Intro to Urinary System

Upper Urinary System

Kidneys and ureters

Lower urinary system

Urethra and bladder

Where are the kidneys located?

Retroperitoneal cavity

Anterior to the right kidney

R adrenal gland, liver, Morison’s pouch, C loop of duodenum and right colic flexure

Anterior to the left kidney

Left adrenal gland, spleen, stomach, pancreas, left colic flexure and coils of jejenum

Posterior to right kidney

Back muscles, 12th rib, and diaphragm

Posterior to left kidney

Diaphragm, 11-12th ribs, back muscles

Which kidney lies slightly lower than the other and why?

The right kidney lies slightly lower than the left due to the liver's pushing it inferiorly.

Kidneys move how with respiration?

About 1 inch down

Length of kidney should be

9-12cm

Width of kidney should be?

5cm

AP of kidney should be?

2.5cm

Which kidney is slightly longer, but how many cm in length should they be to each other?

Left, 2cm

2 parts of kidneys

Renal parenchyma and renal sinus

2 parts of renal parenchyma

Renal medulla and renal cortex

Functioning renal tissue

Renal parenchyma

What part of the renal parenchyma is outermost and responsible for filtration of blood?

Renal cortex

What part of the renal parenchyma is innermost and responsible for absorption?

Renal medulla

Renal sinus includes

Collecting system, renal vessels, fat, nerves and lymphatics

The collecting system is compromised of what?

Minor and major calyces and renal pelvis

Hilar structures A to P

Vein, artery, ureter

Hilar structures P to A

Ureter, Artery, Vein

Pathway of Urine

Parenchyma, minor calyces, major calyces, renal pelvis, ureter, bladder, urethra

Inner to Outer parts of kidneys (4)

Renal capsule, perirenal fat, Gerota’s fascia, pararenal fat

Renal capsule purpose

Surrounds kidney itself

Perirenal fat

Covers renal capsule

Gerota’s fascia

surrounds kidney and adrenal gland

Pararenal fat

surrounding fat

Functional unit of the kidney

Nephron

Two main structures of a nephron

Corpuscle and tubule

Where are nephrons located?

In the cortex and medulla

Renal corpuscle

Network of capillaries (glomerulus) surrounded by a cuplike structure (Bowmans capsule)

Afferent arteriole

Blood flow into the glomerulus

Efferent arteriole

Blood flow from glomerulus

Flow from renal proximal convoluted tubule to distal convoluted tubule

Proximal convoluted tubule, loop of Henle, distal convoluted tubule

Urine from the distal convoluted tubules of several nephrons does what next?

Drains into a collecting duct

What is the relationship between kidneys and BP?

Kidneys play a large part in BP regulation

Where do ureters enter the urinary bladder?

Posterolaterally via the trigone

Two urinary structures not typically seen on US?

Ureter and urethra

Vascular supply of kidneys

Aorta, renal artery, anterior and posterior branches, segmental, interlobar, arcuate, interlobular, afferent arterioles

Where does the renal artery become the larger anterior and small posterior artery?

At hilum

Where do the segmental arteries divide?

In sinus

Where do interlobar arteries divide?

Between pyramids

Where do the arcuate arteries divide?

At base of pyramids

Where do the interlobular arteries divide?

in cortex

Where do the afferent arterioles divide?

to nephron

What is special about the RRA?

It is the longest vessel and only vessel to run posterior to the IVC

Renal veins drain into where?

IVC

Renin

enzyme that controls BP

Physiology of kidneys

Filter blood, excrete waste via urine, absorption and regulate BP

Formation of urine involves what three processes within the nephron?

Glomerular filtration, tubular reabsorption and tubular secretion

What organs have excretion functions?

Skin, lungs, liver, large intestines and kidneys

Main metabolic waste products include

Water, carbon dioxide, and nitrogenous wastes (Urea, uric acid and creatinine)

Blood tests for renal disease

BUN, GFR, Serum creatinine and WBC count

Blood urea nitrogen (BUN) will be affected by kidney dysfunction how

Will increase

Glomerular filtration rate (GFR) will be affected by kidney dysfunction how

Will decrease

Serum creatinine will be affected by kidney dysfunction how?

Will increase

WBC count will be affected by kidney infection how

Will increase

Urine tests for renal disease

Urinalysis, Urine pH, Specific gravity, blood, protein, creatinine clearance and urine culture

Hydronephrosis

Fluid in collecting system

Normal cortex thickness shoudl be

Greater than or equal to 1cm

Medullary pyramids appear how on US?

Hypoechoic

How should the renal cortex appear relative to the liver parenchyma?

Isoechoic or slightly hyperechoic

Renal detail may be obscured if the patient has

Hepatocellular disease, gallstones, rib interference or other abnormal collection between liver and kidney

Prominent columns of Bertin may be confused with

avascular renal neoplasms

Dromedary Hump

bulge of cortical tissue that can occur on the mid/lateral border of the kidney

Dromedary humps primarily occur on which kidney?

Left

What is the echogenicity of the dromedary hump compared to the rest of the renal cortex?

Isoechoic

Junctional Parenchymal Defect

triangular, echogenic area typically located anteriorly adn superiorly

Where does a Junctional Parenchymal Defect affect, and does it affect function?

Cortex and no

Fetal Lobulation may persist in up to what percent of adults?

51%

Fetal Lobulation

surfaces of kidneys are generally indented in between calyces

Sinus Lipomatosis

Deposition of moderate amount of fat in renal sinus, with parenchymal atrophy

Extrarenal Pelvis

Tends to be larger than normal renal pelvis and located outside of the sinus medial to the hilum

Unilateral Renal Agenesis will result in

compensatory hypertrophy

Renal hypoplasia

Underdeveloped, small kidney

Horseshoe Kidney

Kidneys are fused at inferior poles, connecting isthmus is seen anterior to aorta

Double/Duplicated Collecting System

Division of renal sinus, results in an upper and a lower collecting system

Which collecting system is more likely to develop hydronephrosis and back up if there is a duplicated collecting system?

Upper

What is the most common congenital anomaly of the urinary tract?

Double collecting system

Ectopic kidney

Kidney is not where it is supposed to be but still functions normally

What is the most common location for an ectopic kidney?

Pelvis

Cake Kidney

Fused kidneys in renal pelvis, not very common

What should the texture of the bladder wall be?

Smooth

What should the bladder wall measure?

3-6 mm

What is used to examine the bladder due to being the best type of detection for early neoplasms?

Cytoscopy

Transabdominal sonography will allow visualization of most lesions greater than what?

5 mm

Stricture

Narrowing

Ureteral strictures may result from

Inflammatory disease, TB, impacted urogenital stone, localized periureteral fibrosis, schistosomiasis, iatrogenic ureteral injury or radiation therapy

Ureterocele

Cyst-like enlargement of the lower end of the ureter, typically congenital