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
Transfer of materials from peritubular capillary plasma to the tubular lumen
Highly selective
Both active and passive transport processes at work
Occurs throughout the length of the nephron
Tubular secretion
People need only roughly _____ % of kidney tissue to live normal life
25%
The podocytes are in the ______ of the glomerular membrane
Epithelium
Transfer of material from the lumen of the tubule to the peritubular capillary plasma
Highly selective
Both active and passive transport processes
Occurs throughout the length of the nephron
Tubular reabsorption
Renal blood flow is approximately _____ mL/min
1200mL/min
Renal blood flow is about ___% of cardiac output
20%
_____ is the best index of kidney function
Glomerular filtration rate
GFR
GFR between 60 and 89
Mild kidney disease
GFR between 30 and 59
Moderate chronic renal insufficiency
GFR between 15 and 29 mL/min
Severe chronic renal insufficiency
GFR less than 15 mL/min
End stage renal failure
Fraction of plasma that filters in glomerulus
Filtration fraction
= (GFR/renal plasma flow)
Increases in ADH causes what changes in Kf and GFR?
Increased ADH causes intrarenal mesangial cells to contract which decreases surface area and decreases Kf and GFR
Angiotensin II does what to Kf and GFR
Decreases both
By decreases surface area due to the contraction of intrarenal mesangial cells
Atrial Natriuretic Peptide causes mesangial cells to _____ and causes a _____ in Kf and GFR
Relax
Increase
Pathological changes that can cause a decrease in Kf(ultrafitrate coefficient) and a decrease in GFR
Thickening of the filtration barrier (autoimmune disease)
Destruction of glomerular capillaries
Increases in urine flow cause a _______-_ in hydrostatic pressure in bowmans capsule and a ____ in GFR
An increase
Decrease
Pathologic causes of increased hydrostatic pressure in the Bowman’s capsule
Benign prostatic hypertrophy
Tumors
Kidney stones
