Urinary System Notes Flashcards
What is acute tubular necrosis (ATN)? What is it the most common cause of?
Ischemic necrosis of tubular cells; most common cause of renal failure.
What does the afferent arteriole do?
Carries blood entering the glomerulus.
What is an angiomyolipoma?
A benign tumor composed of blood vessels, smooth muscle, and fat.
What is angiotensin? 3
Polypeptide in the blood that:
1. Causes vasoconstriction
2. Increase in blood pressure
3. Release of aldosterone.
What is Bowman’s capsule?
A cup-like structure surrounding the glomerulus.
What does the efferent arteriole do?
Carries the blood away from the glomerulus.
What is fascia?
Fibrous connective membrane of the body that may be separate from other structures.
What is Gerota’s fascia?
Protective covering of tissue surrounding each kidney.
What is glomerulonephritis?
Inflammation of the glomerulus of the kidney.
What is the glomerulus composed of?
Structure composed of blood vessels or nerve fibers.
What is a hypertrophied column of Bertin?
Enlargement of a column of Bertin that extends into the renal pyramid.
What is an infundibulum?
Portion of the collecting system composed of the minor and major calyces.
What is a medullary pyramid?
Renal pyramid.
What is a papilla?
Blunt apex of the renal pyramid.
What is a parapelvic cyst?
Fluid-filled mass of lymphatic origin located within the renal sinus.
What is pelviectasis?
Dilation of the renal pelvis.
What is renal colic?
Sharp, severe flank pain radiating to the groin.
What is renal failure?
The inability of the kidneys to excrete waste, concentrate urine, and conserve electrolytes.
What is renal insufficiency?
Partial kidney function failure characterized by less than normal urine output.
What is a renal lobe?
Portion of the kidney consisting of a single pyramid, bordered on both sides by the interlobar arteries, with cortical tissue at its base.
What is renal parenchyma?
The functional tissue of the kidney consisting of the nephrons.
What is renal sinus lipomatosis?
Excessive accumulation of fat in the renal sinus.
What is renin?
Renal enzyme that affects blood pressure.
What is a staghorn calculus?
Large stone forming in the renal pelvis and extending into some or all of the calyces.
What is a twinkle artifact?
Quick fluctuating color Doppler signal from a rough surface or highly reflective object.
What is the urachus?
Epithelial tube connecting the apex of the urinary bladder to the umbilicus.
What is a ureterocele?
Prolapse of the distal ureter into the urinary bladder.
What is the nephron?
The basic functional unit of the kidney.
What is the composition of a nephron? What is each composed of?
Composed of
1. Renal corpuscle (glomerulus, Bowman’s capsule, afferent arteriole, efferent arteriole)
2. Renal tubule (proximal convoluted tubule, loop of Henle, distal convoluted tubule).
How many nephrons does each kidney contain?
More than one million nephrons.
What are the functions of the urinary system? 5
- Produces urine and erythropoietin
- Influences blood pressure, blood volume
- intake or excretion of salt and water through the renin–angiotensin system
- Regulates serum electrolytes
- Regulates acid–base balance.
What is the renal capsule?
Fibrous capsule (true capsule) surrounding the cortex.
What is the renal cortex? What does it contain?
- Outer portion of the kidney, bound by the renal capsule and arcuate vessels
- Contains glomerular capsules and convoluted tubules.
What is the medulla?
Inner portion of the renal parenchyma where the renal pyramids lie.
What are renal pyramids?
Triangular structures with a narrow tip (apex) that sits within the minor calyx and a wider base that abuts the renal cortex; contain tubules and the loops of Henle.
What does the collecting system consist of? 2
Consists of the infundibulum and renal pelvis.
What is the column of Bertin?
Inward extension of the renal cortex between the renal pyramids.
What is the renal sinus?
Central portion of the kidney containing the major and minor calyces, peripelvic fat, fibrous tissues, arteries, veins, lymphatics, and part of the renal pelvis.
What is the renal hilum?
Contains the renal artery, renal vein, and ureter.
What is the main renal artery? Which side is longer?
Arises from the aorta; the right renal artery is longer than the left and demonstrates low-resistance blood flow.
What are segmental arteries?
Branches of the main renal artery that demonstrate low-resistance blood flow.
What are interlobar arteries?
Branches of the segmental artery that course alongside the renal pyramids.
What are arcuate arteries? What is it a branch of?
- Boundary between the cortex and medulla
- Branches of the interlobar artery located at the base of the medulla.
What are interlobular arteries?
Give rise to the afferent arteries to enter the glomerulus.
What is the main renal vein?
Formed from the junction of tributaries in the renal hilum; courses anterior to the renal artery.
What are segmental veins?
Formed by the convergence of the interlobar veins forming the main renal vein.
What are interlobar veins?
Formed by the convergence of the arcuate veins; course in between the medullary pyramids.
What are arcuate veins?
Parallel the arcuate arteries and course along the base of the medullary pyramids.
What is the anatomy of the ureter?
Tubular structure connecting the renal pelvis to the urinary bladder, measuring 25 to 34 cm in length and 4 to 7 mm in diameter.
What is the arterial supply to the ureter? 4
- Renal artery,
- Testicular or ovarian artery,
- superior vesical artery
- Hypogastric artery.
What is the anatomy of the urethra?
A small tubular structure that drains urine from the bladder; 20 cm in length in males and 3.5 cm in length in females.
What are the support structures of the kidneys? 6
- Psoas muscle
- Quadratus lumborum muscle,
- Transversus abdominis muscle
- Gerota’s fascia
- Perinephric fat
- Renal capsule.
Where are the kidneys located?
Paired bean-shaped structures lying in a sagittal oblique plane in the retroperitoneal cavity, between the first and third lumbar vertebrae.
What is a dromedary hump? Which side is most often affected?
- Cortical bulge on the lateral aspect of the kidney
- Demonstrated most often on the left.
What is a hypertrophied column of Bertin?
Enlarged column of Bertin extending from the cortex into the renal pyramids.
What is renal duplication?
Embryonic remnant of the fusion site between the upper and lower portions of the kidney.
What is agenesis?
Absence of the kidney(s); unilateral or bilateral.
What is a pelvic kidney?
Failure to ascend with development; associated with a short ureter.
What is renal ptosis?
Unusual mobile kidney that descends from the normal position toward the pelvis.
What is the size of an adult kidney?
9.0 to 12.0 cm in length, 4.0 to 5.0 cm in width, 2.5 to 3.0 cm in height.
What is the normal sonographic appearance of the renal capsule?
Well-defined echogenic line surrounding the kidney.
What is the normal sonographic appearance of the renal cortex?
Homogeneous, fine, moderate, to low-level echogenicity; less echogenic compared with the normal liver parenchyma.
What is the normal sonographic appearance of the renal medulla?
Hypoechoic triangular structures between the renal cortex and sinus; may appear anechoic.
What is the normal sonographic appearance of the renal sinus?
Hyperechoic; most echogenic.
What is the recommended preparation for a renal ultrasound?
No preparation required; adults should drink 8 to 16 ounces of water 1 hour before the examination.
What transducer frequency is recommended for adults?
3.0 to 5.0 MHz.
What transducer frequency is recommended for children?
5.0 to 7.0 MHz.
What transducer frequency may be required for obese patients?
2.0 MHz.
What is the fasting requirement for renal vessel examination?
Nothing by mouth for 6 to 8 hours before the examination.
What frequency transducers are used for adults in renal examinations?
3.0 to 5.0 MHz.
What frequency transducers are recommended for children and small adults?
5.0 to 7.0 MHz.
What frequency transducer may be required for obese patients?
2.0 MHz may be required.
What type of transducer provides a wider field of view?
Curvilinear transducers.
What are sector or vector transducers best used for?
They have a smaller footprint, great for intercostal imaging.
What patient positioning is usually recommended for adult renal examinations?
Supine, posterior oblique, or lateral decubitus position.
What is the recommended positioning for pediatric patients during renal examinations?
Prone position.
What is the benefit of the left posterior oblique (LPO) position?
Allows bowel to move away from the right kidney.
What does the subcostal or intercostal approach aid in?
Visualizing the liver and kidney relationship.
What should be included in the examination protocol for renal imaging?
Systematic approach in sagittal, coronal, and transverse planes.
What measurements should be taken during a renal examination?
Length, height, width, and cortical thickness of each kidney.
What imaging technique is used to evaluate renal vasculature?
Color Doppler imaging.
What should be documented in the examination?
Abnormalities and measurements in two imaging planes.
What is the normal range for creatinine levels?
0.6 to 1.2 mg/dL.
What is the significance of elevated creatinine levels? 3
- Indicates renal failure,
- Chronic nephritis
- Urinary obstruction.
What is the normal range for blood urea nitrogen (BUN) levels?
11 to 23 mg/dL.
What conditions can cause elevated BUN levels? 3
- Acute or chronic renal disease
- Dehydration
- Urinary stasis.
What is hematuria?
Visible or microscopic red blood cells in the urine.
What does proteinuria indicate? What is it associated with?
Abnormal amount of proteins in the urine, associated with various renal conditions.
What is the most common renal cystic disease in infants?
Multicystic dysplasia.
What is the etiology of renal abscess?
Risk factor includes diabetes and infection.
What are the clinical findings of renal cell carcinoma? (S/s) 3
- Painless gross hematuria
- Uncontrolled hypertension
- Flank pain.
What is the most common solid renal tumor in infants?
Mesoblastic nephroma.
What is the significance of the resistive index greater than 0.7?
Associated with acute renal obstruction.
What is the echogenicity of a smaller renal mass?
Hyperechoic
What are the characteristics of a focal bulge in renal contour?
Indistinct borders and hypervascular mass
What are common sites for metastasis from renal tumors? 3
- Lung
- Liver
- Long bones
What are potential complications of renal tumors? 7
- Extension into the renal vein and IVC
- Adrenal tumor
- Abscess
- Focal pyelonephritis
- Adenoma
- Angiomyolipoma
- Wilms’ tumor (nephroblastoma)
What are risk factors for Wilms’ tumor? 6
- Beckwith-Wiedemann syndrome
- Hemihypertrophy
- Sporadic aniridia
- Male prevalence
- Omphalocele
- Age 5 years or less
What are common symptoms of Wilms’ tumor? 5
- Palpable mass
- Abdominal pain
- Nausea/vomiting
- Gross or microscopic hematuria
- Hypertension
What is the typical appearance of a Wilms’ tumor on ultrasound? 4
- Predominately
- Solid
- Well-defined renal mass with variable echo pattern
- Echogenic rim
What is the echogenicity of renal cell carcinoma?
Variable echo pattern with occasional calcification (10%)
What are the common symptoms of renal cell carcinoma? 4
- Asymptomatic
- Flank pain
- Hematuria
- Hypertension
What is the sonographic appearance of renal artery stenosis? 3
- Peak systolic velocity greater than 180 cm/s
- Spectral broadening
- Absence of diastolic flow
What is renal dialysis?
A process of diffusing blood across a membrane to remove substances a normal kidney would eliminate.
What are common complications of renal transplant? 7
- Renal artery stenosis
- Renal artery thrombosis
- Primary renal vein thrombosis
- Hematoma
- Urinoma
- Lymphocele
- Abscess
What is the normal sonographic appearance of a renal transplant? 3
- Renal sinus appears hyperechoic,
- Renal cortex appears hypoechoic
- Prominent renal pyramids
What are the layers of the bladder wall? 3
- Serosa
- Muscle
- Mucosa
What is the normal bladder wall thickness when distended?
3 mm
What is bladder exstrophy?
Failure of the mesoderm to form over the lower abdomen, associated with epispadia
What is the sonographic finding of bladder diverticulum?
Anechoic pedunculation of the urinary bladder
What are common symptoms of bladder cancer? 3
- Painless hematuria
- Frequent urination
- Dysuria
What is the appearance of bladder sludge on ultrasound?
Hyperechoic focus within the urinary bladder with posterior acoustic shadowing
