The quality of teaching and learning is determined not just by the quality of teachers, but also the quality of the environment where they are working. This study aims to track the motivational factors of basic education educator. The results show th
Factors affecting GFR
Factors affecting GFR (A) Changes in Kf (Glomerular capillary filtration coefficient):- Kf is a measure of the product of the hydraulic conductivity and surface area of the glomerular capillaries. • it is a product of permeability and filtration
area of the glomerular capillary membrane.
Factors affecting GFR (B) Glomerular capillary hydrostatic pressure (PGC):It is mainly depended on arterial pressure, afferent and efferent arteriolar resistant. Eg, in acute renal failure GFR declines because of fall in (PGC)
Factors affecting GFR •
Increases in glomerular capillary hydrostatic pressure (PGC) raise GFR, whereas decreases in glomerular capillary hydrostatic pressure reduce GFR.
•
Glomerular capillary hydrostatic pressure (P GC) is determined by three variables, each of which is under physiologic control: (1) arterial pressure, (2) afferent arteriolar resistance, and (3) efferent arteriolar resistance.
Factors affecting GFR 1. Increased arterial pressure tends to raise glomerular capillary hydrostatic pressure (PGC) and, therefore, to increase GFR (this effect is buffered by autoregulatory mechanisms). 2. Increased resistance of afferent arterioles reduces glomerular hydrostatic pressure and decreases GFR. Conversely, dilation of the afferent arterioles increases both glomerular hydrostatic pressure and GFR
Factors affecting GFR 3. Constriction of the efferent arterioles (mild) increases the resistance to outflow from the glomerular capillaries, this raises the glomerular hydrostatic pressure , GFR increases.
Factors affecting GFR (C) Glomerular capillary oncotic pressure (IIGC):two factors that influence the glomerular
capillary colloid osmotic pressure (1) Arterial plasma colloid osmotic pressure. (2) Filtration fraction (Conc. Pl protein). GFR is inversely proportional to IIGC. eg. Dehydration,
Hypoproteinemia
Factors affecting GFR •
(D). Changes in hydrostatic pressure in bowman’s capsule:GFR is inversely proportional to it, because it opposes the filtration, certain pathological
states
associated with obstruction of the urinary tract eg precipitation of calcium stones in urinary tract. Bowman's capsule pressure can increase markedly, causing serious reduction of GFR
Factors affecting GFR (E). Sympathetic stimulation:- All the blood vessels of the kidneys, including the afferent and the efferent arterioles, are richly innervated by sympathetic nerve fibers. •
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Strong activation of the renal sympathetic nerves can constrict the renal arterioles and decrease renal blood flow and GFR . Moderate or mild sympathetic stimulation has little influence on renal blood flow and GFR
Significance •
•
The renal sympathetic nerves seem to be most important in reducing GFR during severe, acute disturbances lasting for a few minutes to a few hours, such as those elicited by the defense reaction, brain ischemia, or severe hemorrhage. In the healthy resting person, sympathetic tone appears to have little influence on renal blood flow.
