RENAL FUNCTION AND RENAL FUNCTION TEST Flashcards
it supplies blood to the kidney
renal artery
how much blood flow do kidneys receive?
25%
based on average body size of
1.73m^2
total renal blood flow
1200mL/min
total renal plasma flow
600 to 700mL/min
functions of kidney
- Maintaining homeostasis
- Excretion of waste products
- Concerned with the maintenance
of blood pressure and
erythropoiesis
it consists of eight capillary lobes referred to as capillary ducts
glomerulus
molecular weight of glomerulus
<70,000
where is the glomerulus located?
bowman’s capsule
what are the pores in capillary wall membrane called?
fenestrated
pores that increase capillary permeability but do not allow the passage of large
molecules and blood cells.
fenestrated
restriction of large molecules occurs as the filtrate passes
Basement membrane (basal lamina)
the thin membranes covering the filtration slits formed by
the intertwining foot processes of the podocytes of the
inner layer of Bowman’s capsule
Visceral epithelium of Bowman’s capsule.
necessary to overcome the opposition of pressure from the fluid from the Bowman’s
capsule and the ONCOTIC PRESSURE of unfiltered plasma protein.
HYDROSTATIC PRESSURE
this mechanism maintains the glomerular blood pressure at a relatively constant rate
Autoregulatory mechanism
Dilation of the afferent arterioles and constriction of the
efferent arterioles
BP drops
it regulates the flow of blood to and within the glomerulus.
RAAS (Renin-Angiotensin-Aldosterone System)
This system respond to changes in blood pressure and plasma sodium content
RAAS (Renin-Angiotensin-Aldosterone System)
this monitors the Renin-Angiotensin-Aldosterone System
JUXTAGLOMERULAR APPARATUS
The body cannot lose 120 mL of water-containing essential substances every
minute
TUBULAR REABSORPTION
REABSORPTION MECHANISMS
ACTIVE TRANSPORT and PASSIVE TRANSPORT
Can be influenced by the concentration of the substance being transported.
ACTIVE TRANSPORT
in active transport, where is substance to be reabsorbed must combined with that is contained in the membranes of the renal tubular cells?
carrier protein
plasma concentration at which active transport stops.
Renal threshold
Renal threshold for glucose
160 to 180 mg/dL
movement of molecules across membrane as a result of
differences in their concentration or electrical potential.
PASSIVE TRANSPORT
location of Glucose Amino acids Salts in active transport
Proximal Convoluted Tubule (PCT)
location of sodium in active transport
Proximal and Distal Convoluted Tubule (PCT/DCT)
location of water in passive transport
Proximal Convoluted Tubule(PCT)
Descending Loop of Henle
Collecting Duct
location of urea in passive transport
Proximal Convoluted Tubule (PCT)
Ascending Loop of Henle
location of sodium in passive transport
Ascending Loop of Henle
where is water removed by osmosis
descending loop of Henle
what is reabsorbed in ascending loop of henle?
sodium and chloride
a selective reabsorption process that serves to maintain the osmotic gradient of the medulla
countercurrent mechanism
where is the final concentration of the filtrate through the reabsorption of water begins
late distal convoluted tubule (and
continues in the collecting duct.)
2 MAJOR FUNCTIONS OF TUBULAR SECRETION
Elimination of waste products not filtered by the glomerulus
Regulation of acid- base balance
THIS ACTS AS BUFFER TO THE BLOOD
MAINTAINING NORMAL pH
BICARBONATE
The standard tests used to measure the filtering capacity of the glomeruli
CLEARANCE TEST
how is clearance test reported?
mL/min
