Urinary1 - Anatomy of the Urinary System

Question 1

What is the relative position of the kidneys and the ureters?

Higher Pole
Lower Pole
Hilum and Ureter

Answer 1

1. ) left is higher than the right and reaches the 11-12th rib
   - right kidney reaches the 12th rib
2. ) lower poles of the kidney occur around the L3-L4 intervertebral disc
3. ) the hilum and beginning of the ureter are at L1 vertebral level

Question 2

4 features of the renal facial layers and fat

Answer 2

1. ) anterior and posterior renal fascia
2. ) Pararenal (paranephric) Fat - extraperitoneal and external to the posterior renal fascia
3. ) Perirenal (perinephric) Fat - surrounds the kidney within the renal fascial layers
   - continuous with the fat in the renal sinus of the kidney
4. ) collagen bundles from the fascia help to keep the renal fat and the kidneys in place

Question 3

4 features of the ureter

Ureteric Wall
Descension
Divisions
Route

Answer 3

1. ) Ureteric Wall - lumen is coated with urothelium which contains smooth muscles fibres to propel urine to the bladder (peristaltic waves)
2. ) Descension - descends anterolaterally to the tips of the transverse processes of the lumbar vertebrae
3. ) Divisions - divided into the abdominal (proximal), pelvic, and intramural segments
4. ) Route - runs under the vas deferens and superior to seminal vesicles in men and runs behind the ovary and uterine artery in women

Question 4

4 features of the ureter in the intramural segment

Answer 4

1. ) Intramural segment is where the ureter passes through the bladder
2. ) it coalesces with bundles of the detrusor muscle in the bladder wall
3. ) length of intramural part is 1.2-2.5cm
4. ) there is no sphincter at the vesicular urethral junction (VUJ)
   - bladder muscles forms a flap to stop urine from moving back up the ureter

Question 5

What are the 5 arteries in the kidneys

Answer 5

1. ) Renal - divides into anterior and posterior branches
2. ) 5 Segmental - apical, upper, middle, lower, posterior
3. ) Interlobar - between the pyramids
4. ) Arcuate - between the cortex and medulla
5. ) Interlobular - penetrates through the cortex

Question 6

What is the complete path of blood supply to the kidneys

Answer 6

Aorta –> renal artery –> segmental artery –> interlobar artery –> arcuate artery –> interlobular artery –>

afferent arteriole –> glomerulus –> efferent arteriole –> peritubular capillaries or vasa recta

interlobular vein –> arcuate vein –> interlobar vein –> segmental vein –> renal vein –> Inferior Vena Cava

Question 7

5 differences between the cortical and juxtamedullary nephron

Size
Efferent Arteriole
Innervation
Renin
Distribution

Answer 7

1. ) Size - juxtamedullary has a bigger glomerulus and longer loop of Henle
2. ) Efferent Arteriole - cortical goes to form peritubular capillary whilst juxta forms the vasa recta
3. ) Innervation - cortical has a rich sympathetic innervation whilst juxta.. has poor innervation
4. ) Renin - high conc of renin in cortical and almost none in the juxta
5. ) Distribution - cortical makes up 90% of the nephrons

Question 8

What is the size and weight of a normal kidney?

What can the size of the kidneys tell you?

Answer 8

• Normal kidney is 9-14 cm long, 6-7 cm wide
• Weighs approx 200g
• Males have larger kidneys
• If discrepancy in size between the left and right is >2cm, suggests pathology
• Small kidneys could suggest chronic kidney disease

Question 9

Describe the microscopic appearance of a kidney

Answer 9

Ureter –> Renal Pelvis –> Hilus –> Major Calyx –> Minor Calyx –> Renal Papilla –> Renal Pyramid (Medulla)
Cortex with renal columns in between the renal pyramids
Renal Lobe = medulla + cortex above
Renal Capsule has an outer layer and an inner layer
Renal Sinus - cavity containing adipose tissue

Question 10

4 features of the bladder

Answer 10

1. ) Detrusor Muscle - smooth muscle in bladder wall that remains relaxed to allow storage of urine. It contracts to release urine
2. ) Trigone - triangular region formed by 2 ureteric orifices and the internal urethral sphincter (IUS), there is no detrusor muscle
3. ) Rugae - mucosa is folded except in the trigone
4. ) Palpation - can be palpated when full because they expand above the level of the pubic symphysis

Question 11

3 features of the urethral divisions in males and females

IUS
EUS
Male Divisions x4

Answer 11

1. ) IUS - IUS in males contracts under sympathetic stimulation to prevent retrograde ejaculation
2. ) EUS is used for continence in males and females and is always found in the urogenital diaphragm (pelvic floor)
3. ) Males - prostatic urethra –> membranous urethra –> bulbous urethra –> spongy (penile) urethra)

Question 12

What are the 3 common sites where renal stones can lodge due to non uniformity in lumen diameter if the ureter

Answer 12

VUJ - vesicoureteric junction
PUJ - pelviureteric junction
Pelvic brim