RENAL INTRO

Question 1

Major functions of the kidneys

Answer 1

blood and total body water volume regulation, osmolarity, electrolyte balance, acid/base balance, excretion of metabolic by-products and waste, renin-aldosterone activation, vitamin D, glucose and EPO production

Question 2

What electrolytes does the kidney work to ensure remain balanced?

Answer 2

Na+, K+, Ca2+, Mg2+, HPO4-

Question 3

Cardiovascular and Renal Systems regulation of MAP

Answer 3

ANS is fast to resolve changes in MAP by making cardiac and vascular changes, but the kidney’s regulation of blood volume is slower

Question 4

Renal cortex

Answer 4

the outer region, located just under the kidney capsule that is richly perfused with blood

Question 5

Renal medulla

Answer 5

central region, divided into an outer medulla and an inner medulla

Question 6

Renal papilla

Answer 6

the innermost tip of the inner medulla and empties into the minor and major calyces

Question 7

renal calyces

Answer 7

Major and minor calyces, are extensions of the ureter

Question 8

medullary pyramids

Question 9

renal pelvic space

Question 10

renal artery

Answer 10

where blood enter the kidney then branches into interlobar arteries, arcuate arteries, and then cortical radial arteries until it reaches the smallest artery the afferent arteriole

Question 11

Efferent arteriole

Answer 11

where blood leaves the glomerular capillaries to deliver blood to the second capillary network the peritubular capillaries

Question 12

Afferent arteriole

Answer 12

delivers blood to the first capillary network, the glomerular capillaries, across which ultrafiltration occur

Question 13

ureter

Answer 13

where urine from minor and major calyces empty into and transports urine to bladder for storage and ultimate removal

Question 14

sequence the blood flows from renal artery to renal vein

Answer 14

renal artery –> arcuate, interlobar, interlobular , segmental arteries –> afferent arteriole –> glomerulus–> efferent arteriole –> peritubular capillaries and vasa recta (for juxtamedullary nephrons) –> arcuate, interlobar, interlobular , segmental veins–> renal vein

Question 15

Glomerular capillaries

Answer 15

first capillary network that receives blood from afferent arteriole
- are bigger and more permeable to water than normal capillary beds (has a high Kf) so more fluid is filtered here than at other capillaries

Question 16

Vasa recta

Answer 16

long, hairpin-shaped blood vessels of the medulla that follow the same course as the loop of Henle; serve as osmotic exchangers to produce a more concentrated urine

Question 17

Renal corpuscle

Answer 17

blood filtering component of the nephron consisting of the glomerulus and Bowman’s capsule

Question 18

Tubular system

Answer 18

single layer of epithelial cells to allow for exchange of blood and interstitial fluid (reabsorption and secretion)

Question 19

Juxtaglomerular apparatus

Answer 19

side of the glomerulus facing distal tubule here renin is secreted from in response to perfusion of blood through the kidney

Question 20

Macula densa (of distal tubule)

Answer 20

cells of the distal tubule that respond to the increased delivered load by secreting a vasoactive substance that constricts or dilates afferent arterioles via a paracrine signaling

Question 21

Juxtaglomerular cells

Answer 21

specialized smooth muscle cells of the afferent arteriole that synthesizes renin in response to low blood flow through the kidney

Question 22

Collecting duct system

Question 23

Cortical/superficial nephrons

Answer 23

nephrons whose glomeruli are in the cortex with short Loops of Henle that typically descend only to the outer medulla
- capillaries here branch off the efferent arteriole to deliver nutrients to the epithelial cells

Question 24

Juxtamedullary nephrons

Answer 24

nephrons that have their glomeruli near the corticomedullary border with longer Loops of Henel that descend to the inner medulla and papilla
-typically have a higher GFR
- capillaries here are the vasa recta

Question 25

Capillary type in the kidneys

Answer 25

Fenestrated - allows very limited amounts of protein (are otherwise too large) in a healthy kidney

Question 26

podocyte

Answer 26

surround the capillaries of the visceral layer of Bowman's capsule, forming the filtration barrier that regulates what gets filtered from the blood into Bowman's capsule

Question 27

pedicels

Answer 27

processes from podocytes that interdigitate with adjacent podocytes to create a filtration slit for passage of smaller molecules

Question 28

Proteinuria

Answer 28

passage of proteins into the filtrate of Bowman's space - may be due to loss of negative charges of the basement membrane/filtration barrier

Question 29

Why does blood pressure remain stable at the glomerular capillaries?

Answer 29

In between two high pressure vessels (afferent and efferent arterioles) that can regulate flow - smooth muscle of these arterioles helps them alter resistance or diameter as needed

Question 30

Glomerular filtration rate (GFR)

Answer 30

volume of fluid filtered per unit time from the glomerular capillaries into Bowman's space norm= 137ml/min (180L/day)

Question 31

renal plasma flow (RPF)

Answer 31

flow rate of plasma through the kidneys per minute RPF= RBX x (1-hematocrit)= 0.687 L/min normal

Question 32

renal blood flow

Answer 32

flow rate of whole blood through the kidneys per minute - every minute the kidneys are supplied with 1.25L of blood (25% cardiac output)

Question 33

Filtration fraction

Answer 33

the proportion of plasma presented to the kidneys and filtered through the glomerulus and into Bowman's space FF= GFR/RPF

Question 34

Hydrostatic pressure (Pc)

Answer 34

the pressure exerted by blood against the wall of a capillary and is the same as the capillary blood pressure - favors filtration

Question 35

Protein osmotic/oncotic pressure

Answer 35

osmotic pressure exerted by proteins that helps pull water into the circulatory system - favors reabsorption

Question 36

Filtration constant (Kf)

Answer 36

how permeable the capillary is relative to surface area GFR= Kf x (Pgc-Pbc-[oncotic pressure of glomerular capillary])

Question 37

Starling forces on glomerular capillaries

Answer 37

at the end of the glomerular capillary, blood has been filtered, leaving behind really only protein which raises the oncotic pressure as plasma is filtered but not to the point that would favor reabsorption, just to where net filtration equals 0