Exam 6 Study Guide
Ch. 47 Kidney & Urinary Function
Aldosterone → hormone synthesized & released by the adrenal cortex ; Causes Kidneys to
reabsorb sodium
Antidiuretic Hormone (ADH) → hormone secreted by the posterior Pituitary; Causes Kidney
to reabsorb more water
Erythropoietin → glycoprotein produced by kidney; Stimulates bone marrow to produce RBCs
Anuria → decreased urine output of less than 50mL in 24 hr
Dysuria → painful or difficult urination
Oliguria → urine output less than 400mL in 24 hrs or less than 0.5mL/kg/hr over 6 hrs
Pyuria → WBCs in the urine
Renal Clearance → ability of the kidneys to clear solutes from the plasma
Urinary Casts → proteins secreted by damaged kidney tubules
Renal System
Functions :
- Regulates: electrolytes, acid-base balance, & RBC production
- Control : BP & water balance - Secretion: excrete wastes
- Renal clearance - Synthesis of Vit D to active form
- Filtration: Blood → Nephron - Reabsorption: body takes back needed
substances
Structures : - Kidneys → Ureters → Bladder → Urethra → toilet
- Each Kidney has 1 mill nephrons w/in the renal parenchyma
● Nephrons are responsible for formation of the filtrate that becomes urine
** Nephrons are the functional unit of Renal System **
Glomerular Filtration
Glomerulus → a tuft of capillaries forming part of the nephron where filtration occurs
GFR → Glomerular Filtration Rate : amount of plasma filtered through glomeruli in specific
amount of time
Normal GFR = 90 + mL/min (best indicator of Kidney Fx)
GFR < 60 = chronic kidney disease
GFR < 15 = Kidney failure
, - Many factors alter blood flow & pressure through Glomerulus including : ↓ BP, ↓
oncotic pressure in blood, and ↑ pressure in renal tubules from an obstruction
Nursing Assessment of Urinary System
Health History – what to ask about
- Burning urination (dysuria) - Blood in urine (Hematuria)
- Frequency, urgency, nocturia - Hx of HTN, DM, stones, or recurrent UTIs
- Med use: NSAIDs, ACE inhibitors, ATBs
Physical Assessment
- Inspect : edema, skin tiger, bruising, abdominal distention
- Auscultate : renal artery bruits → may indicate stenosis
- Palpate / Percuss : costovertebral angle (CVA) tenderness = Kidney infection/
inflammation (Pyelonephritis )
Identify Possible Etiology from Pain
Kidney (CVA tenderness) → acute obstruction, stones, blood clots, infection, or
trauma
Bladder (suprapubic pain) → overdistended bladder, infection, cystitis, or tumor
Ureter pain → stone, edema, or blood clot
Prostatic pain → prostate CA, or BPH
Urethral pain → Irritation of bladder neck, infection (UTI), trauma, or foreign body
Lab Studies
BUN = 8 - 20mg/dL Serves as index of renal fx ; Values are affected by protein intake, tissue
breakdown, & fluid vol change
- Elevated in dehydration or kidney dysfunction
Creatinine = Males: 0.6 - 1.2 Females: 0.4 - 1.0 Measures how much Cr (waste product) is
not being filtered by the Kidneys ….. HIGH Cr → Kidney fx is LOW
- BEST lab for Kidney fx
BUN : Creatinine Ratio = 10 : 1 Helps differentiate between dehydration & kidney injury
- Elevated ratio = hypovolemia
- Normal ratio but elevated BUN & Cr = kidney disease
** ↑ Cr is ALWAYS more concerning than ↑ BUN **
Urinalysis = look for protein, glucose, ketones, nitrites, RBCs, & WBCs
Ch. 47 Kidney & Urinary Function
Aldosterone → hormone synthesized & released by the adrenal cortex ; Causes Kidneys to
reabsorb sodium
Antidiuretic Hormone (ADH) → hormone secreted by the posterior Pituitary; Causes Kidney
to reabsorb more water
Erythropoietin → glycoprotein produced by kidney; Stimulates bone marrow to produce RBCs
Anuria → decreased urine output of less than 50mL in 24 hr
Dysuria → painful or difficult urination
Oliguria → urine output less than 400mL in 24 hrs or less than 0.5mL/kg/hr over 6 hrs
Pyuria → WBCs in the urine
Renal Clearance → ability of the kidneys to clear solutes from the plasma
Urinary Casts → proteins secreted by damaged kidney tubules
Renal System
Functions :
- Regulates: electrolytes, acid-base balance, & RBC production
- Control : BP & water balance - Secretion: excrete wastes
- Renal clearance - Synthesis of Vit D to active form
- Filtration: Blood → Nephron - Reabsorption: body takes back needed
substances
Structures : - Kidneys → Ureters → Bladder → Urethra → toilet
- Each Kidney has 1 mill nephrons w/in the renal parenchyma
● Nephrons are responsible for formation of the filtrate that becomes urine
** Nephrons are the functional unit of Renal System **
Glomerular Filtration
Glomerulus → a tuft of capillaries forming part of the nephron where filtration occurs
GFR → Glomerular Filtration Rate : amount of plasma filtered through glomeruli in specific
amount of time
Normal GFR = 90 + mL/min (best indicator of Kidney Fx)
GFR < 60 = chronic kidney disease
GFR < 15 = Kidney failure
, - Many factors alter blood flow & pressure through Glomerulus including : ↓ BP, ↓
oncotic pressure in blood, and ↑ pressure in renal tubules from an obstruction
Nursing Assessment of Urinary System
Health History – what to ask about
- Burning urination (dysuria) - Blood in urine (Hematuria)
- Frequency, urgency, nocturia - Hx of HTN, DM, stones, or recurrent UTIs
- Med use: NSAIDs, ACE inhibitors, ATBs
Physical Assessment
- Inspect : edema, skin tiger, bruising, abdominal distention
- Auscultate : renal artery bruits → may indicate stenosis
- Palpate / Percuss : costovertebral angle (CVA) tenderness = Kidney infection/
inflammation (Pyelonephritis )
Identify Possible Etiology from Pain
Kidney (CVA tenderness) → acute obstruction, stones, blood clots, infection, or
trauma
Bladder (suprapubic pain) → overdistended bladder, infection, cystitis, or tumor
Ureter pain → stone, edema, or blood clot
Prostatic pain → prostate CA, or BPH
Urethral pain → Irritation of bladder neck, infection (UTI), trauma, or foreign body
Lab Studies
BUN = 8 - 20mg/dL Serves as index of renal fx ; Values are affected by protein intake, tissue
breakdown, & fluid vol change
- Elevated in dehydration or kidney dysfunction
Creatinine = Males: 0.6 - 1.2 Females: 0.4 - 1.0 Measures how much Cr (waste product) is
not being filtered by the Kidneys ….. HIGH Cr → Kidney fx is LOW
- BEST lab for Kidney fx
BUN : Creatinine Ratio = 10 : 1 Helps differentiate between dehydration & kidney injury
- Elevated ratio = hypovolemia
- Normal ratio but elevated BUN & Cr = kidney disease
** ↑ Cr is ALWAYS more concerning than ↑ BUN **
Urinalysis = look for protein, glucose, ketones, nitrites, RBCs, & WBCs
