The Renal System Flashcards
Urinary System
Regulates: -Fluid volume -Blood pressure -Metabolic waste and drug excretion -Vitamin D conversion -Acid-base balance -Hormone synthesis Includes: kidneys, ureters, bladder, and urethra
Renal capsule
connective tissue surrounding the kidney
Renal cortex
area immediately beneath the capsule, which contains the nephrons.
Renal artery
supplies each kidney with blood
Renal hilum
opening in the kidney the renal artery and nerves enter and the renal vein and ureter exit
Renal sinus
cavity form the renal pelvis
Calyces
tubes through which urine drains into the renal pelvis
Ureters
transports urine from the calyces to the bladder
Bladder
muscular structure that serves as a reservoir for urine until it can be excreted
Urethra
transports urine from bladder to urinary meatus
Urination
Voluntary activity
As urine volume in the bladder increases, the urine exerts pressure on the two bladder sphincters (internal and external) and stretch receptors in the bladder
Normal daily urine output is 1,500 mL
Three Components of Urine Formation
Filtration
Reabsorption
Secretion
Bowman’s capsule
double membrane that surrounds the glomerulus
Glomerulus
cluster of capillaries
where filtration happens
Glomerular filtration rate
rate of blood flow through the glomerulus
Best indicator renal function
Normal 125 mL/min
Juxtaglomerular cells
measure blood flow in the afferent arteriole and urine flow and composition
Renin
comes from the kidneys;
which turns on the Na+/K+ ATPase in the distal tubule
K+
is secreted
Na+ and water
are reabsorbed
Hormonal Influences
Antidiuretic hormone
Aldosterone
Renin-angiotensin-aldosterone
Other Renal Activities
Converts vitamin D to its active form
Secretes bicarbonate
Excretes or retains hydrogen
Synthesizes atrial natriuretic peptide, erythropoietin, and renin
A man has severe renal disease
Why does he develop
Anemia?
Weak bones?
He’s not making enough red blood cells. Kidney is not responding when the body ask for blood.
weak bones- lack of vitamin D
Tests of Renal Function
Blood Test
Creatinine
BUN (Blood Urea Nitrogen)
Creatinine Clearance
Urinalysis (UA)
Urine Sediment
Glomerular Filtration Rate
We expect a 10:1 ratio between BUN and Creatinine
If both are elevated, it indicates kidney damage
If only BUN is elevated, it indicates dehydration
WHY?
Cause the water balances the concentration of the blood
Health care providers frequently ask a patient for a clean- catch, midstream urine sample. Why?
best sample possible
pee a little cause they want wants in the bladder.
results could be inaccurate with stuff on the skin
Changes with Aging
Exacerbated by the presence of chronic conditions
Increased risk for waste accumulation and loss of homeostatic regulation
Other renal-related complications include anemia, hypertension, and osteoporosis
Also at increased risk for drug toxicity
Polycystic Kidney Disease
Inherited disorder characterized by numerous, grape-like clusters of fluid-filled cysts in both kidneys
Cysts enlarge the kidneys while compressing and eventually replacing the functional kidney tissue
Polycystic Kidney Disease Manifestations
Symptoms that may both children and adults:
Hematuria
Nocturia
Drowsiness
Symptoms in adults include: Hypertension Lumbar pain Increased abdominal girth Swollen, tender abdomen Grossly enlarged, palpable kidneys
Cystic disease of the kidney
Simple and acquired renal cysts
Medullary cystic disease
Autosomal dominant polycystic kidney disease
Glomerulonephritis
Bilateral inflammatory disorder of the glomeruli that typically follows a streptococcal infection
Diagnosis: history, physical examination, urinalysis, blood chemistry, serum antibody levels, computed tomography, and renal biopsy
Treatment: antibiotic therapy, corticosteroids, blood pressure management, and temporary dialysis
Glomerulonephritis Signs and Symptoms:
- Hematuria (blood in urine), proteinuria (protein in urine)
- Edema
- Malaise, headache, N/V
- Elevated B/P and fluid volume overload
- Dark urine with blood (cola colored)
- Anemia
- Dyspnea, cardiomegaly, pulmonary edema
- Oliguria (scant urine output)
- Confusion
Why?
- Damage to the membrane allowing protein to leak
- Proper excretion is not occurring
- Retaining toxins
- Fluid retention d/t decreased urine output (UOP)
- RBCs and protein in the urine
- No erythropoietin
- Circulatory overload
- Unable to Excrete
- Sodium imbalances and overload
Nephritic syndrome
Inflammatory injury to the glomeruli that can occur because of antibodies interacting with normally occurring antigens in the glomeruli- triggers complement system
Causes: diseases that initiate the inflammatory response
Manifestations: gross hematuria, urinary casts and leukocytes, low GFR, azotemia (high BUN and creatinine), oliguria, and high blood pressure
Complications: impaired renal function
Pyelonephritis
Infection that has reached one or both kidneys
E. coli is the most common culprit
Kidneys become grossly edematous and fill with exudate, compressing the renal artery
Abscesses and necrosis can develop, impairing renal function and causing permanent damage
May be acute or chronic
Complications: renal failure, recurrent UTIs, and sepsis
Pyelonephritis manifestations
Manifestations: severe UTI symptoms, flank pain, and increased blood pressure
Diagnosis: history, physical examination, urinalysis, urine and blood cultures, complete blood count, cystoscopy, intravenous pyelogram, computed tomography, renal ultrasound, biopsy, and cystourethrogram
Treatment: usual UTI treatments, but long-term antibiotics (4–6 weeks) are usually required
Pyelonephritis-
Signs and Symptoms
Chills and fever Anorexia, N,V Dysuria, frequency, urgency Pyuria (pus) in the urine CVA tenderness
Why?
Infection
Kidneys cannot excrete toxins and they build up
Inflammation and infection of the kidneys
Bacterial growth
Infection of the kidneys
Consequences of Dilatation of Renal Tubules or Tract
Expansion of the kidney with urine (hydronephrosis)
Increased pressure inside the renal capsule
Compartment syndrome compresses blood vessels inside kidney
Renal ischemia
Stasis of urine
Risk of infection
Stones
Hydronephrosis
Abnormal dilation of the renal pelvis and the calyces of one or both kidneys
Causes: urolithiasis, tumors, benign prostatic hyperplasia, strictures, stenosis, and congenital urologic defects
Urolithiasis (Kidney Stones)
Presence of renal calculi, hard crystals composed of minerals that the kidneys normally excrete
More common in men and Caucasians
The most frequent type of calculi contains calcium in combination with either oxalate or phosphate
Other types include struvite or infection stones, uric acid stones, and cystine stones
Urolithiasis risk factors
pH changes urinary stasis family history obesity hypertension diet
Urolithiasis Manifestations:
Flank area pain Groin or leg pain Bloody, cloudy, or foul- smelling urine Dysuria Frequency Nausea, vomiting Fever and chills
Urinary Tract Obstructions
Signs and Symptoms
- Flank pain
- Urgency, frequency, hematuriaSigns and Symptoms
- N/V, Abd. Pain, diarrhea
- Fever and Chills
Why?
- Stone is obstructing the ureter, pelvis or tubes
- Stone passage causes spasms
- Severe pain, infection, nerve stimulation causing nausea
- Immune response to infection
Renal Cell Carcinoma
Manifestations: asymptomatic, painless hematuria, abnormal urine color, dull and achy flank pain, urinary retention, palpable mass over affected kidney, unexplained weight loss, anemia, polycythemia, hypertension, paraneoplastic syndromes, and fever
Renal Failure
Kidneys are unable to function adequately
Classified as either acute or chronic
Acute Kidney Injury
Sudden loss of renal function
Generally reversible
Most common in critically ill, hospitalized patients
Risk factors: advanced age, autoimmune disorders, and liver disease
There is a hope that the kidney will recover
Causes of Acute Kidney Injury
Prerenal conditions
Extremely low blood pressure or blood volume
Heart dysfunction
Intrarenal conditions Reduced blood supply within the kidneys Hemolytic uremic syndrome Renal inflammation Toxic injury
Postrenal conditions
Ureter obstruction
Bladder obstruction and dysfunction
Phases of Acute Kidney Injury
- Asymptomatic phase
- Oliguric phase - daily urine output decreases to approximately 400 mL or less, and waste products accumulate
- Diuretic phase - daily urine output increases to as much as 5 L
- Recovery phase - glomerular function gradually returns to normal
Manifestations of Acute Kidney Injury
Oliguric phase: decreasing urine output, electrolyte disturbances, fluid volume excess, azotemia, and metabolic acidosis
Diuretic phase: increased urine output, electrolyte disturbances, dehydration, and hypotension
Recovery phase: symptoms begin resolving
Acute Kidney Injury Diagnosis
Diagnosis: history, physical examination, blood chemistry, arterial blood gases, urinalysis, complete blood count, renal ultrasound, and biopsy
Acute Kidney Injury Treatment
Correct fluid and electrolyte imbalances
Dialysis
A diet high in calories and restricted in protein, sodium, potassium, and phosphates
Hypertension management
Anemia treatment with synthetic erythropoietin
Infection prevention strategies
there is a hope that
Chronic Kidney Disease
Gradual loss of renal function that is irreversible
Causes: diabetes mellitus, hypertension, urine obstructions, renal diseases, renal artery stenosis, ongoing exposure to toxins and nephrotoxic medications, sickle cell disease, systemic lupus erythematosus, smoking, advancing age
Phases of
Chronic Kidney Disease
Manifestations appear slowly
Stage 3-4: waste products begin to accumulate and kidneys don’t concentrate urine, maintain BP, or secrete erythropoietin
Stage 5: unable to maintain homeostasis while waste products, fluid, and electrolytes accumulate
Manifestations of Chronic Kidney Disease
Peripheral neuropathy, restless leg syndrome, and seizures Nausea and vomiting Anorexia Malaise Fatigue and weakness Headaches that seem unrelated to any other cause Decreased mental alertness Flank pain Jaundice Persistent pruritus Recurrent infections Sleep disturbances Hypertension Polyuria with pale urine (early) Oliguria or anuria with darkly colored urine (late) Anemia Bruising and bleeding tendencies Electrolyte imbalances Muscle twitches and cramps Pericarditis, pericardial effusion, pleuritis, and pleural effusion Congestive heart failure Respiratory distress and abnormal breath sounds Sudden weight change Edema of the feet and ankles Azotemia
Chronic Kidney Disease Diagnosis
Diagnosis: history, physical examination, urinalysis, blood chemistry, computed tomography, magnetic resonance imaging, renal ultrasound, biopsy, complete blood count, and arterial blood gases
Treatment:
Manage and prevent complications and alternative medication dosing (BP control, blood glucose control)
Smoking cessation
Dietary management depending on stage of disease (limit high phosphate foods, monitor proteins, potassium-rich foods, possible sodium and water restrictions)
Medications to manage complications
Dialysis or transplant for late stages
