L17 - kidney and urinary histology

Question 1

what are medullary rays ( or pyramids )

Answer 1

bundles of collecting tubules/ducts

Question 2

function of medullary rays

Answer 2

drain nephrons

Question 3

what is a lobe

Answer 3

medullary pyramid and the region of cortex it connects to

Question 4

what is the functional unit of the kidney

Answer 4

nephron (glomerulus to ureter)

renal corpuscle and renal tubule

Question 5

what does the renal corpuscle consist of

Answer 5

glomerulus and bowmans capsule

Question 6

what does renal tubule consist of

Answer 6

PCT
LOH
DCT
CT

Question 7

where is the renal corpuscle

Answer 7

cortex

Question 8

is the afferent or efferent arteriole bigger and which direction do they take the blood

Answer 8

afferent biggest

afferent towards glomerulus efferent away

Question 9

does PCT / DCT / CT have the biggest lumen

Answer 9

CT

Question 10

what cells line the bowmans capsule

Answer 10

parietal cells

Question 11

what are the 3 layers of the glomerular filter

Answer 11

1. capillary endothelium (fenestrated)
2. glomerular basement membrane (thick)
3. podocytes

Question 12

describe podocytes

Answer 12

branching cells that go from
primary - secondary - tertiary - pedicels
which wrap around the BM

Question 13

what are pedicels

Answer 13

finger like projections of podocytes with gaps in-between called filtration slits

Question 14

role of glomerular basement membrane

Answer 14

prevents large material crossing into filtrate

contains -ve proteins which repel other -ve proteins in the plasma (which is most proteins)(minimising protein lost into filtrate)

Question 15

order of nephron

Answer 15

afferent arteriole 
glomerulus 
bowmans space
PCT
LOH(thin descending -thin ascending -thick ascending) 
DCT
CT 
CD

Question 16

describe PCT epithelium

Answer 16

simple tall columnar with tall microvilli

Question 17

describe DCT epithelium

Answer 17

simple cuboidal no microvilli

Question 18

what is found in PCT epithelium

Answer 18

microvilli
vesicles (transport of absorbed material to capillary side)
mitochondria
lysosomes

Question 19

how does epithelium change from PCT through the LOH

Answer 19

simple columnar (PCT)
squamos (thin descending)
cuboidal (thick ascending limb)

Question 20

what is the juxtaglomerular apparatus

Answer 20

specialisation of afferent arteriole and DCT

Question 21

what lines the DCT?

Answer 21

macula densa

Question 22

where are juxtaglomerular cells located

Answer 22

adjacent to afferent arteriole

Question 23

where is the macula densa

Answer 23

adjacent to the JMA lining the DCT

Question 24

how does epithelium change from collecting tubule - CD

Answer 24

cuboidal to columnar

Question 25

what cells are found in collecting tubules

Answer 25

principle cells

intercalated cells

Question 26

what is the epithelium in ureter

Answer 26

transitional

Question 27

describe the structure of ureter

Answer 27

2 layers of smooth muscle, outer circular inner longitudinal

Question 28

what epithelium in bladder

Answer 28

transitional

Question 29

describe layers of bladder

Answer 29

1. epithelium (highly folded to allow stretch)
2. inner longitudinal
3. outer circular
4. outermost longitudinal

Question 30

what do renal veins drain into

Answer 30

inferior vena cava

Question 31

what drives filtration at glomerulus

Answer 31

starling forces

Question 32

what are starling forces?

Answer 32

pressure differences between hydrostatic (out of capillaries) and oncotic pressure

Question 33

the juxtaglomerular complex consists of what cells

Answer 33

1. juxtaglomerular cells
2. macula densa
3. mesangial cells
4. lacis cells

Question 34

function of juxtaglomerular cells

Answer 34

secretere renin - renin angiotensin system

Question 35

function of macula densa cells

Answer 35

reabsorb Na

Question 36

function of lacis cells

Answer 36

store and secrete erythropoietin

Question 37

what are mesangial cells and what is their function

Answer 37

specialised smooth muscle cells that can contract to reduce GFR (glomerular filtration rate)

Question 38

function of principle cells (DCT)

Answer 38

reabsorb Na

secrete k+

Question 39

function of intercalated A cells (DCT)

Answer 39

reabsorb K+
reabsorb HCO3-
secrete H+

Question 40

function of intercalated B cells

Answer 40

secrete HCO3- in response to alkalosis