Outer cortex: contains the glomeruli

Inner medulla: contains the tubules and  collecting ducts

What are the calyces?

What is their function?

Join to form the renal pelvis

Recieve urine from the collecting ducts

Continuous with the upper end of the ureter

The urine forming unit of the kidney

Composed of:

- glomerulus

- proximal tubule

- hairpin loops of Henle

- distal tubule

- collecting duct

Contains loops of capillaries

These capillary walls serve as a filtration membrane for the formation of the primary urine. 

The layers include the endothelium, basement membrane, and epithelium

Mesangial cells and matrix

Secrete renin and are located around the afferent arteriole

They are contiguous with sodium-sensing macula densa cells of the distal convoluted tubule

The space between the visceral and parietal epithelium

Microvilli: increase surface area and enhance reabsorption

Sodium and water

Contributes to the hypertonic states of the medulla

It adjusts the acid-base balance by excreteing acid into the urine and forming new bicarbinate ions

Contain principal cells that resorb sodium and water and excrete potassium 

Also contain intercalated cells that secrete hydrogen or bicarbinate and potassium

Extend from the renal pelvis to the posterior wall of the bladder

Urine flows through the ureters by means of peristaltic contractions of ther ureteral muscles

Composed of the detrusor and trigone muscles and innervated by parasympathetic fibers

When accumulation of urine reaches 250 to 300ml, mechanoreceptors, which respond to stretching of tissue stimulate the micturation reflex.

Blood flows at about 1000-1200ml/min, or 20% to 25% of the cardiac output.

Regulated by autoregulation

Is the filtration of plasma per unit of time and is directly related to the perfusion pressure of renal blood flow

• Autoregulation of RBF
• Sympathetic neural regulation of  vasoconstriction

They are innervated by the sympathetic noradrenergic nerves that regulate vaso constriction

It causes the generation fo angiotensin I, which is converted to angiotensin II by the action of ACE. 

Angiotensin II stimulates release of aldosterone from the adrenal cortex and is a potent vasocanstrictor. Thus the RAAS system is a regulator of renal blood flow and blood pressure

They promote sodium and water loss by inhibiting aldosterone and increasing sodium chloride excertion

Urine formation, which involves the processes of glomerular filtration, tubular reabsorption, and tubular secretion and excretion

Favored by capillary hydrostatic pressure and opposed by oncotis pressure in the capillary and hydrostatic pressure of the Bowman capsule

The balance of favoring and opposing filtration forces is the NFP

Approx 120ml/min

99% is reabsorbed

Reabsorbs about 60%-70% of the filtered sodium and water and 90% of other electrolytes

Most molucules are reabsorbed by active transport. Therefore the carrier mechanism can become saturated at the Tm. 

Molucules not reabsorbed are excreted with the urine

Actively resorbs sodium and secrete potassium and hydrogen for the regulation of electrolyte and acid-base balance

A function of the level of ADH that stimulates the distal tubules and cellecting ducts to reabsorb water

The countercurrent exchange system of the long loops of Henle and their accompanying capillaries establishes a concentration gradient within the renal medulla to facilitate the reabsorbtion of water from the collecting duct

It regulates the acid-base balance by excreteing hydrogen ions and forming new bicarbonate

Vit D3

Erythropoietin

Tests that indicate how much of a substance can be cleared from the blood by the kidneys per given amount of urine

Measure in plasma and urine to calculate a commonly used clinical measurement of GFR

Creatinine is produced by muscle

Plasma creatinine and cystatin C are measured to monitor progressive renal dsyfunction

BUN is an indicator of hydration status

Used to determine renal plasma flow and blood flow

color

turbidity

protein

pH

specific gravity

sediment

supernatant

Presence of:

bacteria

red blood cells

white blood cells

casts

crystals

Obstructions:

Where can an obstruction occur?

Can occur anywhere in the urinary tract

May be anatomic or functional

Examples:

renal stones

enlarged prostate gland

urethral strictures

Obstructions:

What are complications of obstruction?

Hydronephrosis

Hydroureter

Ureterohydronephrosis

Infection d/t the accumulation of urine behind the obstruction

Obstruction:

What are the compensatory mechanisms?

Hypertrophy and hyperperfusion of the opposite kidney compensate for loss of function

Obstruction:

What happens when the obstruction is relieved?

Postobstructive diuresis which may cause fluid and electrolyte imbalance

Obstruction:

What does an persistant obstruction lead to?

May lead to residual urine volumes, low bladder wall compliance, and risk for vesicoureteral reflux and infection

Obstruction:

What causes kidney stones?

Caused by supersaturationof the urine with precipitation of stone-forming substances

Changes in pH

UTI

Most stones are unilateral

Obstruction:

What is the most common form of kidney stone?

A stone formed from calcium oxylate

Usually lodges in the ureter

Obstruction:

What causes obstructions of the bladder?

Usually caused by neurogenic or anatomic alterations or both

Obstructions:

What is an upper motor neuron lesion and what does it result in?

A lesion above the pontine micturition center

Results in detrusor hyperreflexia and an uninhibited or reflex bladder

Obstructions:

What causes a neurogenic bladder?

Caused by a neural lesion that interrupts innervation of the bladder

Obstructions:

What does an upper motor neuron lesion between C2 and S1 result in?

Results in overactive or hyperrelexive bladder function and vesicosphincer dyssynergia

(lack of coordinated neuromuscular contraction)

Obstructions:

What does a lower motor neuron lesion result in?

Detrusor areflexia with underactive, hypotonic, or atonic bladder function

Obstructions:

OAB (overactive bladder) syndrome is what?

An uncontrolled or premature contraction of the bladder that results in urgency with or without incontinence, frequency, and nocturia

Obstructions:

What are anatomic obstructions?

Prostatic enlargement

Urethral stricture

Pelvic organ prolapse

Obstructions:

What can a partial obstruction of the bladder result in?

Overactive bladder contractions with urgency

There is a deposition of collagen in the bladder wall over time, resulting in decreased bladder wall compliance and ineffective detrusor muscle contraction

Renal cell carcinoma

Most common renal neoplasm. 

The larger neoplasms tend to metastasize to the lung, liver, and bone

Commonly composed of transitional cells with a papillary appearance and a high rate of recurrence

UTI's:

What is most common cause?

By the retrograde movement of bacteria into the urethra and bladder

UTI's:

What is the difference between uncomplicated and complicated?

Uncomplicated = urinary system is normal

Comlicated= there is a defect or    abnormality

UTI's:

What is cystitis?

An inflammation of the bladder caused by bacteria and may be acute or chronic

UTI's:

Painful bladder syndrome

Intersitial cystitis

Includes:

Nonbacertial infectious cystitis - viral, mycobaterial, chlamydia, fungal

Noninfectious cystitis - radiation injury

Intersitial cystitis - autoimmune injury

UTI's:

What is pyelonephritis?

(acute and chronic)

Inflammation of the renal pelvis often related to ascending infection and obstructive uropathies and may cause abscess formation and scarring with an alteration in renal function

Glomerular Disorders

What are they?

A group of related diseases that can be caused by immune injury, toxins or drugs, vascular disorders, and other systemic diseases

Glomerular Disorders

What are the causitive factors of acute glomerulonephritis?

Results from inflammatory damage to the glomerulus as a consequence of immune reactions including deposition of circulating immune comlexes, antibodies reacting in-situ to planted antigens, and antibodies directed against the glomerular basement membrane

Glomerular Disorders

What will show in the urine sediment?

May contain large amounts of protein (nephrotic sediment) or have red and white blood cells and protein (nephritic sediment)

Glomerular Disorders

Acute postinfectious glomerulonephritis is commonly associated with what?

Immune complex deposition in the glomerulus or forming in situ

Glomerular Disorders

Lupus nephritis is caused by what?

The formation of autoantibodies against dsDNA and nuleosomes in the glomerulus, causeing inflammation and injury

Glomerular Disorders

IgA nephropathy

The binding of abnormal IgA to mesangial cells in the glomerulus resulting in injury and mesangial proliferation

Glomerular Disorders

RPGN is associated with what

With injury that results in the proleferation of glomerular capillary endothelial cells and a rapid loss of renal function

Glomerular Disorders

What does mesangial proliferative glomerulonephritis involve?

Involves the deposits of immune complexes in the mesangium with mesangial proliferation leading to nephritic syndrome

Glomerular Disorders

What is membranous nephropathy?

A complement-mediated glomerular injury with increased glomerular permeability and glomerulosclerosis

Glomerular Disorders

Membranoproliferative glomerulonephritis involves?

Mesangial cell proliferation, complement deposition, and crescent formation

Glomerular Disorders

Chronic glomerulonephritis is related to?

A variety of diseases that cause deterioration of the glomerulus and a progressive loss of renal function over a period of months to years

Glomerular Disorders

What is nephrotic syndrome?

Excretion of at least 3.5g protein (primarily albumin) in the urine per day.

Primarily because of glomerular injury with incresed capillary permeability and loss of membrane negative charge. 

The principal signs are hypoproteinuria, hyperlipidemia, and edema

The liver cannot produce enough protein to adequately compensate for urinary loss

Acute Kidney Injury

What is it?

The sudden decline in kidney function with decreased glomerular filtration and an increase in serum creatinine and BUN

Acute Kidney Injury

What are the three categories?

Prerenal

Intrarenal

Postrenal

Usually accompanied by oliguria with elevated plasma BUN and plasma creatinine levels

Acute Kindey Injury

What is prerenal failure caused by?

A decrease in renal perfusion with a drecrease in GFR, ischemia, and tubular necrosis

Acute Kidney Injury

What is intrarenal acute renal failure associated with?

Several systemic diseases, but is commonly related to ATN (acute tubular necrosis)

Acute Kidney Injury

Postrenal acute renal failure

Associated with diseases that obstruct the flow of urine from the kidneys

Chronic Kidney Disease

What is it?

A progressive loss of renal function

Plasma creatinie levels gradually become elevated as GFR declines

Sodium is lost in the urine

Potassium is retained

Acidosis develops

Calcium metabolism and phosphate metabolism are altered

Erythropoietin producion is diminished

All organs systme are affected by CRF

Chronic Kidney Disease

When do symptomatic changes happen?

Do not become evident until renal function declines to less than 25%

Chronic Kidney Disease

What are the pathologic changes of chronic renal injury?

Glomerular hypertension, hyperfiltration, tubulointerstitial inflammation and fibrosis contribute to the progression of disease

Proteinuria and angiotensin II promote the pahtologic changes of chronic injury

Chronic Kidney Disease

What is uremic syndrome and what does it affect?

A proinflammatory state with the accumulation of solutes; toxins; and alterations in fluid, electrolyte and acid-base balance

All organ systems are affected and contribute to disease symptoms