Chapter 7: Urinary System

nitrogenous wastes

• urea

• creatinine

• uric acid

metabolic waste products filtered from bloodstream by kidney

creatinine

byproduct of muscle energy metabolism (creatine breakdown); nitrogenous waste execreted in urine

urea

created bye liver as byproduct of protein metabolism

uric acid

waste product formed from breakdown of purines, found in Cody’s cells and in certain foods

functions of kidney

• filter nitrogenous wastes to form urine; about 200 quarts of blood are filtered every day to form 2 quarts of urine

• maintain proper balance of water, electrolytes (sodium, potassium), and acids

• release hormones: renin, erythroprotein(EPO), calciferol

• degrade and eliminate hormones from the bloodstream

renin

enzyme important in adjusting blood pressure

erythropoietin (EPO)

hormone that stimulates RBC production in bone marrow; secreted by kidney

calciferol

active form of vitamin D necessary for the absorption of calcium from the intestine

organs of male urinary system

• kidney

• ureter

• urinary bladder

• urethra

organs of female urinary system

• kidney

• ureter

• urinary bladder

• urethra

voiding

urination

how kidneys produce urine

• blood enters the kidneys through the right and left renal arteries

• arteries carry blood to the capillaries

• glomeruli filter the blood

glomerulus and glomerular/Bowman capsule

• blood passes through the glomeruli

• glomerular (Bowman) capsule surrounds each glomerulus

• renal tube is attached to each Bowman capsule

3 steps in formation of urine

• glomerular filtration (water, sugar, wastes, salts)

• tubular reabsorption (water, sugar, sodium)

• tubular secretion (acids, potassium, drugs)

the glomerulus and a renal tubule combine o form a unit called a

nephron

approx. how many nephrons are in a kidney

1,000,000

all collecting tubules lead to the

renal pelvis

calyces or calices

small, cuplike regions of renal pelvis; the term comes from the Greek, kalux, meaning a cup or case surrounding a flower bud

functions of the kidneys

• remove nitrogenous wastes

• balance water and electrolytes

• release hormones

• degrade and eliminate hormones

arteriole

small artery

catheter

tube for injecting or removing fluids

cortex

outer region of an organ

electrolyte

chemical element that carries an electrical charge when dissolved in water

-poietin

substance that forms

filtration

process whereby some substances pass through a filter

glomerular capsule

enclosing structure surrounding each glomerulus; also called Bowman capsule

glomerulus

tiny ball of capillaries in the kidney

hilum

depression in the part of an organ where blood vessels and nerves enter an leave; comes from Latin meaning a small thing

kidney

one of two bean-shaped organs that filter nitrogenous waste from the bloodstream to form urine

meatus

opening or canal

medulla

inner region of an organ; the term comes from the Latin, medulla, meaning marrow

nephron

functional unit of kidney where filtration, reabsorption, and secretion take place

nitrogenous waste

substance containing nitrogen and excreted in urine, ex. urea, uric acid, creatinine

potassium (K+)

an electrolyte regulated by the kidney

reabsorption

renal tubules return material necessary to the body back into the bloodstream

renal artery

blood vessel that carries blood to the kidney

renal pelvis

central collection region in the kidney

renal tubules

microscopic tubes in the kidney where urine is formed after filtration

renal vein

blood vessel that carries blood away from the kidney

renin

enzyme secreted by the kidney that raised bp

sodium (Na+)

electrolyte regulated in the blood and urine by the kidneys; a common form of sodium is sodium chloride (salt)

trigone

triangular area in the urinary bladder

urea

major nitrogenous waste excreted in urine

ureter

one of two tubes leading from the kidneys to the urinary bladder

urethra

tube leading from the urinary bladder to the outside of the body

uric acid

nitrogenous waste product excreted in the urine

urinary bladder

hollow, muscular sac that holds and stores urine

urination (voiding)

process of expelling urine; aka micturition

cali/o, calic/o

calyx (calix); cup shaped

cyst/o

urinary bladder

glomerul/o

glomerulus

meat/o

meatus

nephr/o

kidney

pyel/o

renal pelvis

ren/o

kidney

trigon/o

trigone

ureter/o

ureter

urethr/o

urethra

vesic/o

urinary bladder

albumin/o

albumin

azot/o

nitrogen

bacteri/o

bacteria

dips/o

thrist

kal/o

potassium

ket/o, keton/o

ketone bodies

litho/o

stone

natr/o

sodium

noct/o

night

olig/o

scanty

-poietin

substance that forms

py/o

pus

-tripsy

to crush

ur/o

urea

-uria

urination; urine condition

urin/o

urine

tests in urinalysis

• color

• appearance

• pH

• protein

• glucose

• specific gravity

• ketone bodies

• sediment

• phenylketonuria

• bilirubin

in urinalysis, what does test of specific gravity reflect

amount of wastes, minerals, and solids in the urine

glomerulonephritis

inflammation of the glomeruli, the tiny filtering units of kidneys; it can reduce the kidneys’ ability to filter blood properly

interstitial nephritis

inflammation of the kidney’s interstitial tissue (tissue surrounding the nephrons), often caused by medications, infections, or autoimmune diseases

nephrolithiasis

formation or presence of kidney stones in kidneys

nephrotic syndrome

kidney disorder in which the kidneys leak large amounts of protein into urine, causing swelling (edema), low blood protein, and high cholesterol

polycystic kidney disease (PKD)

kidneys contain masses of cysts; typically polycystic kidneys weigh 20 times more than their usual weight

pyelonephritis

inflammation or infection of the kidney and renal pelvis, usually caused by a bacterial urinary tract infection (UTI) that spreads to the kidney

renal cell carcinoma

most common type of kidney cancer in adults, begins in the cells lining the kidney tubules

renal failure

condition in which kidneys lose their ability to filter wastes and excess fluid from the blood, may be acute (sudden) or chronic (long term)

renal hypertension

high blood pressure caused by kidney disease or narrowing of the arteries supplying the kidneys (renal artery stenosis)

Wilms tumor

a malignant kidney tumor that occurs primarily in young children (also called nephroblastoma)

bladder cancer

malignant tumor that develops in the tissues of the urinary bladder, most commonly in the bladder lining (urothelium)

diabetes insipidus (DI)

disorder in which the body cannot properly regulate water balance, causing large amounts of dilute urine and excessive thirst; its is usually due to lack of antidiuretic hormone (ADH) or the kidneys not responding to ADH

diabetes mellitus (DM)

disorder in which the body cannot properly regulate blood glucose (sugar) because of problems with insulin production or insulin action, resulting in high blood sugar

frequent voluntary urination at night

nocturia

blood urea nitrogen (BUN)

a blood test that measures the amount of urea nitrogen in the blood; it helps evaluate kidney function because healthy kidneys remove urea from the bloodstream

creatinine clearance test

test that measures how efficiently the kidneys filter creatinine from the blood; estimate the glomerular filtration rate (GFR), which reflects kidney function

CT urography x-ray

CT scan of urinary tract that uses contrast dye to produce detailed images of the kidneys, ureters, and bladder; helps detect kidney stones, tumors, blockages, and other urinary tract abnormalities

kidneys, ureters, and bladder (KUB) x-ray

plain x-ray of the kidneys, ureters and bladder; commonly used to detect kidney stones, bowel obstruction, or abnormal calcifications

renal angiography x-ray

x-ray study in which contrast dye is injected into the renal arteries to visualize the blood vessels of the kidneys; helps diagnose narrowed arteries, aneurysms, or other vascular problems

retrograde pyelogram (RP) x-ray

x-ray procedure in which contrast dye is injected through the urethra and bladder into the ureters and renal pelvis to visualize the urinary tract; used to detect blockages, stones, or tumors

voiding cystourethrogram (VCUG) x-ray

x-ray study of the bladder and urethra performed while the patient urinates (voids); contrast dye is placed into the bladder through a catheter to detect vesicoureteral reflux (backward flow of urine) or structural abnormalities

CT computed tomorgrpahy

scan with contrast shows a benign cyst on the kidney

ultrasonography

imaging urinary tract structures using high frequency sound waves