Kidneys
produce urine
-Paired, bean-shaped organs below diaphragm adjacent to vertebral column
-Excretory organs, functions along with lungs in excreting waste products of food metabolism
Excretory Duct system (way out of body)
Renal pelvis & ureters
renal pelvis
expanded upper portion of ureter
ureters
conveys urine into bladder by peristalsis
bladder
- stores urine into urethra during voiding
- discharges urine into urethra during voiding
- anatomic configuration of bladder & ureters normally
prevent reflux
of urine into ureters
Urethra
conveys urine from bladder for excretion
Trigone
increases pressure & helps seal off ureters during voiding to prevent reflux
3 functions of kidneys
1. excrete waste products from food metabolism
2. regulate mineral & H2O balance
3. ????????
excrete waste products from food metabolism
- CO2 & H2O: end-products of carbohydrate and fat metabolism
- Urea & other acids: end-products of protein metabolism that only the kidneys excrete
regulate mineral & H2O balance
Excretes excess minerals and H2O ingested and conserving them as required
- Erythropoeitin
- Renin
Erythropoeitin
regulated RBC production in marrow
Renin
helps regulate blood pressure
Nephron
basic
structural and functional unit of the kidney
- About 1 million nephrons per kidney
- Consists of (1) glomerulus & (2) renal tubule
Glomerulus
- Tuft of capillaries
- Material filtered from blood through glomerular capillaries into Bowman's Capsule
Renal Tubules
-
Proximal end (bowman's capsule)
invaginated by glomerulus
-
Distal end
empties into collecting tubules
- Selectively
reabsorb substances that need to be conserved (water)
- Secretes unwanted materials
- Regulates H2O balance
Nephron Requirements for Normal Renal Function
Free
flow of blood
through glomerular capillaries
- Normally
glomerular filter
that restricts passages of blood cells and protein - need to keep in blood
-
Normal tube functioning
- Normal
outflow function
: Obstructed - system backs up & doesn't work
Glomerulonephritis
inflammation of the glomeruli caused by antigen-antibody reaction within the glomeruli
-Leukocytes release lysosomal enzymes that cause injury to glomeruli
Immune-Complex Glomerulonephritis
Usually follows a
beta-streptococcal infection
- Circulating antigen and antibody complexes are trapped in glomeruli and incite
inflammation
-Most patients
recover spontaneously
without residual kidney damage
-Also occurs in SLE
Anti-Glomerular Basement Membrane (anti-GBM) glomerulonephritis
less serious
- Autoantibodies attack glomerular basement membrane
Attacking self - causes inflammation
- May also injure pulmonary capillaries causing pulmonary hemorrhage
Glomerulonephritis Symtpoms
-Urinary output is reduced
-Waste products are retained
-Plasma protein and RBC leak into urine
- Frequently forming casts
Casts
Clumps of protein and RBC's tubular in shape
Treatment Glomerulonephritis
-Supportive care
-Dialysis if needed (severe cases)
Nephrotic Syndrome
Excessive loss of protein in the urine
Nephrotic Syndrome Cause by...
injury to glomerulus
that allows protein to leak out into urine
-
Urinary excretion of protein > protein production
-Protein level in blood falls
- Causes edema due to low plasma osmotic pressure
Nephrotic Syndrome may result from
-Glomerulophritis
-Diabetic neuropathy
-Connective tissue disease, EX) SLE
Symtpoms of Nephrotic Syndrome
-Marked leg edema
-Ascites
-Pleural effusions
Prognosis Nephrotic Manifestation
-In children due to minimal glomerular change (minimal change disease)
- Responds to corticosteroids***
- Complete recovery ***
-In adults usually manifestation of severe progressive renal disease
Arteriolar Nephrosclerosis
complications of severe hypertension
-Renal arterioles undergo thickening from carrying blood at a much higher pressure than normal
-Glomeruli and tubules undergo secondary degenerative changes causing
narrowing of lumen & reduction in blood flow
- Reduce
Diabetic Nephropathy
complication of long-standing
diabetes mellitus
-Nodular and diffuse
thickening of glomerular basement membranes
(glomerulosclerosis), usually with coexisting nephrosclerosis
-MOST COMMON 40% kidney failure
Manifestation of Diabetic Nephropathy
Progressive impairment or renal function
-Protein loss may lead to nephrotic syndrome
Treatment Diabetic Nephropathy
No specific treatment can arrest progression of disease
- Control hyperglycemia has been shown to be a major determinant of the progression
- Maintaining glucose levels as much as possible to delay decline
-Progressive impairment of renal function may lea
Gout- Associated Nephropathy
person with gout who has
increase insoluable uric acid in blood & body fluid
- periodic episodes of acute
joint inflammation
Pathogenesis Gout- Associated Nephropathy
-Elevated blood uric acid levels lead to increased uric acid in tubular filtrate
-Urate may precipitate in Henle's loop and collecting tubules
-Tubular obstruction causes damage
Manifestation of Gout-associated nephropathy
-Impaired renal function
-May lead to renal failure
-Common in poorly-controlled gout
Urinary Calculi
stones may form anywhere in the urinary tract
-Most composed or
uric acid or calcium salts(calcium oxalate)
predisposing factors urinary calculi
-Increased concentration of salts in urine
-UTI
-Urinary tract obstruction- Stagnant urine
HUGE KIDNEY STONE
- small stones may be passed or impacted
Symptoms Urinary Calculi
-
Renal colic
( pain comes & goes with peristalsis start & stop)
- Paroxysms of intense flank pain radiating to the groin
-
Hematuria
-Obstruction of urinary tract causes
hydronephrosis
- dilate parts of the urinary tract
Treatment Urinary Caliculi
-
Analgesics
(sooth urinary tract)
-
Hydration
-
Cystoscopy
to snares and removes lodged stones ( if in lower region)
-
Shock waves lithotripsy
to break up stones- Shatter stones into smaller pieces
-
Surgery
(higher region)
Renal Tubular Injury
renal tubular injury in the absence of glomerular disease
Pathogenesis Renal Tubular injury
-
Impaired renal blood flow
(shock)
-Tubular
necrosis
caused by toxic drugs or chemicals (damage epithelium - eventually regenerates)
Clinical Manifestation Tubular injury
-
Acute renal failure
: oliguria, anuria
-Tubular function slowly restored by regeneration of damaged epithelium
-
Treated by dialysis until function returns
Oliguria
producing small amounts of urine
Anuria
failure to produce urine at all
Cysts
fluid filled cavity surrounded by epithelium
Renal cysts: Solitary Cysts
-Common
-Not associated with impairment of renal function
Polycystic Kidney Disease
- A common hereditary autosomal dominant disease (need 1 gene)
-Disturbed
proliferation of tubular epithelial cells leads to formation of cysts that detach from tubules
-Cysts enlarge and destroy renal tissue and function
-Some form cysts in live or cereb
polycystic kidney disease treatment
no specific treatment until kidneys fail
age polycystic kidney disease
Onset of renal failure by late middle age
Renal Failure(Uremia)
inability of the kidneys to perform their normal regulatory and excretory functions
-Retention of excessive byproducts of protein metabolism in the blood
-ERSD = renal failure
Acute Renal Failure Cause
tubular necrosis
from
impaired blood flow
to kidneys or effects of
toxic drugs
- Renal function usually returns
Chronic Renal Failure
-From progressive, chronic kidney disease
- 40% from diabetic nephropathy
- 25% from nephrosclerosis due to hypertension
-Relatively normal function can be maintained until about 80% or renal failure has been lost
Renal Failure Diagnosis
Measure retention of waste products normally excreted by kidneys
- Blood urea nitrogen (BUN)
- Creatine
-Calculating creatine clearance (Vol. of blood that can be cleared of creatine in 1 minute)
Non-specific Symptoms of Renal Failure
o Weakness
o Loss of appetite
o Nausea
o Vomiting
Specific Symtpoms of Renal Failure
-
Anemia
(Kidneys secrete erythropoietin (EPO) - can't create new RBC's)
-Toxic manifestation from retained waste products
-
Edema
due to retention of salt and water
-
Hypertension
Treatment Renal Failure
-Dialysis
(Hemodialysis /Peritoneal dialysis)
-Treat anemia (Erythropoietin/ Iron)
- Treat electrolyte abnormalities
- Dietary restrictions
(Vit D supplementation)
-Renal transplantation
(Not widley available - several year wait)
Dialysis
- substitutes for the functions of the kidneys by removing waste products from patient's blood
(Excess electrolyte and fluid filtering)
- Waste products in patient's blood diffuse across a semipermeable membrane into a solution (dialysate) on the other si
Two types of Dialysis
- Hemodialysis
- Peritoneal dialysis
Hemodialysis
Patient's circulation connected to artificial kidney machine
-Must have adequate access to the circulation
(Creation of an arteriovenous fistula between radial artery and vein)
-Blood cleansed and excess fluid removed
-Treatments last from
3-4 hours three
Peritoneal Dialysis
Patient's own peritoneum
used as dialyzing membrane
- Indwelling tube placed in peritoneal cavity
-Dialysis fluid fills peritoneal cavity
-Allowed to equilibrate
-Drained
-Cycles repeated
Risks of Peritoneal Dialysis
Less efficient than hemodialysis
-Carries risk of peritonitis
-DO IT ON OWN AT HOME
- Not as effective in cleaning blood
Renal Transplant
Kidney is from a living donor or cadaver
-Survival of transplant depends on similarity of
HLA antigens between donor and recipient
(~ 10 years per transplant)
-Patient's immune system must be suppressed to prevent rejections of the kidney