Lecture 19: Urinary System

Question 0

Inferior pole of kidneys are located where?

Answer 0

1 finger width above iliac crest

Question 1

Between what levels are the kidneys located?

Answer 1

T12-L3

Question 2

Superior pole of kidneys is located where?

Answer 2

Deep to ribs 11 and 12

Question 3

Why is the right kidney lower than the left?

Answer 3

Because of the liver

Question 4

Renal fascia

Answer 4

continuous superiorly with fascia lining on the inferior surface of diaphragm.

Question 5

Renal mobility

Answer 5

During forced respiration : moves up 4cm

During quiet respiration : moves up 1 cm

Question 6

Pathway of ureter

Answer 6

Ureter passes anterior to psoas major muscle and external iliac
blood vessels.

Question 7

Left ovarian/testicular vein drains back to?

Answer 7

left renal vein

Other retroperitoneal structures drain back to IVC.

Question 8

Renal vein, artery and pelvis positioning

Answer 8

Renal vein anteriorto renal artery which is anterior to renal pelvis at the hilum.

Question 9

Blood supply to bladder

Answer 9

superior and inferior VESICLE arteries which branch from the internal iliac arteries.

Question 10

At what vertebral level do the renal arteries branch?

Answer 10

branch from abdominal aorta at vertebral level L1 posterior to pancreas.

Transpyloric line, which pancreas traverses, is also at vertebral level L1.

Question 11

Arcuate arteries

Answer 11

Arcuate arteries demarcate junction between cortex and medulla of kidney.

Question 12

Renal Innervation parasympathetic and sympathetic

Answer 12

Renal plexus travels along renal artery.
Parasympathetic: vagus nerve to kidneys
• pelvic splanchnic nerves (S2-S4; not part of sympathetic trunk!!!) to distal ureters

• Sympathetic: Lesser and least thoracic splanchnic nerves to kidneys, proximal ureters

Question 13

What are the locations in the renal system where renal stones are likely to occur?

Answer 13

Usually at points of relative constriction:

(1) junction of ureters and renal pelvis;
(2) where they cross external iliac artery & pelvic brim;
(3) where they pass through bladder wall.

Question 14

Renal stones (calculi)

Answer 14

Pain can radiate from “loin to groin”

Pain distribution reflects pathway of visceral afferents (triggered by distended ureter) that course to spinal cord levels
T11-L1 via the sympathetic splanchnic nerves.

Question 15

Female peritoneal reflections

Answer 15

Reflects from bladder to body of uterus forming VESICO-UTERINE POUCH

Reflects from vagina onto rectum forming RECTO-UTERINE POUCH

Question 16

Pelvic pain line

Answer 16

Uterine tubes, ovaries & body of uterus superior to pelvic pain line. Cervix & vagina inferior to pelvic pain line.

Superior to line: visceral afferent fibres follow sympathetic fibres back to T12-L2 spinal cord.
Inferior to line: visceral afferent fibres follow parasympathetic fibres back to S2-S4 spinal cord.

Referred pain to the dermatomes => where do you feel ovulation pain? Where do you feel pain after a pap smear? Ectopic pregnancy pain?

Question 17

Male peritoneal reflections

Answer 17

Reflects from bladder and seminal vesicles onto rectum forming
RECTO-VESICLE POUCH

Question 18

Urination 3 things need to occur?

Answer 18

1. Detrusor muscle (smooth) to contract
2. Internal urethral sphincter (smooth) to open
3. External urethral sphincter (skeletal) to open

Question 19

To pee!

Answer 19

“Yes please, I’m busting!” = parasympathetic
stimulation, sympathetic inhibition = detrusor m.
contracts, internal sphincter relaxes and opens
(in males only!), voluntarily relax levator ani m.
to open external sphincter.

Question 20

Not to pee!

Answer 20

“No thanks, I’m too busy!” = reduce
parasympathetic stimulation, increase
sympathetic stimulation, increase nerve activity
to levator ani m. (via pudendal nerve S2-S4) to
keep it contracted…more urine accumulates

Question 21

Innervation of the bladder

Answer 21

• Inferior hypogastric plexuses.
• Sympathetic fibres from IML at L1/L2 sacral splanchnic
• Parasympathetic fibres from S2-S4 via pelvic splanchnic nerves.
• Afferent sensory fibres travel back along the pelvic splanchnic nerves.

Question 22

Male urinary bladder, anterior view

Answer 22

Internal urethral sphincter
= smooth muscle (detrusor m.)

External urethral sphincter = skeletal muscle (levator ani m.)

Question 23

Trigome

Answer 23

Trigone = smooth triangular portion of bladder wall formed by
the two ureter openings and the urethra. Mesodermal origin.

Question 24

Detrusor muscle

Answer 24

Muscle fibres form the involuntary internal urtheral sphnicter which contracts during ejaculations to prevent semen entering bladder.

Question 25

Diaphragm protects posterior aspect of superior

poles of kidneys from what?

Answer 25

Ribs

Question 26

Kidneys are deep to the posterior abdominal wall

muscles in what region?

Answer 26

hypochondrium regions.

Question 27

What effect will respiration have on the kidneys?

Answer 27

Elevates them

Question 28

Function anatomy of kidney

Answer 28

Tubules extend in medulla.
• Tubules drain to collecting ducts.
• Collecting ducts form renal pyramids that drain filtrate (urine) into minor calyces.
• Minor => major calyces => renal pelvis => ureter.

Question 29

A healthy bladder can store?

Answer 29

500ml

Question 30

Male: The internal urethral sphincter is made of what muscle?

Answer 30

smooth muscle: detrusor muscle

Involuntary, controlled by ANS

Question 31

Male: The external urethral sphincter is made of what muscle?

Answer 31

skeletal muscle: levator ani muscle

Voluntary, controlled by somatic nerves

Question 32

Location of seminal vesicles

Answer 32

Seminal vesicles on posterior surface of bladder.

Urethra passes through prostrate.

Question 33

What happens to urinary flow when the prostate is enlarged?

Answer 33

Restricts urine flow

Question 34

The female has only one sphincter what is this?

Answer 34

External urethra sphincter

Question 35

Female: what muscle is the external urethral sphincter made up of?

Answer 35

skeletal muscle: levator ani muscle
Voluntary
Controlled by somatic nerves

Question 36

Implications for adult disease: reduced nephron number =>

Answer 36

High blood pressure