Chapter 7: Nephrology: Topic 1- Renal Anatomy and Physiology Flashcards
Name the 3 stages of embryonic kidney development and indicate which stage will form the definitive human kidney
- Pronephros- disappears
- Mesonephros –> BC, glomerulus, mesonephric duct
- Metanephros –> kidneys
When the mesonephric kidney degenerates, what does the cranial end of the mesonephric duct form in males?
under the influence of testosterone, it forms the ductus deferens, ejaculatory duct and seminal gland
What structure begins the formation of the definitive human kidney?
The ureteric bud, –> collecting system
Where does the definitive human kidney initially develop?
in the pelvis
The embryonic origin of the bladder and urethra is
urogenital sinus
Name 3 malformations evident in a stillborn infant that succumbed from bilateral frenal agenesis (Potter sequence)
oligohydramnios –> craniofacial anomalies, pulmonary hypoplasia, clubbed feet
What vessel blocks the ascent of a horseshow kidney?
inferior mesenteric artery
In a newborn with a patent urachus, there will be abnormal drainage of urine from
the umbilicus, via a fistula
the 3 main anatomic regions of the kidney are
cortex, medulla, hilum
Which nephrons have short loops of Henle and which nephrons have long ones?
Outer cortex, short ones: cortical nephrons
Inner cortex, long ones: juxtamedullary nephrons
Name the 3 structures, in order, through which urine will pass to reach the ureter, beginning at the apex of a renal pyramid.
minor calyx
major calyx
renal pelvis
If potter sequence develops from renal agenesis, what features are seen?
oligohydramnios–> club feet, pulmonary hypoplasia, craniofacial: flat noes, recessed chin
Failure of the allantois to obliterate embryologically can cause what problem?
Patent urachus–> leak urine via umbilicus
Name and briefly describe the 4 basic renal processes
filtration- water/ solute from G. capillary –> Bowman’s space
Reabsorption- solute/ water from lumen –> peritubular capillaries
secretion
excretion- water/ solute loss in the urine
About __ of the body mass is water and its distribution is ___ extracellular and ___ intracellular
60%
1/3
2/3
Four grams of inulin is infused into a patient and the plasma concentration of inulin is 250 mg/ ml after steady state ahas been achieved. What compartment is measured, and what is the volume of this compartment?
Extracellular volume
V = A/C amount/ concentration. 4g/.25 = 16 L
Does the tracer measure plasma, extracellular, or total body compartments?
I-albumin, Evan’s blue dye, Cr red blood cell
Plasma
Does the tracer measure plasma, extracellular, or total body compartments? Inulin, mannitol, 22Na+, sucrose
Extracellular
Does the tracer measure plasma, extracellular, or total body compartments? Heavy water, tritiated water, urea, antipyrine
Total
Under normal circumstances, ____ and ____ compounds are not filtered at the glomerular capillary
plasma proteins
lipid soluble
Define GFR and indicate the force producing it
rate fluid is filtered into Bowman’s space
Pressure in glomerular capillary (Pgc)
The equation for filtration fraction. What variable influences it directly?
FF = GFR/ RPF
Oncotic pressure in peritubular capillaries directly related to FF
What impact do sympathetics have on RPF, GFR and FF?
(affect both, but afferent more than efferent)
RPF very much down, GFR down, FF up
What impact does Angiotensin II have on RPF, GFR and FF?
(affect efferent more than afferent)
RPF down, GFR up, FF up
What is the important role of prostaglandins in the regulation of renal blood flow? Which over-the-counter compounds block prostaglandin production?
Maintain dilation of afferent arteriole
NSAIDS
Equation for clearance. The clearance of which compound is a measure of GFR? Why?
C= UV/P Urine concentration, flow, plasma concentration
Inulin; it is freely filtered and not secreted or reabsorbed
Plasma creatinine is used as a marker of renal function because it
is freely filtered, not reabsorbed. Inverse relationship between plasma creatinine and GFR
The clearance of ___ is a measure of effective renal plasma flow, and it is utilized for this measurement because if the plasma concentration is low enough, all of it is ____
PAH
secreted
Compound X is infused into a patient until it reaches a steady-state plasma concentration of 100 mg/dl. Once steady state is reached, the urine concentration of X is 2 mg/ml and urine flow is 1 ml/ min. Inulin clearance is 100 ml/min. Given this, is there net secretion or reabsorption of X? what is the rate of this reabsorption or secretion, and is the clearance of X greater than, equal to or less than GFR?
Filtered load = GFR * Px = 100 mg/min (rate solute enters nephron)
Rate of excretion = UV = 2 mg/ml * 1 ml/min
Filtered load is greater than excretion; therefore reabsorbed at filtered load - excretion = 98 mg/min
