Renal histology

Question 1

What are the homeostatic functions of the kidneys?

Answer 1

Excretion of metabolic waste and foreign substances through urine
Fluid and electrolyte balance
Metabolic acid-base balance
Production/modification of hormones for BP
Calcium and potassium homeostasis
Production of EPO

Question 2

What are the parts of the renal corpuscle of the nephron?

Answer 2

Bowman’s capsule
Glomerulus

Question 3

What are the parts of the nephron’s tubule system?

Answer 3

PCT
Thick descending limb/proximal straight tubule
Loop of Henle with its thin ascending and descending parts
Thick ascending limb
DCT
Collecting duct

Question 4

What are the layers of the CT capsule covering the kidney?

Answer 4

Outer layer of fibroblasts and collagen
Inner layer of myofibroblasts

Question 5

What defines a renal lobe?

Answer 5

Single renal pyramid with its overlying cortex

Question 6

What defines a renal lobule?

Answer 6

In cortex
Single medullary ray and the cortical labyrinth on either side

Question 7

What parts of the nephron are found in the cortical labyrinth?

Answer 7

Renal corpuscle
PCT
DCT

Question 8

What parts of the nephron are found in the medullary rays?

Answer 8

Thick descending
Thick ascending
Collecting duct

Question 9

What parts of the nephron are found in the outer medulla?

Answer 9

Parts of thick descending and thick ascending
Thin ascending and descending
Collecting duct
Loop of Henle of cortical nephrons

Question 10

What parts of the nephron are found in the inner medulla?

Answer 10

Loop of Henle of juxtamedullary nephrons
Collecting duct

Question 11

What are the layers of the Bowman capsule?

Answer 11

Parietal - squamous epithelium
Visceral - podocytes

Question 12

What are histological features of podocytes?

Answer 12

Primary process that embrace capillaries
Secondary foot processes/pedicels connecting the primary processes and bound to GBM with fine filaments

Question 13

What is the cell adhesion molecule in filtration slit membrane and its function?

Answer 13

Nephrin
Connects actin filaments with adjacent foot processes, which can widen slits

Question 14

What are the layers of the glomerular basement membrane?

Answer 14

Lamina rara interna
Lamina densa
Lamina rara externa

Question 15

What is the name given to mesangial cells located outside the renal corpuscle?

Answer 15

Lacis cells

Question 16

What are the functions of mesangial cells?

Answer 16

Support glomerular capillary loop system
Phagocytosis
Secrete cytokines to repair damage

Question 17

What protein is secreted by the thick segments of the loop of Henle?

Answer 17

Uromodulin

Question 18

What is the function of uromodulin?

Answer 18

Role in preventing calcium crystallization
Antipathogenic agent

Question 19

What thin limp of the loop of Henle is impermeable to water, but permeable to salts?

Answer 19

Thin ascending limb

Question 20

What water channels are found in the thin descending limb?

Answer 20

Aquaporin 1 channels

Question 21

What is the epithelium of the DCT?

Answer 21

Cuboidal epithelium with extensive basal and lateral interdigitations
Less-formed microvilli

Question 22

What are the two types of cells liming the collecting tubules?

Answer 22

Principal light cells
Intercalated dark cells

Question 23

Where are renin producing cells located?

Answer 23

Juxtaglomerular apparatus, in the walls of the afferent arteriole

Question 24

Where is the macula densa of distal tubule located?

Answer 24

Juxtaglomerular apparatus

Question 25

What are the layers of the walls of the excretory passages?

Answer 25

Mucosa - urothelium and lamina propia
Musculosa - inner longitudinal and outer circular
Adventitia - fibroelastic

Question 26

What are the characteristics of transitional epithelium/urothelium?

Answer 26

Stratified
Large dome shaped cells
Modified apical membrane with plaques and fusiform vesicles to accommodate stretch

Question 27

What is the additional layer found in the wall of the ureters?

Answer 27

Middle circular layer of smooth muscle
Some serosa in posterior