Session 2 - Function Histology of UT and Embryology Flashcards
GIve the order of tubules in the nephron.
Glomerulus -> PCT -> Loop of Henle -> DCT -> Collecting Duct
What are podocytes?
Podocytes are cells that have long projections that wrap around the capillaries in the glomerulus to form filtration slits
What features of the capillaries in the glomerulus help them to form a filter?
The endothelium is fenestrated meaning that plasma can leak out
What epithelium is present in the PCT?
Simple Cuboidal epithelium
What are the four parts of the Loop of Henle?
- Pars Recta
- Thin Descending Limb
- Thin Ascending Limb
- Thick Ascending Limb
What epithelium lines the thin limbs of the Loop of Henle?
Simple Squamous
How can you differentiate the thin limbs of the Loop of Henle from a capillary?
There are no RBCs in the thin limbs
What epithelium lines the thick ascending limb?
Simple Cuboidal
How can you differentiate the thick ascending limb from the PCT?
No brush border on the epithelium in the Thick ascending limb
What three parts make up the Juxtaglomerular Apparatus?
- Macula Densa
- Juxtaglomerular cells
- Extraglomerular mesangial cells
What two characteristics can we use of the collecting duct to differentiate it from the DCT?
- Lumen is larger
- Lumen is more irregular than circular
What epithelium lines the ureter?
Specialised transitional epithelium
What type of specialised cells make the bladder wall impermeable?
Umbrella Cells
Name the three embryonic kidney structures.
Pronephros, mesonephros and metanephros
What is important about the mesonephric duct?
It sprouts the ureteric bud, the primordium of collecting system in the post-Utero kidney
What is important about the mesonephric duct in males only?
It has an important role in the development of the reproductive tract
Why is the term the ‘ascent’ of the kidneys not truly correct?
Because embryonic growth is cranial to caudal, the caudal end now grows significantly more causing the trunk to grow downwards
What is renal agenesis? And how may it occur?
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
Why may a ‘horseshoe’ kidney form?
During the ‘ascent’ of the kidneys they lie very close to each other and may fuse
How may splitting of the ureteric bud cause incontinence?
It may have an ectopic opening that bypasses the bladder and hence the patient can no longer control when they pass urine
Why are abnormal renal vessels relatively common?
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
From which part of the primitive gut does the bladder grow?
Hindgut
What is the cloaca divided by and into?
The urorectal septum divides the cloaca into the urogenital sinus and the urorectal canal
What is the adult remanant of the urachus?
Median umbilical ligament
In what way is the development of the male and female bladder different?
The mesonephric ducts regress in females due to the lack of male hormones. In males the mesonephric duct forms parts of the reproductive tract
What are the four parts of the male urethra?
- Pre-prostatic
- Prostatic
- Membranous
- Spongy
Describe Hypospadias.
- defect in the fusion of the urethral folds
- urethra opens onto ventral surface rather than end of glans
- incidence is increasing
