile within the glomerulus of the kidney?
Compare the capillary pressures in the kidney to that of other organs.
In some pathological conditions, the negative charge of the filtration barrier is lost. How will this effect the filtration of anions?
Decribe the changes in oncotic and hydrostatic pressure as blood passes through the various stages of filtration (renal artery, afferent arteriole, glomerular capillary, efferent arteriole, peritubular capillary, intrarenal vein, renal vein)
In the analogy of a fish in a fish tank, what role does the kidney play?
It acts as both the filter and pump (which selectively removes the undesired particles
What are two important proteins involved in the slit diaphragm?
Nephrin and P-cadherin
