Lecture 31: Intro Flashcards
Objectives – Identify the organs of the urinary system and the major regions of the kidney on a diagram. – Identify the regions of the nephron and describe their spatial relationships to each other – Describe the histological features of the different regions of the nephron
Kidneys do what?
filter blood
return most water and solutes to blood
release EPO and calcitrol
excrete wastes
kidney and blood ionic conp
NA, K, Ca, Cl and phsophate ions
Kidneys regulate
blood ionic comp
blood pH, osmolarity, glucose
regulate blood volume
blood pressure (through muscle cells)
glucose in urine
shouldn’t be there normally
What’s special about where kidneys are?
retroparentineal: OUTSIDE parotenial cavity… not well protected
2 major parts of nephron
corpuscle
tubule
renal corpuscle
plasma filtration
glomerulus
glomerular (Boman’s) capsule
looks like a button
glomerulus
part of corpuscle
DOES the filtration
capps where filtration happens
glomerular (Boman’s) capsule
part of corpuscle
double walled epithelial cup
collects filtrate
Renal Tubule
proximal convoluted tubule
loop of Henle (ascending and descending)
distal convoluted tubule
collecting and papillary ducts do what?
drain urine to renal pelvis and ureter
Glomerular capillaries location
between afferent and efferent arteroles
what do efferent arterioles become
peritubular capillaries and casa recta
Cortical Nephron
loops of henlle dip a little into medulla
species that are water dependent (humans)
80-85% are cortucal
mostly in cortex
Juxtameduallary Nephron
close to and in medulla
long loops of henlee
mostly deep in medulla
allow excretion of dilute or concentrated urine (depending on situation)
thick and thin portions
25-20% in usblood to kidney
recieves 25% of resting CO
function of glomerular cappilaries
filtration of blood
vasoconstrict and dialate of afferent and efferet arterioles= large changes in renal filtration
function of peritubular capilaries
carry away reabsorbed substances from filtrate
2 capillary bed types
peritubular
glomerular
nerve supply to kidney
symp vasmotor nerves reg blood flow and renal resistance
alter diameter of arterioles
nephron and collecting duct histology
single layer of epicells everywhere
histology features from function of each region
microvilli
cupodial v. simple
hormone receptors
where is Boman’s capsule
surrounding capsular space
podocytes: cover caps from visceral layer
simple sqaumous cells form parietal layer
Glomerular caps arise…
from afferent arteriols
form ball before emptying into efferent and into blood
Juxtagolmerular Apparatus (JG)
where afferent arteriole makes contact with ascending loop of henlee
macula densa
juxtaglomerular cells
macula densa
thickest part of ascending loop of henlee
juxtaglomerular cells
modified cells in arteriole
Number of nephrons
constant from birth
increase in kidney size comes from inc in SIZE of nephrons
cant be replaced
Kidney Problems
dysfuction not evident until function is less than 25% of normal
removal of one kidney=enlargment of remaining until it can filter 80% of normal rate of 2 kidneys
nephritis
drinking too much-> injure or destroy nephron
glomerular cappilaries formed…
between afferent and efferent arterioles
efferent arterioles
give rise to peritubular caps of vasa recta
vasa recta
makes conntections to tubules on opposite sides
review slide
11 and around and listen around 15 minutes
flow through cortical nephrons
glomerular (boman's) capsule proximal convoluted tubule descending LH ascending LH distal convoluted tubule
flow through JG nephron
glomerular capsuke proximal convoluted tubule descending limb of LH thin ascending limb LH thick ascending loop LH distal convoluted tubule (drains to collecting duct)
glomerular
parietal and visceral layers
viscleral layer has podocytes
fenestration of glomerular endothelial cells
prevent filtration of blood cells
allows components of blood plasma through
basal lamina of glomerulus
prevenets filtration of large proteins
slit membranes between pediceles
prevent filtration of medium sized proteins
