LUT Pathology

Question 1

components of the LUT

Answer 1

bladder - stores urine
urethra - controls bladder emptying

Question 2

LUT histological layers

Answer 2

mucosa
muscularis
adventitia/serosa

Question 3

LUT mucosa

Answer 3

transitional epithelium + lamina propria

Question 4

transitional epithelium

Answer 4

non-keratinized, stratified epithelium lining the renal pelvis, ureters, bladder, and urethra

distensible - stretches while remaining impermeable

variable cell layers depending on stretch/relaxation

Question 5

is muscularis layer smooth or skeletal muscle

Answer 5

smooth muscle (detrusor muscle)

Question 6

LUT muscularis

Answer 6

inner longitudinal
outer circular
outer longitudinal (only in bladder)

Question 7

LUT adventitia vs serosa

Answer 7

fibrous connective tissue

adventitia: surrounds retroperitoneal structures

serosa: surrounds peritoneal structures

Question 8

LUT developmental disorders

Answer 8

• duplicated ureters
• ectopic ureters
• patent urachus
• urethrorectal/rectovaginal fistula

Question 9

duplicated ureters

Answer 9

ureters from the cranial and caudal pole of the kidney do not fuse into one

causes two ureters to exit a single kidney

cranial ureter often ectopic

Question 10

ectopic ureters

Answer 10

congenital abnormality where the ureter doesn’t terminate at the trigone of the bladder

can be intra or extramural

ID’d in young (3-6 months) animals

clinical sign: urinary incontinence

Question 11

intramural ectopic ureter

Answer 11

ureter enters at the trigone but tunnels through the bladder wall and terminates in the urethra

Question 12

extramural ectopic ureter

Answer 12

ureter bypasses the trigone entirely and terminates directly into the urethra

Question 13

patent urachus

Answer 13

urachus (the tube between the bladder and umbilicus during fetal development) does not close after birth, creating a channel between the bladder apex and the umbilicus

urine drains out of umbilicus

predisposes to infection and rupture (uroperitoneum)

partial closure –> urachal cysts w/ metaplasia

Question 14

urethroectal/rectovaginal fistula

Answer 14

abnormal connection between the urethra and rectum or rectum and vagina causing urination from the rectum

Question 15

urolithiasis

Answer 15

solid formations composed of organic and mineral matrix (calculi, stones, uroliths) along the urinary tract

Question 16

risk factors for uroliths

Answer 16

diet
mineral accumulations in forage
infection
breeds
urine pH
water intake
anatomic barriers

Question 17

what can urolithiasis and hydronephrosis predispose an animal to

Answer 17

pyelonephritis

Question 18

urethral obstruction

Answer 18

blockage in the urethra

Question 19

are urethral obstructions more common in males or females

Answer 19

males - longer urethra

Question 20

what can urethral obstructions/uroliths cause

Answer 20

• pressure necrosis leading to ischemia
• ulceration of the mucosa
• cystitis and pyelonephritis (due to urinary stasis)
• hydronephrosis + hydroureter

Question 21

vermiform appendage

Answer 21

narrowing of the distal urethra in small ruminants

frequent site of obstructions in goats

Question 22

what are most common sites of obstruction in goats

Answer 22

vermiform appendage
sigmoid flexures

Question 23

nephroliths

Answer 23

kidney stones

Question 24

cystoliths

Answer 24

bladder stones

Question 25

what are some consequences of UT obstruction

Answer 25

- severe cystitis (necrotic, hemorrhagic, inflammation, ulceration) - ruptured bladder - uroabdomen - hydronephrosis (can be caused by any obstruction, not just uroliths) - progressive renal atrophy

Question 26

types of LUT inflammation

Answer 26

ureteritis cystitis

Question 27

ureteritis

Answer 27

inflammation of the ureters (rare w/o concurrent cystitis) caused by calculi in bladder

Question 28

cystitis

Answer 28

inflammation of the bladder (main site of LUT inflammation) causes: bacterial, fungal, viral, drugs

Question 29

does cystitis occur more in males or females

Answer 29

females due to shorter urethra

Question 30

what type of cells predominate in acute cystitis

Answer 30

neutrophils

Question 31

what type of cells predominate in chronic cystitis

Answer 31

mononuclear cells

Question 32

follicular cystitis

Answer 32

proliferation of lymphoid tissue

Question 33

polypoid cystitis

Answer 33

overgrowth/folds of mucosa into bladder lumen

Question 34

emphysematous cystitis

Answer 34

gas filled inflammation of the bladder caused by gas production by glucose-consuming bacteria occurs with diabetes mellitus (causes glucosuria)

Question 35

bladder defense against infection

Answer 35

micturition hydro kinetic washout peristalsis in ureters urine pH glycosaminoglycan coating urothelial cell shedding immunoglobulins

Question 36

what is the most common LUT neoplasia

Answer 36

transitional cell carcinoma (epithelial)

Question 37

transitional cell carcinoma

Answer 37

urothelial cell carcinoma; proliferation of the transitional cell layer can be infiltrative or non-infiltrative

Question 38

bracken fern toxicosis mechanism

Answer 38

bracken fern contains ptaquiloside toxin chronic consumption of bracken fern --> hemorrhagic cystitis --> persistent hematuria, anemia, UT neoplasia

Question 39

ptaquiloside

Answer 39

glycoside toxin myelodysplastic and carcinogenic

Question 40

what species does bracken fern toxicosis occur in

Answer 40

cattle some sheep

Question 41

what type of calculus gives sabulous cystitis its sand-like texture

Answer 41

Calcium carbonate in horses

Question 42

most common site of LUT obstruction in cats

Answer 42

within penis

Question 43

most common site of LUT obstruction in cattle

Answer 43

sigmoid flexure ischial arch

Question 44

most common site of LUT obstruction in dogs

Answer 44

proximal os penis

Question 45

most common site of LUT obstruction in horses

Answer 45

kidney urinary bladder (sand-like cystitis)

Question 46

most common site of LUT obstruction in pigs

Answer 46

kidney

Question 47

most common site of LUT obstruction in sheep/goats

Answer 47

urethral process (vermiform appendage) sigmoid flexure

Question 48

what type of epithelium lines the LUT

Answer 48

transitional epithelium

Question 49

urine dribbling from the umbilical remnant of a neonate likely has what developmental abnormality

Answer 49

patent urachus

Question 50

a neonate with urinary incontinence is likely to have what developmental abnormality

Answer 50

ectopic ureter

Question 51

where should the ureter enter the bladder

Answer 51

trigone

Question 52

LUT defense mechanisms

Answer 52

micturition hydro kinetic washout peristalsis in ureters urine pH shedding urothelial cells

Question 53

LUT risk factors

Answer 53

glycosuria corticosteroid administration obstruction catheterization

Question 54

what lesions can cause hydronephrosis

Answer 54

urolithiasis prostatic carcinoma ureter ligation during spay trigonitis urethral stricture all cause obstruction of the urethra --> hydronephrosis

Question 55

acute cystitis gross appearance

Answer 55

hemorrhagic, swollen

Question 56

follicular cystitis gross appearance

Answer 56

small, diffuse nodules histology: dark blue lymph aggregate

Question 57

polypoid cystitis

Answer 57

white/suppurative discharge histology: folds of mucosa into the lumen

Question 58

what renal function controls the amount of urea entering the proximal tubule

Answer 58

glomerular filtration rate

Question 59

what stain is used to detect amyloid

Answer 59

congo red

Question 60

what does basement membrane thickening cause

Answer 60

proteinuria