1. The urinary system

Question 1

What is the urinary tract comprised of?

Answer 1

Kidneys
Ureters
Urinary bladder
Urethra

Question 2

Positioning of the kidneys

Answer 2

Retroperitoneal in upper abdomen
Surrounded by dense fibrous capsule
Capsule surrounded by renal fascia containing peri-renal adipose tissue

Question 3

Right kidney in relation to left kidney

Answer 3

Right kidney is usually slightly lower than the left
Superior pole of R kidney: level of 11th intercostal space
Superior pole of L kidney: at the 11th rib

Question 4

Where does the hilum to each kidney lie?

Answer 4

Hilum lies at about the level of L1

R and L- despite them being at different levels

Question 5

What splits around the kidney to form the renal fascia?

Answer 5

Transversalis fascia

Question 6

What else is enclosed in the renal fascia?

Answer 6

Adrenal glands
Perinephric fat
Great vessels

Question 7

Spleen in relation to kidneys

Answer 7

Spleen is superior and lateral to the left kidney

Question 8

Describe the posterior relations of the kidneys

Answer 8

Superior: related to diaphragm
Lateral: Transversus abdominus
Medially: quadratus lumborum and psoas major

Question 9

Anterior relations of the right kidney

Answer 9

Liver
Hepatic flexure of colon
Hilus lies behind 2nd part of duodenum

Question 10

Anterior relations of the left kidney

Answer 10

Stomach
Pancreas
Spleen
Splenic flexure

Question 11

How much of the resting cardiac output do the kidneys require?

Answer 11

20-25%

Question 12

What drives ultrafiltration?

Answer 12

Blood pressure

Question 13

How is blood delivered under high pressure to the kidneys?

Answer 13

Abundant blood supply via renal arteries: short, direct branches from abdominal aorta

Question 14

Where do renal veins drain?

Answer 14

IVC

Question 15

IVC and aorta in relation to midline

Answer 15

Aorta: Left of midline
IVC: Right of midline

Question 16

Describe the length and positioning of right renal artery

Answer 16

Right renal artery is longer than left

Passes behind IVC

Question 17

Describe the length and positioning of left renal vein

Answer 17

Left renal vein is longer than right

Anterior to aorta, but inferior to superior mesenteric artery

Question 18

How would an aneurysm in the aorta impact the kidneys?

Answer 18

Occlude flow from left kidney into IVC

Question 19

List the branches of the aorta in the abdomen

Answer 19

Celiac trunk
Superior mesenteric artery
Renal arteries on either side
Gonadal arteries
Inferior mesenteric artery

Question 20

How do the gonadal veins drain?

Answer 20

Asymmetrically
Right: Directly into IVC
Left: Drains into renal vein, which drains into IVC

Question 21

Where does each lobe of the kidney drain to?

Answer 21

Minor Calyx

Question 22

What do minor calyces form in the renal sinus?

Answer 22

Major Calyx

Question 23

What do major calyces enter into?

Answer 23

Renal Pelvis

Question 24

How is the kidney formed embryologically?

Answer 24

It is formed from ~10 kidney like units

Question 25

What divides the renal medulla into discontinuous renal pyramids?

Answer 25

Renal columns

Question 26

Describe a renal pyramid

Answer 26

Bases: directed outwards towards renal cortex Apex: projects inwards towards the renal sinus

Question 27

What do apical projections (renal papillae) contain?

Answer 27

Contains openings of the pappilary ducts draining the renal tubules Surrounded by minor calyces

Question 28

Accessory arteries and ureters in the kidney

Answer 28

Relatively common | Failing of developmental process of everything to coalesce

Question 29

Describe the layers/ pathway through the kidney

Answer 29

``` Renal Cortex Renal papilla Minor calyx Major calyx Renal pelvis Ureter ```

Question 30

Why is the renal cortex granular looking?

Answer 30

Because of its random organisation

Question 31

Why is the renal medulla striated?

Answer 31

Because of radial arrangement of tubules and microvessels

Question 32

Describe the pattern of ureter descent

Answer 32

Run vertically down posterior abdominal wall in the vertical plane of the tips of the transverse processes of the lumbar vertebrae Cross the pelvic brim anterior to the sacro-iliac joint and over the bifurcation of the common iliac arteries Descend into pelvis proper anteromedially to enter bladder at the level of the ischial spine

Question 33

Where do ureters take blood supply from?

Answer 33

``` Every major vessel they cross: Renal arteries Gonadal arteries Common iliac Internal iliac arteries and its branches (May also take some from aorta) ```

Question 34

How does fluid move through the ureters? What does this require?

Answer 34

Peristalsis | Smooth muscle walls

Question 35

Where do ureters open?

Answer 35

Open obliquely through bladder wall

Question 36

List the 3 sites of ureteric constriction

Answer 36

Pelviureteric junction Where ureter crosses pelvic brim Where ureter traverses bladder wall

Question 37

What are the ureteric constrictions sites of?

Answer 37

Sites of renal colic caused by kidney stones attempting to pass

Question 38

Ureter epithelium

Answer 38

Transitional epithelium Has tight junctions over it: urine cant pass out When there is no urine passing through it individual cells move over each other giving a layered appearance (almost like stratified squamous, but these layers can still separate)

Question 39

How is the bladder classified as an organ in children and adults?

Answer 39

Adults: Pelvic organ Children: Abdominal organ

Question 40

Shape of bladder

Answer 40

Triangular pyramid with apex pointing anteriorly and base posteriorly

Question 41

Bladder epithelium

Answer 41

Urothelium (transitional epithelium)

Question 42

Describe urothelium in the bladder

Answer 42

3-"layered” epithelium with very slow cell turnover When it stretches it becomes smooth Large luminal cells have highly specialised low-permeability luminal membrane: prevents dissipation of urine-plasma gradients

Question 43

Superior surface of bladder

Answer 43

Relatively flat | May become rounded when full

Question 44

What prevents back flow of urine into the kidney?

Answer 44

Valve at meeting point between each ureter and the bladder

Question 45

Describe the triangle that is formed by the entrance of ureters and exit of ureter

Answer 45

Trigone Smooth area Uroepithelium highly stretched and tightly adherent to layer below

Question 46

Urethra in females

Answer 46

Relatively short ~4cm Straight Held in place by pubovesical ligaments Urethra passes through perineal membrane

Question 47

Urethra in males

Answer 47

Longer Bladder separated from perineal membrane by prostate gland and puboprostatic ligament Urethra runs through prostate and through urogenital diaphragm

Question 48

How many urinary sphincters are there?

Answer 48

``` 2 Sphincter vesicae (internal sphincter: smooth muscle) Sphincter urethrae (external sphincter: striated muscle) ```

Question 49

Describe the Sphincter vesicae

Answer 49

``` At neck of bladder Reflex opening In response to bladder wall tension Relaxed by parasympathetic NS Contracts by sympathetic NS ```

Question 50

Describe the Sphincter urethrae

Answer 50

``` In perineum (in urogenital diaphragm) Tone maintained by somatic motor nerves in pudendal nerve (S2, 3, 4) Opened by voluntary inhibition of these nerves: voluntary inhibition must be learned ```

Question 51

Why is catheterising a male is more difficult?

Answer 51

There are 2 right angles and possibly a couple of constrictions

Question 52

Describe the male urethra layers

Answer 52

``` Starting at the bladder Internal urethral orifice Prostatic urethra Membranous urethra (where external sphincter is) Bulbar urethra Penile urethra Navicular fossa External urethral meatus ```

Question 53

Describe the lymphatic drainage of the urinary system

Answer 53

Lymph drainage follows arterial supply (but goes in opposite direction) Lymph drainage from bladder goes into nodes near internal iliac, common iliac, up ureters, nodes are implicated at gonadal arteries, inferior mesenteric, superior mesenteric and renal= paraaortic nodes