renal histology Flashcards Preview

GU > renal histology > Flashcards

Flashcards in renal histology Deck (16):
1

what are the functions of the kidney

- filter blood to remove waste as urine
- regulate water, salt, acid-base balance
- regulate BP
- produce hormones/enzymes (e.g. renin)

2

describe a nephron

- is the smallest functional unit of the kidneys
- it is a filtering tubule
- there are around 1 million per kidney
- blood filter attached to a tubular epithelium

3

what cells line the renal corpuscle

podocytes (envolope capillaries)
parietal epithelial cells (squamous)

4

what are the 3 main components of the glomerular filtration barrier

- endothelium (wall of capillary)
- glomerular basement membrane
- podocytes

5

function of the glomerular filtration barrier

-physical barrier
- charged selective barrier (repels negative charges)
e.g. albumin
- restricts large proteins

6

describe the glomerular capillary endothelium

- negatively charged glycocalyx (repels negatively charged proteins)
- holes which are permeable to small molecules

7

describe the glomerular basement membrane

-thick
- made up of collagen and negatively charged proteoglycans
- has a dense core and less dense outer layer
- acts as a physical (inner) and charged barrier (outer)

8

describe the podocytes

- adhere to GBM
- forms slits through primary and secondary processes
- covered in a negatively charged glycocalyx coat

9

define podocyte effacement

a disease damaging the glomerular filter - causing a leaky filter

10

describe the role of mesangial cells

- SM cells packed inside capillary tuft
- maintain tuft shape
- produce ECM
- loss of function results in glomerular scarring from overproducing ECM

11

describe the contents of the juxtaglomerular apparatus

JG cells - modified SM cells that line the afferent arteriole and can secrete renin
macula densa cells - special cells lining thick ascending limb, sense salt conc in filtrate (flow rate)
extraglomerular mesangial cells

12

describe the function of the juxtaglomerular apparatus

- if the concentration of salt in the distal tubule is high it will induce afferent arteriolar vasoconstriction
- if the flow/salt concentration is low then it will induce renin release

13

features of proximal tubule cells

- cuboidal epithelium
- brush border (microvilli) to increase surface area
- pinocytosis
- lateral processes and infoldings to increase surface area

14

features of thin limb cells

- thin squamous epithelium
- role in water reabsorption as part of LOH
- nuclei bulge into lumen

15

features of distal tubule cells

- no brush border
- no pinocytosis
- cuboidal
- lateral processes and infoldings

16

features of collecting duct cells

-cuboidal to columnar epithelium