Lecture 31 3/26/24

Question 1

What are the functions of the urinary tract?

Answer 1

-water and electrolyte homeostasis
-excretion of wastes
-acid-base balance
-production of hormones

Question 2

What are the anatomical components of the kidney?

Answer 2

-capsule
-cortex
-medulla
-papillae
-pelvis
-hilus

Question 3

What are the two divisions of the renal cortex?

Answer 3

-pars convoluta
-pars radiata

Question 4

What is a lobe?

Answer 4

cortex and medulla with 1 pyramid

Question 5

What is a lobule?

Answer 5

medullary ray with associated nephrons

Question 6

What is a medullary ray?

Answer 6

-collecting ducts
-thick ascending limbs of Loop of Henle
-straight portions of proximal tubules

Question 7

What are the characteristics of canine kidneys?

Answer 7

-unipapillary
-smooth cortex

Question 8

What are the characteristics of equine kidneys?

Answer 8

-unipapillary
-2 pelvic recesses
-smooth cortex
-right kidney is heart-shaped

Question 9

What are the characteristics of feline kidneys?

Answer 9

-unipapillary
-prominent subcapsular veins
-yellow cortex

Question 10

What are the characteristics of porcine kidneys?

Answer 10

-multipapillary
-pelvis divides into 2 major calyces

Question 11

What are the characteristics of bovine kidneys?

Answer 11

-multipapillary
-multilobulated cortex
-no true renal pelvis

Question 12

What are the characteristics of avian kidneys?

Answer 12

-multilobulated
-lack discrete papillae
-hidden in deep recess along dorsal musculature
-no renal pelvis or urinary bladder

Question 13

Where do the ureters leave the kidney?

Answer 13

at the hilus

Question 14

What is the trigone?

Answer 14

ureteral orifices + internal urethral meatus

Question 15

Where is the apex?

Answer 15

cranially located, opposite the urethral meatus

Question 16

What percent of cardiac output makes up renal blood flow?

Answer 16

25%

Question 17

What are the characteristics of the nephron?

Answer 17

-functional unit of kidney
-glomerular compartment and tubular compartment

Question 18

What is the role of the interstitium?

Answer 18

bring reabsorbed molecules back to systemic circulation

Question 19

What is the role of the vasculature?

Answer 19

maintain hemodynamic homeostasis

Question 20

What are the characteristics of the embryologic development of the kidney?

Answer 20

-form from mesoderm
-3 sets of kidneys originally develop
-pronephros and mesonephros atrophy
-metanephros develops into permanent kidney

Question 21

What are the components of the metanephros?

Answer 21

-metanephric blastema
-ureteric bud

Question 22

What are the characteristics of the ureteric bud?

Answer 22

-divide via branching morphogenesis
-gives rise to collecting duct and connecting tubules

Question 23

What is required for the formation of the normal nephron?

Answer 23

interaction between ureteric bud and metanephric blastema

Question 24

What are the renal pelvis and ureters derived from?

Answer 24

ureteric bud

Question 25

What is the role of the urorectal septum?

Answer 25

grows and separates cloaca into 2 compartments

Question 26

What are the two compartments that the cloaca is divided into?

Answer 26

-urogenital sinus: gives rise to urinary bladder and urethra -anorectal canal: gives rise to rectum and anus

Question 27

What is the emptying pathway of the nephron?

Answer 27

-glomerulus and long tubule empty into duct -duct empties into pelvis

Question 28

How do cortical and juxtamedullary nephrons differ?

Answer 28

-cortical nephrons have the bulk of tubules in the renal cortex -juxtamedullary nephrons are more-so in the medulla

Question 29

What is the order of the nephron?

Answer 29

-glomerulus -Bowman's space -proximal convoluted tubule -straight portion of proximal tubule -Loop of Henle descending limb -LOH ascending thin limb -LOH ascending thick limb -distal convoluted tubule -connecting tubule -cortical collecting duct -medullary collecting duct -papillary duct

Question 30

What components of the nephron are in the cortex?

Answer 30

-renal corpuscles -proximal tubules -distal tubules -collecting ducts

Question 31

Which components of the nephron are in the medulla?

Answer 31

-Loops of Henle -collecting ducts -vasa recta

Question 32

What are the steps of urine formation?

Answer 32

-ultrafiltrate passes from glomerular capillary into Bowman's space -filtrate passes from Bowman's space into renal tubules -renal tubules empty into renal pelvis -renal pelvis empties into ureter, which leads to urinary bladder

Question 33

What percent of the ultrafiltrate is reabsorbed?

Answer 33

98%

Question 34

Which substances make up the tubular secretions?

Answer 34

-K+ -H+ -NH4+ -bile salts -drug metabolites

Question 35

What is the function of the renal corpuscle?

Answer 35

filters blood to form urinary ultrafiltrate

Question 36

What are the main parts of the renal corpuscle?

Answer 36

-glomerulus -Bowman's capsule

Question 37

Which cells are present within the renal corpuscle?

Answer 37

-podocytes -squamous cells -endothelial cells -mesangial cells

Question 38

What are the characteristics of the blood-urine barrier?

Answer 38

-blood is selectively filtered across glomerular filtration barrier to create ultrafiltrate of plasma -driven by hydrostatic and oncotic pressure -filtration impacted by molecular charge, size, and concentration

Question 39

What are the three parts of the blood-urine barrier?

Answer 39

-endothelium of glomerular capillary -glomerular basement membrane -podocytes

Question 40

What are the characteristics of glomerular endothelial cells?

Answer 40

-fenestrated -covered by glycocalyx -1-2 nuclei per capillary loop -viability requires VEGF

Question 41

What are the characteristics of the glomerular basement membrane?

Answer 41

-trilaminar -thickens with age -comprised of type 4 collagen and glycosaminoglycans -neg. charge -smooth contour

Question 42

What are the characteristics of podocytes?

Answer 42

-terminally differentiated epithelial cells -maintain structure and function of glomerulus -interdigitating foot processes attach to GBM -apical cell membrane is neg. charged -produce VEGF for endothelial cell health

Question 43

What are the characteristics of mesangial cells?

Answer 43

-maintain structural integrity of glomerular tuft -can replicate -modifies glomerular perfusion -synthesizes and breaks down ECM -produces and secretes cytokines -some phagocytic properties

Question 44

What are the characteristics of the proximal tubules?

Answer 44

-in cortex only -begin at urinary pole of renal corpuscle -convoluted and straight portions -lined by single layer of cuboidal tubular epithelial cells -abundant eosinophilic cytoplasm -absorptive -high energy demand/lots of mitochondria -activates vit. D

Question 45

Which species has lipid vacuoles in the proximal tubules?

Answer 45

cats

Question 46

What are the main components of proximal tubules?

Answer 46

-microvilli -basal striations -mitochondria