functional unit of the kidney
Each kidney contains more than a million nephrons.
Functions: filter waste products from the blood, reabsorb water and nutrients (e.g., glucose and amino acids) from the tubular fluid, and secrete excess substances in the form of urine.
How much water do nephrons filter each day?
In an average person, the nephron filters about 190L of water out of glomerular blood each day
Formation of urine begins here
Tuft of capillaries with very thin walls and a large surface area
substance produced by the kidney stimulates the rate of production of red blood cells
involuntary emptying of the bladder at intervals caused by cerebral hemorrhage and spinal cord injury
act of urinating
Unilateral renal agenesis
A rare congenital anomaly in which only one kidney forms
Unilateral renal agenesis image
Appears as a miniature replica of a normal kidney, with good function
hypoplastic kidney image
Abnormal position, such as in the pelvis (pelvic kidney) or high near the diaphragm (intrathoracic kidney)
ectopic kidney image
A rare anomaly in which a small, rudimentary third kidney
Functions normally, but are prone to infections that eventually may require their removal
Supernumerary kidney image
Kidneys fused at the lower poles
The most common fusion anomaly
Ureterocele is a cystic dilatation of the distal ureter
near its insertion into the bladder.
two types of ureterocele
what age group is ureterocele normally found in? What is it commonly associated with?
Found almost exclusively in infants and children Commonly associated with ureteral duplication
is a nonsuppurative inflammatory process involving the tufts of capillaries (glomeruli) that filter the blood within the kidney. Glomerulonephritis is an antigen-antibody reaction that most commonly occurs several weeks after an acute upper respiratory or middle ear infection with certain strains of hemolytic streptococci.
What is glomerulonephritis caused by?
More frequently, the inflammatory process is caused by a chronic autoimmune disorder.
What is glomerulonephritis cause?
Causes the glomeruli to be extremely permeable, allowing albumin and red blood cells to leak into the urine (resulting in proteinuria or hematuria). It causes oliguria - a smaller-than-normal amount of urine.
What is pyelonephritis? What is it caused by? What does it affect?
Pyelonephritis is a suppurative inflammation of the kidney and renal pelvis with patchy distribution. It is caused by pyogenic (pus-forming) bacteria. It affects the interstitial tissue between the tubules. It often affects only one kidney. It is asymmetric if both kidneys are involved.
Where does pyelonephritis infection originate?
Infection usually originates in the bladder, ascends the ureter to involve the kidneys.
Who is pyelonephritis more common in?
Pyelonephritis is more common in women
When does pyelonephritis develop? What is a contributing factor?
It develops in patients with obstruction of the urinary tract (enlarged prostate gland, kidney stone, congenital defect). It causes stagnation of urine - a breeding ground for infection. Instrumentation or catheterization of the ureter is also a contributing factor.
Symptoms of pyelonephritis are:
- High fever
- Sudden back pain that spreads over the abdomen
- Bacteria can be cultured from the urine or
observed in the urinary sediment
a smaller-than-normal amount of urine
pus in the urine
What is the most common nosocomial infection?
Cystitis is an inflammation of the urinary bladder.
Who is cystitis most common in? why?
It is most common in women.
Due to a shorter urethra
what is a major cause of cystitis? other?
Major: Spread of bacteria present in fecal materia
Other: Instrumentation or catheterization of the
Retrograde flow from urine bag
• Bag must be kept below the patient to prevent retrograde
Urinary frequency, urgency, and burning sensation
Urinary calculi most commonly form in the kidney as ___________.
kidney stone symptoms
They are asymptomatic until they lodge in the ureter and cause partial obstruction. This results in extreme pain that radiates from the area of the kidney to the groin.
Cause of kidney stones varies.
- Often reflect an underlying metabolic abnormality, such as hypercalcemia (resulting from hyperparathyroidism).
- Any cause of increased calcium excretion in the urine
- Urinary stasis and infection
Most accurate modality for kidney stones
what can kidney stones cause?
Can cause hydronephrosis
Blockage above the level of the bladder
Renal calculus that completely fills the renal pelvis
a condition in which calcium levels in the kidneys are increased
distention of the pelvis and calyces of the kidneys
blockage above the level of the bladder
the most common unifocal mass of the kidney.
- Fluid-filled, usually unilocular-Septa sometimes divide the cyst into chambers
- They vary in size.
- They may occur at single or multiple sites in one or both kidneys.
most common renal neoplasm
Renal cell carcinoma, also known as hypernephroma
what age group is renal cell carcinoma most common in?
It occurs predominantly in patients older than 40 years.
where does renal carcinoma originate in?
Renal carcinoma originates in the tubular epithelium of the renal cortex.
Classic symptom triad of renal cell carcinoma:
- Flank pain
- Palpable abdominal mass
the most common abdominal neoplasm of infancy and childhood.
Wilms’ Tumor (Nephroblastoma)
Where does Wilms' Tumor arise from?
It arises from embryonic renal tissue.
What does Wilms' Tumor appear as?
It may be bilateral.
It tends to become very large and appear as a palpable mass.
who is renal vein thrombosis most common in?
Renal vein thrombosis occurs most frequently in children who are severely dehydrate.
modality of choice for renal vein thrombosis
what is the main reason for adults to get renal vein thrombosis?
In adults, is most often a complication of another renal disease
Rotation on the longitudinal or horizontal axis; asymptomatic
An ectopic kidney lies on the same side as the normal kidney and is very commonly fused
Complete fusion and varied names
A rare anomaly that produces a single irregular mass has no resemblance to a renal structure
Varied names - disk, cake, lump, and doughnut kidney
Duplication (duplex kidney)
A common anomaly that varies from a simple bifid pelvis to a completely double pelvis, ureter, and ureterovesical orifice.
what can complete duplication of the kidney be complicated by?
Complete duplication can be complicated by obstruction or by vesicoureteral reflux with infection.
Posterior Urethral Valves
- Posterior urethral valves are thin transverse membranes in the urethra.
- Found almost exclusively in males
- Cause bladder outlet obstruction
- They may lead to severe hydronephrosis, hydroureter, and renal damage.
What is posterior urethral valves best demonstrated on?
This is best demonstrated on a voiding cystourethrogram.
What is renal tuberculosis? How is it spread?
Renal tuberculosis usually occurs as a secondary infection from lung involvement Hematogenous spread It can evolve from other sites.
When does renal tuberculosis manifest?
manifests 5 to 10 years after the primary infection.
What may renal tuberculosis lead to the development of?
It may lead to the development of small granulomas scattered in the cortical portion of the kidneys.
is a destructive process involving a varying amount of the medullary papillae and the terminal portion of the renal pyramids.
Predisposing factors include of papillary necrosis:
- Urinary tract infection
- Urinary tract obstruction
- Sickle cell disease
- Phenacetin abuse
Polycystic kidney disease
an inherited disorder in which multiple cysts of varying size cause lobulated enlargement of the kidneys and progressive renal impairment.
One-third of patients with polycystic kidney disease also have? Does it interfere with hepatic function?
One-third of patients also have liver cysts.
Do not interfere with hepatic function
Complications of polycystic kidney disease
About 10% have one or more saccular (berry) aneurysms of cerebral arteries
May rupture and produce a fatal subarachnoid hemorrhage
Many are hypertensive.
how is polycystic kidney disease diagnosed? why?
Most tend to be asymptomatic during the first three decades of life
Early diagnosis is made either by chance or by specific search due to family history
where does carcinoma of the bladder most commonly originate?
most commonly originates in the epithelium.
what is carcinoma of the bladder referred to as? who is it most common in?
It is referred to as urothelial carcinoma
Previously - transitional cell carcinoma
It is most common in men over age 50.
It is the fourth most common cancer in men.
predisposing factors of bladder cancer:
- Industrial chemicals
- Cigarette smoking
• Presumably due to carcinogenic metabolites being excreted in urine
what is acute renal failure? what does it result in?
Acute renal failure is a rapid deterioration in kidney
It results in the accumulation of nitrogencontaining wastes in the blood.
It causes a characteristic urinelike odor or “fishy” breath.
Two types of acute renal failure:
Prerenal failure causes include:
- Decreased blood flow to the kidneys (hemorrhage, dehydration, surgical shock)
- Cardiac failure
- Renal artery obstruction
Postrenal failure causes:
Urine outflow obstruction from both kidneys
• Prostatic disease
• Functional obstruction of the bladder neck
Other causes of acute renal failure:
- Kidney diseases, such as glomerulonephritis, bilateral acute pyelonephritis, and malignant (severe) hypertension
- Nephrotoxic agents (antibiotics, radiographic contrast material, anesthetic agents, heavy metals, organic solvents)
- Intravascular hemolysis
- Large amounts of myoglobin (muscle protein) in the circulation from muscle trauma or ischemia
what makes chronic renal failure reflect?
may reflect prerenal, postrenal, or intrinsic kidney disease.
Causes of chronic renal failure include:
- Bilateral renal artery stenosis
- Bilateral ureteral obstruction
- Intrinsic renal disorders, such as chronic glomerulonephritis, pyelonephritis, and familial cystic diseases
stable concentration in body fluids
cup-shaped end of renal tubule
funnels urine into the papillary ducts in the renal pelvis
occurs in the kidneys and produces a single irregular mass that has no resemblance to a renal structure
equilibrium of electrolytes in the body
dilation of the ureter
most common renal cell carcinoma
kidney located in the thoracic cavity
loop of henle
U-shaped portion of the renal tubule
calcium deposits within the substance of the kidney
kidney located in the pelvis
proximal convoluted tubule
second part of the Nephron, first part of renal tubule
an extra kidney
triangular area of the posterior bladder, between the opening of the ureters and urethra
presence of excessive amounts of urea and nitrogen in the blood