Histology Of Urinary System

Question 1

What are the 4 principal components urinary tract

Answer 1

Kidneys
Ureters
Bladder
Urethra

Question 2

What are the 3 prime layers of the kidneys

Answer 2

Outer cortex - pale
Underlying medulla - darker
Central renal pelvis

Question 3

What are medullary rays and where are they found

Answer 3

Collection of loops of henle and collecting ducts that originate from the nephrons that have their renal corpuscles in the outer part of the cortex

Renal cortex

Question 4

What does the renal medulla comprise of

Answer 4

Loops of henle and collecting ducts of nephrons both close to and far from the capsular surface of the kidneys

Question 5

What is the glomerulus

Answer 5

Tuft of convoluted fenestrated capillaries resting on a glomerular basement membrane

Question 6

Give the names of the structures that a) line b) support and c) encase the glomerulus

Answer 6

a) podocytes
b) mesangial cells - lie between capillary loops
c) bowmans capsule

Question 7

How can you distinguish between capillary endothelial cells and mesangial cells histologically

Answer 7

Capillary endothelial cells nuclei lie on the inside of capillaries
Mesangial cells lie between capillaries

Question 8

What are the 2 components of the juxtaglomerular apparatus

Answer 8

Afferent arteriole

Distal convoluted tubule

Question 9

How are granule cells formed and whats their function

Answer 9

Endothelium of afferent arteriole expands to form mass of cells - granular cells
These secrete renin in response to low blood pressure

Question 10

Whats the role of macula densa

Answer 10

Specialised part of the distal convoluted tubule that senses [NaCl] and regulates tubuloglomerular feedback

Question 11

Where are macula densa found

Answer 11

Closely packed endothelial cells along the distal convoluted tubule

Question 12

How are proximal convoluted tubule recognised histologically

Answer 12

Simple cuboidal epithelium
Round central/ basal nuclei
Brush border of microvilli at apical end
Many mitochondria - appears eosinohpillic

Question 13

Function of proximal convoluted tubule

Answer 13

Reabsoprtion of NaCl, proteins, polypeptides, amino acids, glucose

Question 14

What type of epithelium lines thick and thin segments of the loop of henle

Answer 14

Thick - low cuboidal

Thin - simple squamos

Question 15

What supplies the loop of henle

Answer 15

Rich vasa recta

Question 16

How are distal convoluted tubules seen histologically

Answer 16

Low cuboidal epithelium
Scanty microvilli
Numerous mitochondria

Question 17

Function of the distal convoluted tubule

Answer 17

Regulates acid base by secreting H+ and absorbing HCO3-

Regulates Na level by exchanging Na for K

Question 18

What type of epithelium lines the collecting duct

Answer 18

Cuboidal epithelium

Question 19

Function of the collecting duct

Answer 19

Water reabsorption
Na balance
Acid- base balance

Question 20

What 2 cells are the collecting duct made up of and whats their function

Answer 20

Prinicipal cells - respond to aldosterone and ADH

Intercalated cells - exchange H+ for HCO3-

Question 21

Desribe the appearance of the nuclei in the collecting duct

Answer 21

Round and central

Question 22

What epithelium lines the renal pelvis and describe this type

Answer 22

Urothelium - multilayered stratified epithelium

Layer of umbrella cells overlying a pseudostratified columnar layer of polygonal cells

Question 23

Whats the function of the renal pelvis

Answer 23

Transmits filtrate from nephron to ureter

Question 24

What epithelium lines the ureter

Answer 24

Transitional epithelium - urothelium

Question 25

What is the ureter and give its function

Answer 25

Spiral Muscular tubes that convey urine via peristalsis from the kidney to the bladder

Question 26

Desribe the structure of ureters

Answer 26

Inner longitudinal layer Outer circular layer No serosa Loose adventitia

Question 27

Give the layers of the bladder

Answer 27

``` Urothelium Lamina propria Muscularis mucosa Submucosa Muscularis propria Subserosa and serosa ```

Question 28

What does the functional valve of the bladder do

Answer 28

Prevent reflux into ureter

Question 29

How does epithelium change proximally vs distally in a female urethra

Answer 29

Prox - urothelium | Dist - non keratinising stratified squamous

Question 30

What 2 glands open into the female urethra

Answer 30

Paraurethral and periurethral

Question 31

How length differ in the fem vs male urethra

Answer 31

Fem 4-5cm | Male 20cm

Question 32

What are the 3 parts of the male urethra

Answer 32

Prostatic urethra Membranous urethra lined by urothelium Penile urethra

Question 33

How does the epithelium of the penile urethra differ proximally vs distally

Answer 33

Proximally - pseudostratified | Distally - stratified squamous

Question 34

What structures does the cortex of the kidneys contain

Answer 34

Glomeruli Convoluted (coiled) parts of the proximal and distal tubules Proximal parts of the collecting ducts

Question 35

What structures does the medullary pyramids contain

Answer 35

Straight portions of the proximal and distal tubules Loops of henle Distal parts of collecting duct

Question 36

Where does filtrate that drains from each medullary pyramid drain into

Answer 36

Funnel shaped calyx

Question 37

Where do the renal artery and vein enter and leave the kidney

Answer 37

Hilum

Question 38

Describe the branching of the renal artery and where this occurs

Answer 38

Renal artery usually divides into 5/6 branches that give off arcuate arteries at the cortico-medullary junction Interlobular arteries arise from these

Question 39

What divides the cortex inter lobules

Answer 39

Interlobular arteries penetrate the cortex at regular intervals

Question 40

What supplies the glomeruli

Answer 40

Afferent arterioles given off from interlobular arteries | This is where blood is filtered

Question 41

How does filtered blood leave the glomeruli and describe its return to systemic circulation

Answer 41

Leaves via Efferent arterioles and passes through thin walled vessels between the tubules Here it gains fluid and ions recovered by the nephrons before draining into arcuate veins for return to systemic circulation

Question 42

What gives off straight arterioles and where

Answer 42

Arcuate arteries | Near cortico-medullary junction

Question 43

Straight arterioles penetrate deep into the …….. before returning blood to the ……… ……..

Answer 43

Medulla | Arcuate veins

Question 44

Which structures are found most prevalent in the renal cortex

Answer 44

Proximal convoluted tubules