CPR 43+44 Flashcards
histology of the Proximal straight tubule (thick descending portion of LOH)?
found in the medullary ray of cortex and found in the outer medulla
shorter cells
poorly developed brush border
fewer mitochondria
thin segment of the LOH?
histology?
longer in the juxtamedullary nephrons (found in the medulla)
thin simple squamous epithelium
movement of water out and movement of ions
vasa recta
help maintain the osmotic gradient of the interstitium
the interstitium is hypertonic
loss of water
histology of distal straight tubule (thick ascending)
found in the medullary ray and the outer medulla
shorter cells with blunted brush border
reabsorption of Ca and Mg
histology of DCT
function
simple cuboidal cells
smaller cells more nuclei visible
fewer and shorter microvilli
function: reabsorb Na and bicarbonate secrete K and H secrete ammonium parathyroid regulates Ca impermeable to water high Na/K pump activity
macula densa
modified cells of the distal straight tubule
located at the vascular pole
forms part of the juxtaglomerular apparatus for BP regulation
narrower and taller cells
senses changes in Na
How does the kidney help regulate BP?
juxtaglomerular apparatus
- macula densa - osmoreceptors
- Lacis and polkissen cells
- JG cells
modified SM cells of afferent arteriole
produce renin that cleaves angiotensinogen to angiotensin I
angiotensin I to II?
I is activated to II in the pulmonary endothelial cells
potent vasoconstrictor stimulates aldosterone (secretion from adrenal cortex)
aldosterone stimulates the reabsorption of Na and secretion of K by connecting tubules and collecting ducts
connecting tubules
connects the DCT to cortical collecting duct
cortical = short
mid-cortical and JM = longer and arched
cortical collecting duct histology?
found in the medullary ray
simple cuboidal
diameter increases as it enter the medulla
medullary collecting ducts histology?
simple cuboidal transitions to simple columnar
widens as it goes from cortex to medulla
several merge to form papillary ducts (ducts of bellini)
collecting ducts: light cells and dark cells?
light cells or principal cells: most abundant (pale stain) lots of AQP-2 channels short scattered microvilli
dark or intercalated cells: fewer not present in the inner medulla secretion of H and bicarbonate microvilli at apical cytoplasm
Renal interstitium
the connective tissue of the kidney (surrounds the nephrons and vasculature)
contains fibroblasts and mononuclear cells
Excretory passages
function: transit and storage of urine
include: minor and major calyx, renal pelvis, ureter, bladder, and urethra
they all have a mucosa, muscularis, and adventitia
characteristics of transitional epithelium
- superficial
single layer of dome like cells
lots of tight junctions (impermeable to urine) - intermediate
pear shaped cells - lots of desmosomes - basal layer - stem cells
ureter
- urothelium + LP
- muscularis- 3 layers of muscle
inner longitudinal
middle circular
outer longitudinal - only seen at distal end - adventitia
Bladder
mucosa - epithelium + fibroelastic CT
muscularis:
inner longitudinal, middle circular, and outer longitudinal
adventitia or serosa
what is the male urethra consist of?
female?
male:
transitional epithelium minus fossa navicularis (strat squamous)
female:
initial - transitional epithelium
terminal - strat squamous
minimal change disease
protein molecules spill into the urine b/c of abnormalities of the capillary wall
glomerular capillary has fused foot processes
equation for GFR?
GFR = Kf x delta P
what influences GFR?
what drives GFR
filtration coefficient (Kf) and net filtration pressure
drives? Hydrostatic pressure in glomerular capillaries
hydrostatic vs oncotic pressure?
what influences oncotic pressure?
hydrostatic = pushes water oncotic = pulls water
pi or oncotic pressure is influenced by proteins (albumin)
what forces in the kidney favor filtration and favor reabsorption?
Favor filtration:
hydrostatic glomerular capillary
oncotic Bowman’s space (usually 0 when normal)
favor reabsorption:
hydrostatic bowman’s space
oncotic glomerular capillary
what is the equation for net filtration pressure or delta P?
delta P = (Pgc - Pbs) - (Pi(gc) - Pi(bs))
Significance in peritubular capillary dynamics?
Increased oncotic pressure in peritubular capillary increases absorption.
what does a change in Kf do to GFR
increased Kf = increased GFR
decreased Kf = decreased GFR
what diseases lower Kf
hypertension and diabetes
Nephrotic syndrome?
Nephritic syndrome?
what leads to this?
Nephrotic:
a kidney disorder that causes your body to excrete too much protein in your urine
Nephritic:
increases RBC release into the urine as hematuria
cause:
increase in the oncotic pressure of the bowmans capsule, thus filtration is favored
Increase in pi(bs) = more filtration, increased GFR, and edema
Urinary cholelithasis
kidney stones that lead to obstruction and dilation of the urinary system
leads to more hydrostatic pressure in the bowman’s capsule, thus opposes filtration
less filtration, decreased GFR, decreased urine output,
hydronephrosis
distention and dilation of the renal pelvis and
calyces
FF equation?
FF = GFR / RPF
normally is 20%
what is the driving force for reabsorption?
pi(c) = Oncotic pressure of peritubular capillary
renal hemodynamics? vasoconstriction?
- Flow decreases
- Pressure upstream increases
- Pressure downstream decrease
renal hemodynamics? vasodilation
- Flow increases
- Pressure upstream decreases
- Pressure downstream increases
Afferent Arteriole- Vasoconstriction
1. Decrease in hydrostatic pressure of glomerular capillaries 2. Decrease in hydrostatic pressure of peritubular capillaries 3. Decrease in renal plasma/blood flow
Afferent Arteriole Vasodilation
1. Increase in hydrostatic pressure of glomerular capillaries 2. Increase in hydrostatic pressure of peritubular capillaries 3. Increase in renal plasma/blood flow
Efferent Arteriole- Vasoconstriction
- Increase in hydrostatic pressure of glomerular
capillaries - Decrease in hydrostatic pressure of peritubular
capillaries - Decrease in renal plasma/blood flow
Efferent Arteriole- Vasodilation
- Decrease in hydrostatic pressure of glomerular capillaries
- Increase in hydrostatic pressure of peritubular capillaries
- Increase in renal plasma/blood flow
