Histology of urinary tract

Question 1

structure of the renal cortex

Answer 1

dark brown and granular

Question 2

renal medulla contains

Answer 2

renal pyramids

Question 3

fibrous capsule made of

Answer 3

collagen, smooth muscle and elastic fibres

Question 4

divisions of the renal pelvis

Answer 4

2 or 3 major calyces which divide into minor calyces

Question 5

flow of urine

Answer 5

pyramids to calyces to renal pelvis and then into the ureter

Question 6

process of kidney

Answer 6

filtration
active absorption
passive absorption
secretion
excretion

Question 7

functional unit fo the kidney

Answer 7

uriniferous tubule

highly convoluted, made of the nephron and collecting duct

Question 8

structure of uriniferous tubules

Answer 8

epithelial
separated from connective tissue by basal lamina
most connective tissue is highly vascularised

Question 9

first part of the nephron

Answer 9

renal corpuscle

Question 10

components of renal corpuscle

Answer 10

bowmans capsule = dilated pouch at the proximal end of nephron
glomerulus = tuft of capillaries invaginated into capsule

Question 11

two poles of the renal corpuscle

Answer 11

vascular pole and urinary pole

arterioles enter and leave at the vascular

Question 12

vascular supply to glomerulus

Answer 12

supplied by afferent
drained by efferent
composed of anastamosing fenestrated capillaries

Question 13

function of urinary pole

Answer 13

where the PCT leaves

with fluid

Question 14

what is the function of the renal corpuscle

Answer 14

blood filtering

Question 15

layers of the renal corpuscle

Answer 15

parietal (external) is simple squamous
visceral (internal) envelopes capillaries, has podocytes
bowmans space is between layers

Question 16

specialised cells within connective tissue

Answer 16

mesangial cells
specialised smooth muscle cells
regulate blood flow through capillaries

Question 17

extraglomerular mesangial cell function

Answer 17

on vascular pole, relay information

Question 18

intraglomerular mesangial cell function

Answer 18

are pericytes which are phagocytic, respond to vasoactive hormones and contract narrow capillaries
synthesise NO

Question 19

how does filtration occur

Answer 19

difference in diameters of arterioles creates a hydrostatic pressure gradient

Question 20

layers of filtration apparatus

Answer 20

fenestrated capillaries, basal lamina, podocyte split pors

Question 21

fenestrated capillary layer

Answer 21

barrier to macromolecules
endothelial cells are attenuated
pores large

Question 22

basal lamina structure

Answer 22

3 layers
lamina rara interna
lamina densa
lamina rara externa

Question 23

basal lamina function

Answer 23

collagen in basal lamina separates by size
heparin sulphate separated bu charge
larger molecules and negatively charged molecules are blocked
fluid which contains small molecules and ions pass through

Question 24

podocytes structure

Answer 24

adjacent podocytes interdigitate to cover basal lamina
primary processes = have numerous long cytoplasmic extensions
secondary processes = pedicels which completely envelope most of capillaries

Question 25

podocyte fucntion

Answer 25

between processes are filtration slits, covered by a thin slit diaphragm act as a filtration barrier to shape and size

Question 26

3 parts of reabsorption system and subsequent divisions

Answer 26

PCT: pars convuluta and pars recta Loop: descending thin, hairpin, ascending thin DCT: ascending thick loop, macula densa, pars convuluta

Question 27

tissue type of PCT

Answer 27

cuboidal epithelium, very leaky

Question 28

tissue tube of loop

Answer 28

squamous epithelium, contains aquaporins

Question 29

tissue type of DCT

Answer 29

cuboidal cells, in macula densa are tall and thin

Question 30

adaptations of cells in PCT

Answer 30

- microvilli and canaliculi that increase SA for reabsorption - heights of cells vary with functional state - epithelium has eosinophilic granular cytoplasm - lots of mt for ion transport - lots of lysosomes for endocytosis and breakdown of small proteins

Question 31

function of thin descending limb

Answer 31

water reabsorption | have aquaporins and simple squamous

Question 32

thin ascending limb function

Answer 32

absorption of ions, not water

Question 33

reabsorption from the loop of Henle

Answer 33

reabsorbed by the vasa recta continuous endothelial in descending vessels fenestrated endothelial cells in ascending vessels

Question 34

3 parts of DCT

Answer 34

pars recta = thick ascending limb macula densa pars convoluta

Question 35

function of DCT

Answer 35

ion exchange and maintaining acid-base balance

Question 36

cells in DCT

Answer 36

shorter cuboidal no bruh border elaborate basal membrane invaginations for ion transport

Question 37

thick ascending limb cell type

Answer 37

simple cuboidal

Question 38

where is the DCT the macula densa

Answer 38

where it has established contact with the vascular pole of the parent nephron

Question 39

location of the juxtaglomerular apparatus

Answer 39

between the vascular pole and the DCT

Question 40

JGA made of

Answer 40

macula densa of DCT extraglomerular cells juxtaglomerular cells

Question 41

function of macula densa cells

Answer 41

cells sensitive to ionic content and water volume of fluid in DCT, release prostaglandins

Question 42

function of extraglomerular cells

Answer 42

relay info from MD to juxtaglomerular cells

Question 43

function of juxtaglomerular cells

Answer 43

found at afferent glomerular arteriole, smooth muscle cells, produce renin when MD detects fall in ions in DCT

Question 44

overall functions of JGA

Answer 44

regulate BP regulate renal blood flow regulate GFR

Question 45

cortical region of collecting duct

Answer 45

in medullary rays made of principle cells, with single cilium, controlled by aldosterone also intercalated cells, involved in acid base balance

Question 46

medullary region of collecting duct

Answer 46

controls reabsorption of water and urea, controlled by ADH

Question 47

collecting duct cell type

Answer 47

simple cuboidal | impermeable ton water except with ADH

Question 48

ureter features

Answer 48

lined by mucosa, has muscular coat and a covering of fibrous connective tissue made of transitional epithelium muscular contraction of wall conveys urine to the bladder

Question 49

plaques in plasma membrane of transitional epithelium

Answer 49

plasma membrane has thickened plague regions and inter-plaque regions plaques contain glycoproteins to protect cells reserve plasma membrane stored in vesicles for when the bladder is stretched plowers folded into empty bladder and so disappear when stretched

Question 50

features of detrusor muscle

Answer 50

subepithelial connective tissue | three smooth muscle layers