Histology

Question 1

what type of epithelium is Bowmans capsule

Answer 1

simple squamous epithelium

Question 2

what are the 2 layers of Bowmans capule

Answer 2

parietal (outer) and visceral (inner) - podocytes

Question 3

what are the 3 layers that separate the blood from the glomerular filtrate

Answer 3

• capillary endothelium - has pores
• basal lamina
• podocytes (Bowmans capsule) -

Question 4

describe the structure of podocytes

Answer 4

have interdigitating cell processes forming filtration slits

Question 5

what is special about the basal lamina in renal corpuscle

Answer 5

• thicker than usual
• forms a major part of the filtration component

Question 6

mesangial cells

Answer 6

• scattered mesangial cells produce a connective tissue core called a mesangium
• these cells have several functions: support and removal of debris
• have contractile properties - resemble smooth muscle cells

Question 7

Question 8

what is the function of the renal corpuscle

Answer 8

production and collection of glomerular filtrate

Question 9

what is the basal lamina like in the proximal convuluted tubule

Answer 9

large BL invaginations to increase surface area

Question 10

proximal or distal convuluted tubules

Answer 10

proximal - they have an indistinct apical border

Question 11

function of the loop of Henle

Answer 11

• create hyperosmotic environment in medulla - salts lost into interstitial spaces between tubes
• permeability to ions varies in differenet areas

Question 12

describe the histology of the loop of henle

Answer 12

• simple squamous epithelium in the thin limb, with nuclei protruding into the lumen (tl)
• simple cuboidal epithelial cells in the thick limb, with abundant mitochondria (TAL)

Question 13

vasa recta

Answer 13

• thin walled blood vessels taht dip down into the medulla from cortex, and then climb back into cortex
• collectively called vasa recta
• branch from efferent arterioles
• run parallel to the loop of Henle

Question 14

proximal or distal convuluted tubule

Answer 14

distal - no brush border

Question 15

medullary rays

Answer 15

in the cortex, groups of straight tubules (straight segments of proximal and distal tubules and collecting ducts) run perpendicular to the surface of the kidney

Question 16

Answer 16

Question 17

what are the collecting ducts lined by

Answer 17

simple columnar epithelium

Question 18

describe the epithelium changes in the nephron

Answer 18

• bowmans capsule - simple squamous
• proximal convuluted tubule - simple cuboidal with brush border
• loop of Henle - simple squamous
• thick ascending loop of Henle - simple cuboidal with mitochondria
• distal convuluted tubule - simple cuboidal
• collecting duct - simple columnar

Question 19

what is the duct of Bellini

Answer 19

also known as papillary duct

Question 20

describe the collecting and papillary duct drainage

Answer 20

• medullary collecting ducts form papillary collecting ducts
• these converge to form a central duct near the apex of each renal pyramid
• the papillary duct exits the renal pyramid at the renal papilla
• renal filtrate is drained into minor calyx as urine
• major calyx etc

Question 21

what does the juxtaglomerular apparatus compose of

Answer 21

• macula densa
• juxtaglomerular cells
• extraglomerular mesangial cells

Question 22

macula densa function

Answer 22

sense sodium ions

Question 23

juxtaglomerular cell function

Answer 23

secrete renin, modified smoth muscle cells

Question 24

what are Extraglomerular mesangial cells also called

Answer 24

lacis cells

Question 25

what does urothlium line

Answer 25

also called transitional epithelium

condicting parts of urinary tract - renal pelvis onwards

Question 26

what are teh cells at the surface of the urothelium called

Answer 26

umbrella cells - domed

Question 27

what is the structure of the urothelium cells like facing the lumen

Answer 27

thickened and inflexible membrane:

• variability in thickness of cells represents different states of distension
• apical surface cells have a thickened membrane to provide an impermeable barrier

Question 28

Answer 28

urothelium

• umbrella cells
• capillary
• lamina properia
• smooth muscle

Question 29

compare the proximal and distal ureter

Answer 29

star shaped to allow expansion

Question 30

epithelium in urethra in males

Answer 30

• prostatic (bladder to prostate) - transitional
• membranous (prostate to bulb of penis) - transitional changes to stratified columnar
• penile - stratified columnar which changes to stratified squamous near the tip