Session 2 - Function Histology of UT and Embryology

Question 1

GIve the order of tubules in the nephron.

Answer 1

Glomerulus -> PCT -> Loop of Henle -> DCT -> Collecting Duct

Question 2

What are podocytes?

Answer 2

Podocytes are cells that have long projections that wrap around the capillaries in the glomerulus to form filtration slits

Question 3

What features of the capillaries in the glomerulus help them to form a filter?

Answer 3

The endothelium is fenestrated meaning that plasma can leak out

Question 4

What epithelium is present in the PCT?

Answer 4

Simple Cuboidal epithelium

Question 5

What are the four parts of the Loop of Henle?

Answer 5

• Pars Recta
• Thin Descending Limb
• Thin Ascending Limb
• Thick Ascending Limb

Question 6

What epithelium lines the thin limbs of the Loop of Henle?

Answer 6

Simple Squamous

Question 7

How can you differentiate the thin limbs of the Loop of Henle from a capillary?

Answer 7

There are no RBCs in the thin limbs

Question 8

What epithelium lines the thick ascending limb?

Answer 8

Simple Cuboidal

Question 9

How can you differentiate the thick ascending limb from the PCT?

Answer 9

No brush border on the epithelium in the Thick ascending limb

Question 10

What three parts make up the Juxtaglomerular Apparatus?

Answer 10

• Macula Densa
• Juxtaglomerular cells
• Extraglomerular mesangial cells

Question 11

What two characteristics can we use of the collecting duct to differentiate it from the DCT?

Answer 11

• Lumen is larger

- Lumen is more irregular than circular

Question 12

What epithelium lines the ureter?

Answer 12

Specialised transitional epithelium

Question 13

What type of specialised cells make the bladder wall impermeable?

Answer 13

Umbrella Cells

Question 14

Name the three embryonic kidney structures.

Answer 14

Pronephros, mesonephros and metanephros

Question 15

What is important about the mesonephric duct?

Answer 15

It sprouts the ureteric bud, the primordium of collecting system in the post-Utero kidney

Question 16

What is important about the mesonephric duct in males only?

Answer 16

It has an important role in the development of the reproductive tract

Question 17

Why is the term the ‘ascent’ of the kidneys not truly correct?

Answer 17

Because embryonic growth is cranial to caudal, the caudal end now grows significantly more causing the trunk to grow downwards

Question 18

What is renal agenesis? And how may it occur?

Answer 18

Kidney fails to develop

If the ureteric bud fails to interact with the he intermediate mesoderm, one or both of the kidneys may not develop

Question 19

Why may a ‘horseshoe’ kidney form?

Answer 19

During the ‘ascent’ of the kidneys they lie very close to each other and may fuse

Question 20

How may splitting of the ureteric bud cause incontinence?

Answer 20

It may have an ectopic opening that bypasses the bladder and hence the patient can no longer control when they pass urine

Question 21

Why are abnormal renal vessels relatively common?

Answer 21

As the kidney ‘ascends’ there blood supply changes and old vessels retract and new ones now supply the kidneys.
If the old ones do not retract then the kidney will have abnormal renal vessels

Question 22

From which part of the primitive gut does the bladder grow?

Answer 22

Hindgut

Question 23

What is the cloaca divided by and into?

Answer 23

The urorectal septum divides the cloaca into the urogenital sinus and the urorectal canal

Question 24

What is the adult remanant of the urachus?

Answer 24

Median umbilical ligament

Question 25

In what way is the development of the male and female bladder different?

Answer 25

The mesonephric ducts regress in females due to the lack of male hormones. In males the mesonephric duct forms parts of the reproductive tract

Question 26

What are the four parts of the male urethra?

Answer 26

• Pre-prostatic
• Prostatic
• Membranous
• Spongy

Question 27

Describe Hypospadias.

Answer 27

• defect in the fusion of the urethral folds
• urethra opens onto ventral surface rather than end of glans
• incidence is increasing