Renal Mod 1 Flashcards
2 capsules of the kidney
- renal capsule - surrounds each kidney
2. renal fascia - surrounds kidney and fatty mass
list the gross anatomy of the kidneys
- capsules
- cortex
- medulla
- renal pyramid
- minor calyces
- major calyces
- renal pelvis
- ureter
what does the cortex include
- glomeruli
2. proximal and distal portions of tubules
what is the medulla of the kidneys
straight segments of proximal and distal tubules
what is the renal pyramid
functional arrangement for collection
-includes the renal papilla
what is the renal papilla
the apex of the pyramid which drains into the minor calyces
what are minor calyces
collect urine from renal pyramids
what are the major calyces
collect urine from 2-3 minor calyces
what is the renal pelvis
- collects urine from major calyces
2. funnel shaped duct that becomes continuous with the ureter
what is the ureter
smooth muscle tube
drains urine from renal pelvis and descends to the bladder
how long is the ureter
25-35cm long
three regions of constriction of the ureter
- junction of renal pelvis and ureter (ureteropelvic junction)
- as ureter passes over pelvic brim
- as the ureter enters the bladder
clinical importance of ureter constriction regions
potential for kidney stones to be lodged
what facilitates flow of urine into the bladder
the smooth muscle that the calyces, renal pelvis and ureteres all contain
each lobe of the kidney has?
pyramid and cortex surrounding the pyramid
what is a nephron
functional unit of the kidney for formation of urine
how many nephrons do kidneys have
1.2 million per kidney
types of nephrons
- superficial cortical nephrons (85% of total nephrons) - extend partially into the medulla
- mid-cortical nephron - short and long loops
- juxtamedullary nephron - (12% of total nephrons) - extend deep into medulla
which type of nephron is responsible for urine concentration
juxtamedullary nephrons
regions of the nephron
- renal corpuscle
- PCT
- Loop of Henle
- DCT
- Collecting duct
function of renal corpuscle
site of filtration
renal corpuscle is formed by?
glomerulus
Bowman’s capsule
mesangial cells
what is the function of glomerulus
site of capillary filtration
what is the glomerulus formed by?
glomberular capillaries that extend into Bownman’s capsule
what is the glomeruluar filtration membrane
capillary wall
serves as filtration
three layers of glomerular filtration membrane
- capillary endothelium - fenestrated capillary wall
- basement membrane - negative charge which plays role in filtration
- capillary epithelium - foot like projections that form matrix of filtration slits
another name for capillary epithelium
podocytes
blood supply to the glomerulus
- afferent arteriole
- efferent arteriole
- juxtaglomerular apparatus (JGA)
function of afferent arteriole
regulated flow of blood into glomerulus to optimize filtration
function of efferent arteriole
glomerulus capillaries drain into efferent arteriole
-blood then travels to peritubular capillaries
importance of blood flowing from efferent arteriole to peritubular capillaries
allows reabsorption and secretion along the tubules of the nephrons
what makes up the JGA
juxtaglomerular cells + macula densa
where are juxtaglomerular cells located
adjacent to afferent glomerular arteriole
what is the macula densa
- cells in distal convoluted tubule located adjacent to afferent and efferent glomerular arterioles
- macula densa cells function as sodium-chloride receptors
JGA regulates what?
renal blood flow
glomerular filtration
renin secretion
what are mesangial cells
matrix of smooth muscle and phagocytic cells
located bw glomerular capillaries and Bowman’s capsule
functional role in regulating filtration
what is the Bowman’s capsule
collects filtrate from glomerular capillaries
what is the space inside the Bowman’s capsule
Bowman’s space
what is the PCT
proximal convoluted tubule
- continuation from Bowman’s capsule
- 15mm long, single layer of cells along wall with microvilli (brush border) along the lumen
function of microvilli in PCT
provide large surface area for reabsorption
function of PCT
major site of sodium reabsorption (and other substances) as filtrate travels through tubules
Loop of Henle composed of?
composed of descending and ascending loops
functional characteristic of Loop of Henle depends on what?
function varies by location
2 locations of Loop of Henle
- nephrons located near medulla (juxtamedullary nephron)
2. nephrons in cortical area (superficial cortical and mid cortical nephrons)
function of Loop of Henle - nephrons located near medulla
Loop of Henle extends deep into the medulla - concetrates urine
function of Loop of Henle - in cortical area
Loop of Henle - short and only partially extend into medulla - doesn’t play role in concentrating urine
location of DCT and what it stands for
distal convoluted tubule
-begins at macula densa and end at connection to collecting duct
function of DCT
- early DCT - continues to dilute filtrate as reabsorbs sodium
- late DCT - begins to concentrate the fluid as it enters collecting duct