Glomerular Filtration Flashcards
Azotemia
Increased blood urea nitrogen (BUN)
Oliguria
Low urine output
Polydipsia
Abnormally thirst as a symptom of a disease
Hypodipsia
Insensitivity to thirst.
connected to Bowman’s capsule.
1) Major site of reabsorption of filtered fluid. 2) Distinguished by large surface area. a) Apical membrane has an extensive, non-motile brush border of microvilli which bulges out into the tubular lumen. b) Basolateral membrane has multiple infoldings of the cell membrane and basal projections. Interdigitation with neighbor cell not tight.
I. Allows for large lateral intercellular spaces or channels.
II. Mitochondria line basolateral membrane of proximal tubular cells.
Proximal tubules
Hairpin loop in this segment of tubule allows fluid moving toward the papilla in the descending limb of the loop of Henle to be influenced by the fluid moving toward the cortex in the ascending limb of the loop of Henle.
a) Configuration results in countercurrent direction of flow of the tubular fluid. b) Loops are close to each other and can influence electrolyte and water
transport in each other.
Henle’s Loop
1) Returns to cortex and makes contact with the afferent and efferent arterioles of the parent renal corpuscle.
a) Site of the JUXTAGLOMERULAR APPARATUS (JGA).
Distal tubule
Part of the nephron that is the site of the juxtaglomerular apparatus (JGA)
Distal tubule
The 3 cell types found in the juxtaglomerular apparatus
Macula densa cells
Granular cells
Extraglomerular mesangial cells
Specialized epithelial cells in the late thick ascending limb of the loop of henle/earl distal tubule
Provide information on volume, flow or sodium chloride concentration of tubular fluid to the JGA
Interdigitate w/ the other 2 cell types in the JGA
Macula densa cells
Cells of JGA
Differentiated smooth muscle cells in the walls of the afferent and efferent arteriole
Secrete RENIN
Granular cells
JGA cells that secrete RENIN
Granular cells
JGA cells
Exhibit phagocytic activity
Morphologically similar to and continuous w/ the intraglomerular mesangial cells
Communicate w/ granular cells via gap junctions
Extraglomerular mesangial cells
The distal tubule is ______ to water
Impermeable
Receives tubular fluid from distal tubules on its course from cortex to inner medulla
Site of fine tuning of tubular fluid composition which results in fine control of the extracellular fluid composition
Lined by mixed rather than homogenous cells types
Collecting tubule system
Cell types in the collected tubule system
Principal cells
Intercalated cells
Cells in the collecting tubule system that are responsive to hormones
(ADH, ANP, aldosterone)
Principal cells
Cells in the collecting tubule system that are involved with H ion secretion (alpha) or bicarbonate secretion (beta)
Intercalated cells
Vagal innervation to kidneys is _____
Absent
Sympathetic stimulation to granular cells in the afferent arteriole causes _____
Increased renin secretion
Sympathetic nervous system causes _____ to arterioles
Vasoconstriction
Sympathetic stimulation to the basement membrane of proximal tubule, loop of Henle, distal tubule, and collecting duct cause ____
Enhanced sodium reabsorption by these nephron segments
Lympathic networks drain _____ but are not seen in the _____ and ______
Cortex
Medulla
Papillae
Occurs only at glomerulus
No active transport
Physical process of essentially sieving blood
Permeability selective
Glomerular filtration
