Urinary Anatomy

Question 1

What is contained within the Urinary system?

Answer 1

Kidneys, ureters, urinary bladder, urethra

Question 2

What are the Ureters?

Answer 2

Muscular tubes transporting urine from kidneys to the bladder; continuous with the renal pelvis - formed by the condensation of 2/3 major calices

Question 3

What is the Uteropelvic Junction?

Answer 3

Narrowing of the renal pelvis where it becomes continuous with the ureter

Question 4

What is the course of the Ureters?

Answer 4

Descend retroperitoneally on the medial aspect of Psoas major to the pelvic brim, where they cross the common iliac/proximal end of the external iliac artery to enter the pelvic cavity and enter the bladder (at the level of the ischial spine)

Question 5

What are the 3 constrictions for the Urinary system?

Answer 5

Ureteropelvic junction Point of crossing the common iliac vessels at the pelvic brim Entrance to the bladder

Question 6

How is the Renal system innovated?

Answer 6

Renal, aortic and sup/inferior hypogastric plexuses all innervate (visceral efferents from both SNS and PSNS sources - visceral afferents return to T11-L2 leading to referred pain at their dermatomes - e.g. Posterolateral abdominal wall pain)

Question 7

Where is the bladder?

Answer 7

Most anterior element of the pelvic viscera; triangular pyramid with the apex pointing anteriorly

Question 8

Describe the lining of the bladder:

Answer 8

Lined by the urothelium (3-layered membrane with slow cell turnover and large, impermeable luminal cells)

Question 9

What is the Apex of the bladder?

Answer 9

Directed towards the top of the pubic symphysis and attached to the umbilicus via the medial umbilical ligament

Question 10

Describe the base of the bladder:

Answer 10

Inverted triangle and points posteriorly; ureters enter at upper corners, with the urethra draining inferiorly from the lower corner of the base

Question 11

What does the bladder look like?

Answer 11

Question 12

What is the Trigone?

Answer 12

Smooth area between openings of ureters and urethra

Question 13

Describe the neck of the bladder:

Answer 13

Anchored in position by tough fibromuscular bands, connecting neck/pelvic part of the urethra to the posteroinferior aspect of each pubic bone

Question 14

What is the difference in the necks of the bladder in men and women?

Answer 14

• Women: pubovesical ligaments - supported by peritoneum and associated muscles
• Men: puboprostatic ligaments - blend with fibrous capsule of the prostate which surrounds the neck of the bladder

Question 15

What is the bladder reflex?

(Including motor innovation)

Answer 15

Bladder filling activates sensory PSNS stretch fibres, leading to S2-4 motor neurones to signal detrusor muscle to cause contraction and open internal sphincter

Question 16

Describe the lymphatics of the bladder:

Answer 16

Iliac nodes; with ureter drain to para-aortic nodes

Question 17

What are the two Urinary Sphincters?

Answer 17

Two are present - s. urethrae and s. Vesicae - needed to maintain urinary continence

Question 18

What is the Sphincter vesicae?

Answer 18

Internal smooth muscle sphincter at the neck of the bladder that opens reflexively in response to bladder wall tension - relaxed by PSNS and contracts due to SNS

Question 19

What is the sphincter urethrae?

Answer 19

External striated muscle sphincter in the perineum, whose tone is maintained by somatic nerves in the pudendal nerve (S2-4), opened by voluntary nervous inhibition

Question 20

Describe the Urethra of a female:

Answer 20

Short urethra, travelling inferiorly through the pelvic floor and deep perineal pouch/membrane to open into the vestibule between the labia minora; small Skene’s (mucous) glands associated with lower end

Question 21

Describe the urethra of a male:

Answer 21

Longer urethra, passes inferiorly through the prostate, through the deep perineal pouch and perineal membrane and enter the root of the penis (divided to preprostatic, prostatic, membranous and spongy parts)

Question 22

Describe a diagram of the bladder and vagina:

Answer 22

Question 23

Describe a diagram of the bladder and penis:

Answer 23

Question 24

What is above each kidney?

Answer 24

Diaphragm for Right

Spleen for left

Question 25

Which kidney is higher, and what are the surface landmarks of each kidney and the hilum?

Answer 25

Left is higher Apex of left is 11th rib, apex of right is 11th ICS Hilum = L1

Question 26

What are the anterior relations of each kidney?

Answer 26

Right: liver, hepatic flexure Left:stomach, pancreas, spleen and splenic flexure

Question 27

What is the hilum of the kidney?

Answer 27

Deep vertical slit through which the renal vessels, lymphatics and nerves enter/leave (continuous internally with the renal sinus)

Question 28

What is the renal cortex?

Answer 28

Outer layer of the kidney - continuous band of place tissue, with projections called renal columns into the inner aspect to divide the medulla to discontinuous aggregations[Granular]

Question 29

What is the Renal medulla?

Answer 29

Pyramid shaped regions of the kidneys where nephrons are present[Striated]

Question 30

What are the minor calicies?

Answer 30

Apical projections of the renal pyramids

Question 31

What is the major Calyx?

Answer 31

Unity of several minor calices - multiple major calices unite to form the renal pelvis

Question 32

Describe the renal arteries:

Answer 32

Lateral branches of the abdominal aorta that supply each kidney; arise inferior of the SMA origin at L2/3, with the left renal artery shorter and higher Branches on entering the kidney to form interlobar arteries within the columns, which then form acruate arteries that anastomose with their neighbours to supply the nephrons

Question 33

Describe the vasculature at the hilum:

Answer 33

The renal arteries divide to anterior and posterior branches to supply the parenchyma

Question 34

Describe the renal veins:

Answer 34

Are formed by multiple smaller veins, and run anterior to the arteries; left renal vein crosses anterior to aorta but posterior to the SMA, and can be compressed by aneurysms in either vessel

Question 35

Describe the afferent arterioles:

Answer 35

Have a high pressure due to proximity to aorta, and are larger than efferents to generate a pressure gradient

Question 36

Describe the renal corpuscle:

Answer 36

Glomerulus of capillaries forms, surrounded by the Bowman's capsule; filtration is provided by: Fenestrations in the capillary endothelium Specialised basal lamina Filtration slits of the podocytes that restrict passage of ions/molecules \<50k mw

Question 37

Describe the PCT:

Answer 37

Reabsorbs ions, glucose, amino acids, proteins and water; has a cuboidal epithelium sealed with tight junctions and a brush border to maximise the surface area

Question 38

Describe the Loop of Henle:

Answer 38

Descending limb has a simple squamous epithelium to allow for passive osmotic equilibration, while ascending limb has a thicker lining to actively pump out sodium ions whilst being impermeable to water, hence creating a concentrated tubular solution; supplied by the vasa recta

Question 39

Describe the DCT:

Answer 39

Have no brush border but adjusts sodium, potassium, hydrogen and ammonium ion concentration in urine using a cuboidal epithelium with few microvilli (ions controlled by aldosterone and osmosis by vasopressin)

Question 40

Describe the Collect ducts:

Answer 40

Passes through medulla, excreting to renal pelvis; reabsorbs water in response to ADH, which controls [AQP2] on the apical surface

Question 41

Describe the efferent arterioles:

Answer 41

Smaller diameter than the afferents to increase the pressure in the glomerulus and generate a pressure gradient