Lecture 33-34: Urinary Microanatomy

Question 1

____secrete urine

Answer 1

kidneys

Question 2

_____ convey urine

Answer 2

ureters

Question 3

____ stores and discharges urine

Answer 3

bladder

Question 4

_____ discharges urine

Answer 4

urethra

Question 5

the outer layer of the kidney capsule is made up of what

Answer 5

fibroblasts and collagen fibers (protection)

Question 6

the inner layer of the kidney capsule is made up of what

Answer 6

myofibroblasts

Question 7

what encompasses the parenchyma of the kidney

Answer 7

cortex and medulla

Question 8

what makes up the renal lobe

Answer 8

renal pyramid + adjacent renal cortex + 1/2 column

Question 9

each renal lobe drains into _____

Answer 9

one minor calyx

Question 10

the renal papilla is?

Answer 10

pyramid extension into the minor calyx

Question 11

what is the area cribosa

Answer 11

surface of papilla w/ openings of papillary ducts

Question 12

what is the path of urine

Answer 12

minor calyx –> major calyx –> renal pelvis –> ureter –> urinary bladder

Question 13

what does the uriniferous tubule include

Answer 13

the nephron and collecting duct

Question 14

what is the purpose of the urinary space in the renal corpuscle?

Answer 14

conducts the ultrafiltrate to renal tubules

Question 15

what is the glomerulus composed of?

Answer 15

• fenestrated capillary bundle
• afferent arteriole (enters)
  -efferent arteriole (exits)

Question 16

what are the two layers of the glomerular capsule

Answer 16

parietal layer - simple squamous epithelium
visceral layer- layer of podocytes that covers the glomerulus

Question 17

what are pedicels

Answer 17

secondary processes of podocytes that interdigitate b/w podocytes

Question 18

what is the term for the gaps b/w pedicels

Answer 18

filtration slits

Question 19

what specialized cells are in the renal corpuscle

Answer 19

mesangial cells

Question 20

characteristics of the mesangial cells?

Answer 20

• modified smooth muscle cells
• secrete extracellular matrix (Mesangium) for support
• regulate glomerular distension (contraction)
• keep the glomerular filtration apparatus clean

Question 21

Function of the proximal tubule

Answer 21

reabsorption of ions and fluids and secretion of calcitriol

calcitriol = increases uptake of calcium and increases its concentration in blood

Question 22

histology characteristics of the proximal tubule

Answer 22

• simple cuboidal epithelium
• microvilli, irregular lumen
• lateral and basal folds - no clear cell borders
• high concentration of mitochondria, vesicles and lysosomes at the basal surface

Question 23

what is the function of the Thin loop of Henle

Answer 23

absorption of fluid by countercurrent exchange with the vasa recta, concentration of urine

countercurrent exchange = gradient-dependent transport of fluid into blood

Question 24

histology characteristics of thin loop of Henle

Answer 24

• simple squamous epithelium (thin) facilitates countercurrent exchange
• few short microvilli

Question 25

Function of the distal tubule

Answer 25

- selective secretion and absorption of ions (osmoregulation) Secretion to ultrafiltrate if high [ions] in blood Absorption if low [ions] in blood juxtaglomerular apparatus for sodium

Question 26

histology characteristics of distal tubule

Answer 26

- simple cuboidal epithelium - few short microvilli (smaller and more regular border than proximal tubule) - later and basal folds - no clear cell borders

Question 27

blood supply to kidney

Answer 27

- afferent arteriole (renal artery to glomerular capillaries) - efferent arteriole (glomerular capillaries to cortical and medullar capillaries)

Question 28

conduct urine into minor calices

Answer 28

collecting ducts

Question 29

Predominant cells of the collecting duct that are stimulated by ADH to provide water permeability

Answer 29

light cells

Question 30

cells of the collecting duct that are involved in acid-base balance. Secrete carbonate into urine to decrease blood pH. Secrete H+ into urine to increase blood pH

Answer 30

Dark cells