Practical - histology

Question 1

What are the 2 poles in the glomerular apparatus?

Answer 1

Vascular pole - with afferent arteriole in and efferent arteriole out

Urinary pole - filtrate drains into PCT

Basically the side of the glomerulus

Question 2

What type of epithelium lines the Bowman’s capsule and why does it not need tight junctions?

Answer 2

Simple squamous and no special tight junctions are required as the primary urine is isotonic (same osmolarity as blood).

Question 3

Does it appear that there are more PCT or DCT and why?

Answer 3

There are equal numbers of DCT and PCT, however there apppears to be more PCTs in histology
- This is because they are longer and more convoluted so you cut the same one more than once leading to an apparent greater abundance

Question 4

Compare the PCT with the DCT

Answer 4

• PCT has microvilli and they traps a layer of GAGs and so it appears in slides to have a ‘musty film’ of mucus which is distinct from the DCT lumen
• PCT also has: thicker walls, more cytoplasm and less prominent nuclei, more mitochondria

Question 5

What are some special features of the urothelium?

Answer 5

• 3-5 cells thick in a stratified appearance.
• Ability to stretch to accommodate volumes of urine.
• Covered in a gel coating of GAGs to protect it from urine

Question 6

How are the muscles arranges in the ureter?

Answer 6

Has a layer of VSMCs in a circular muscle layer and a longitudinal muscle layer that control peristalsis.

Question 7

Describe the arrangement of the detrussor muscle

Answer 7

• Consists of 3 obliquely organised layers of muscle.
• These muscle layers allow the bladder wall to contract in all directions to effectively expel urine.
• 2x longitudinal muscle layers, 1x circular layer
• Arranged longitudinal, circular, longitudinal