US Lecture 1 - The Kidney and Urinary Tract

Question 1

What does the kidney and urinary tract comprise?

Answer 1

Kidneys, ureters, urinary bladder and urethra

Question 2

Where are the kidneys located?

Answer 2

In upper abdomen - RETROPERITONEAL, surrounded by dense fibrous capsule, which has renal fascia containing the peri-renal adipose tissue

Question 3

What overlaps the kidneys?

Answer 3

The diaphragm posteriorly and the pleural cavity superiorly

Question 4

What is the difference between the location of the right and the left kidney?

Answer 4

Right kidney is slightly lower than the left - superior pole of RK lies at 11th intercostal space and LK at 11th rib

Question 5

Where are the hilums of the kidneys located?

Answer 5

Around L1

Question 6

Fill in the blanks of the urinary system

Answer 6

Question 7

What are the anterior relations of the kidney?

Answer 7

Right: liver, hepatic flexure and hilus lies behind 2nd part of duodenum Left: stomach, pancreas, spleen and splenic flexure

Question 8

How are the kidneys supplied with blood?

Answer 8

Via renal arteries (short direct branches from abdominal aorta), BP drives ultrafiltration Renal vein drains into IVC

Question 9

What does the abdomen vasculature look like in relation to the kidneys? - Fill in the blanks

Answer 9

Question 10

What is the basic structure of the kidney? - FITB

Answer 10

Question 11

Why does the cortex look granular?

Answer 11

Due to random organisation

Question 12

Why is the medulla of the kidney striated?

Answer 12

Due to radial arrangement of tubules and micro-vessels

Question 13

What is the kidney split into and why is that important?

Answer 13

It is multilobar, so each lobe drains through its own papilla and calyx

Question 14

What does the structure of the inside of the kidney look like? FITB

Answer 14

Question 15

Where are the ureters located?

Answer 15

Run vertically down posterior abdominal wall in the plane of the tips of the transverse processes of the lumbar vertebrae Crosses pelvic brim anterior to sacro-iliac joint and bifurcation of common iliac arteries

Question 16

How do the ureters descend down the abdominal cavity?

Answer 16

Anteromedially to enter bladder at the level of ischial spine - need to go around the rectum (and vagina in females) to reach the bladder

Question 17

How does urine travel down the ureter?

Answer 17

By peristalsis in the smooth muscle walls of the ureters - open diagonally through bladder wall

Question 18

What are the 3 sites of ureteric constriction?

Answer 18

Pelviureteric junction, where ureter crosses pelvic brim and where ureter traverses bladder wall

Question 19

Why does renal colic occur and where are they most likely to occur?

Answer 19

Due to kidney stones attempting to pass - in the first constriction of the ureter in the pelviuteric junction

Question 20

What is the bladder’s structure?

Answer 20

Pelvic organ - triangular pyramid with apex pointing anteriorly and base posteriorly Lined by urothelium (transitional epithelium), 3-layered epithelium with very slow cell turnover, large luminal cells present

Question 21

What do luminal cells do?

Answer 21

Highly specialised low permeability luminal membrane which prevents dissipation of urine-plasma gradients

Question 22

What is the structure of the bladder? - FITB

Answer 22

Question 23

What are the 2 urinary sphincters?

Answer 23

Sphincter vesicae and sphincter urethrae

Question 24

What is the sphincter vesicae?

Answer 24

Internal sphincter, smooth muscle, neck of bladder, reflex opening in response to wall tension

Question 25

Which nervous system is the sphincter vesicae controlled by?

Answer 25

Parasympathetic

Question 26

What is the sphincter urethrae?

Answer 26

External sphincter, striated muscle, in perineum - opened by voluntary inhibition of nerves

Question 27

How is tone maintained?

Answer 27

By somatic nerves in Pudendal nerve (S2-4)

Question 28

How does the activation of the reflex control of the internal sphincter urethrae work?

Answer 28

Bladder fills, stimulates stretch receptors which stimulate parasympathetic nerves and inhibit motor neurons, the PS nerve stimulate the bladder to contract, causing internal urethral sphincter to open mechanically

Question 29

How does the activation of the voluntary control of the external sphincter urethrae work?

Answer 29

Cerebral cortex stimulates motor neurons and stretch receptors inhibit them - so motor neurons either cause, external US to open when motor neuron inhibited OR external US remains closed when motor neuron is stimulated

Question 30

How is the urethra different in males than females?

Answer 30

Females: Paraurethral gland Males: Preprostatic/ prostatic/membranous/ spongy part of urethra

Question 31

Fill in the blanks on the differences between male and female urethra differences

Answer 31

Question 32

What is the male urethra comprised of?

Answer 32

Internal urethral orifice (bladder neck/outlet), prostatic urethra, membranous urethra, bulbar urethra, penile urethra, navicular fossa, external urethral meatus

Question 33

What is the lymph drainage of the urinary system?

Answer 33

x

Question 34

Under which ribs does the spleen lie?

Answer 34

Ribs 9-10

Question 35

What are the posterior relations of the kidneys?

Answer 35

Abdominal wall: psoas major nearest to the medial side of kidney, then quadratus lumborum, and Transversus abdominis Above: diaphragm is present

Question 36

How are the aorta and IVC arranged in the abdomen?

Answer 36

Aorta is to the left and IVC is to the right in the abdomen, so left renal vein is longer and passes in front of aorta, underneath IMA Renal artery passes underneath the IVC

Question 37

What is the renal pelvis?

Answer 37

Each renal papilla is surrounded by a branch of the renal pelvis called a calyx. The major function of the renal pelvis is to act as a funnel for urine flowing to the ureter.

Question 38

What is the arrangement of the urinary system in the abdomen?

Answer 38

Question 39

How is the renal blood supply organised in the abdomen? FITB

Answer 39

X

Question 40

How does the urine drain from the kidney?

Answer 40

Urine drains into the minor calyx, then major calyx which then all drains into the renal pelvis

Question 41

From where does the ureter get its blood supply from and why does it need a blood supply?

Answer 41

Upper: from renal arteries Middle: common iliac arteries, some branches of abdominal aorta and gonadal arteries Lower: internal iliac arteries (and some others) Need it as it is a muscular tube and needs a continuous blood supply

Question 42

Where is the bladder located?

Answer 42

Usually in the true pelvis but can be in the abdomen in children and when full in adults

Question 43

What is the trigone?

Answer 43

It is a straight, not corrugated triangle shape in the bladder