Urinary System Flashcards
What is the funtional unit of the kidney?
Nephron, or uriniferous tubule (depends on how you view it
How many nephrons in the kidney?
Around 2 million
How much of cardiac output is recieved by the kidneys?
20-25%
How do the blood supplies to the lobes of the kidney relate?
They do not cross over, each stays in localized lobe
What is the hilum of the kidney?
Concave region where renal pelvis is located
What does the hilum contain?
Renal arteries, veins, lymph vessels, and nerves
Describe the renal pelvis
Cone-shaped expansion of the upper end of the ureter
What does the pelvis connect?
Major renal calyces
What is the superficial layer of kidney consisting of renal corpuscles and convoluted tubules called?
Renal cortex
What is a renal column? What do they run between?
An extension of cortical tissue. Run between adjacent renal pyramids
What are medullary rays?
Straight tubules that extend from base of renal pyramid into the cortex
What makes up the bulk of the renal medulla?
Renal pyramids, thin limbs of henle and collecting tubules
Where is the renal papillla?
At the apex of each renal pyramid
What does the renal pyramid project into? What is the name of its perforated tip?
Projects into minor caly lumen, tip is called area cribrosa
What is in the renal interstitium
Sparse connective tissue of the kidney, fibroblasts, mononuclear cells, some erythropoietin
What produces erythropoietin? Where are these cells located?
Fibroblasts, near peritubular capillaries
What is the kidney very important to in terms of blood flow?
Kidneys control blood pressure in a variety of ways
What kinds of cells are present in the medulla
Pericytes along blood vessels to loops of Henle
Interstitial cells between loops of henle, connecting ducts, and vasa recta
What do interstitial cells contain? What can they produce?
Contains elongated nuclei with lipid droplets, may synthesize medullipin I which eventually forms a vasodilator through liver modfication
Each lobe of the kidney is made up of multiple _______
Lobules
What is a renal lobule?
Area of cortex bounded on either side by interlobular artery. Nephrons all drain into the same connecting duct
What are the parts of a nephron?
Renal corpuscle, proximal convoluted tubule, loop of Henle, distal convoluted tubule
Which has longer loops of Henle, the cortical nephrons or the juxtamedullary nephrons?
The juxtamedullary nephrons
What are the nephrons for?
Exchanging water, salt, and urea
What are cortical and juxtamedullary nephrons classified by?
Location (cortex or near medulla)
Which type of nephron has peritubular capillaries?
Cortical nephrons
What do the long loops of Henle of juxtamedullary nephrons associate with (blood supply?)
Vasa recta
What kind of nephron establishes the concentration gradient of the interstitial space of the medulla?
Juxtamedullary nephrons
Which contains a greater volume, PCT or DCT?
Proximal convoluted tubule is much larger than distal convoluted tubule
What is the structural difference between DCT and PCT?
Distal convoluted tubule has apically located nuclei and no brush border
What is the epithelium of collecting tubules?
Simple cuboidal epithelium
Where are all glomeruli?
The renal cortex
What is the outer stripe of the outer medulla?
Only thick limbs and connecting ducts, no thin limbs
What is the inner stripe of the outer medulla?
Mixture of thick and thin limbs, along with collecting ducts
What area of the kidney has only thin limbs?
The inner medulla
How often would a section of blood pass through the kidney?
Approx. every 4-5 minutes
List the divisions of the renal artery down to the efferent arterioles along with where they are located in the kidney
Renal artery (hilum) -> interlobar arteries (between renal pyramids) -> arcuate arteries (along corticomedullary juntion) -> interlobular arteries (cortical tissue between medularry rays) -> afferent arterioles (enter glomerulus) -> efferent arterioles
What are the differences between typical blood circulation and renal circulation?
Kidneys pass through two sets of capillaries, one at the glomerulus, one after the efferent arteriole
What do afferent arterioles supply?
Glomerular capillaries
What do efferent arterioles supply?
Peritubular capillary network - come from afferent - give rise to peritubular capilarry netork and vasa recta depending on the nephron
Describe the course of vasa recta
Straight path into medulla and renal papilla - form capillaries, loop back and increase diameter approaching corticomedullary boundary
What does venous drainage mirror?
Arteriole blood supply
Trace venous drainage from superficial and deep cortical veins to kidney hilum
Superficial = Stellate -> Interlobular -> arcuate -> interlobar -> renal vein
Deep = Deep cortical veins -> Interlobular -> arcuate -> interlobar -> renal vein
What are the parts of the renal corpuscle?
Glomerulus and Bowman’s capsule
What is the lining of Bowman’s capsule?
Parietal - simple squamous epithelium - outer wall
Visceral – modified simple squamous epithelium composed of podocytes covering glomerular capillaries
What forms filtration slits?
Processes of podocytes wrapping around capillaries
What are the poles of the renal corpuscle
Vascular pole (afferent and efferent) and urinary pole(space continuous with proximal convoluted tubule
Where does the distal convoluted tubule come up?
Right between afferent and efferent artery
Where is the macula densa in the nephron?
The distal convoluted tubule
What do you call the capillary network inside of bowman’s capsule?
Capillary tuft
What is special about the basal lamina of the fenestrated endothelium of capillaries?
Shares basal lamina with podocytes - contribute to protection and filtration
What is another name for Bowman’s space?
Urinary space
What is the macula densa?
Specialized portion of distal convoluted tubule primarily involved in sensing sodium chloride ions
What is the brush border of the proximal convoluted tubule extremely sensitive to?
Osmolarity changes - ruffles up when kidney shuts down post mortem. Appears as debri in PCT