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Chapte_19
Term | Definition |
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renal system | a bodily system responsible for clearing waste products from the blood while maintaining proper fluid and electrolyte balance; also called the urinary system |
kidneys | a pair of organs that filter blood for metabolic by-products and waste substances and also balance fluids and electrolytes in the body |
ureter | a duct that transports the waste products and excess fluid from the kidneys to the bladder |
urinary bladder | a sac located in the pelvic region that collects and holds urine until the fluid exits the body during urination |
urethra | a canal that discharges urine and in men, carries semen as well as urine |
adrenal glands | a pair of glands located on top of the kidneys |
renal artery | an artery that branches off from the abdominal aorta and brings blood into the kidneys |
renal vein | a vein that returns blood that has been filtered in the kidneys to the bloodstream |
renal cortex | the outer layer on the kidneys that is responsible for hormone production |
renal medulla | tissue found in middle, body of each kidney that is made up of many triangle-shaped sections that perform filtration |
nephron | the functional filtering unit of the kidney |
afferent arteriole | the entrance to the nephron where blood containing fluid and waste products enter |
Bowman’s capsule | a cup-shaped structure in the kidneys that filters fluid and waste products out of the blood by pressure |
glomerulus | a structure in the Bowman's capsule that consists of a capillary tightly folded |
glomerular filtration | the first step in urine production and the maintenance of fluid balance whereby large molecules are not filtered out, but most fluids and other smaller substances are |
efferent arteriole | an arteriole whereby blood leaves the Bowman’s capsule and renters the circulation |
filtrate | fluids and by-products filtered out of the blood in the glomerulus that continue on through the nephron |
loop of Henle | a part of the nephron where molecules selectively reenter the bloodstream via several mechanisms |
filtration | the process of substances moving across the membranes due to the force of pressure |
reabsorption | the process of absorbing substances from the nephron back into the bloodstream |
secretion | the process of elaborating or releasing a product |
anuria | the inability to produce urine |
aldosterone | a hormone that regulates the rate and volume of urine production |
antidiuretic hormone (ADH) | a hormone that regulates the rate and volume of urine production |
internal urinary sphincter | an involuntary muscle that keeps urine from flowing back into the ureters once it enters the bladder |
external urinary sphincter | a voluntary muscle that holds urine in the bladder before it exits the body |
detrusor muscle | a muscle in the bladder that contracts and pushes out urine |
micturition | the process of urination |
urinary retention | a condition that occurs when the kidneys make urine but the micturition process does not function properly and, consequently, urine accumulates in the bladder |
incontinence | the inability to control the external urinary sphincter, thus allowing urine to leak out of the bladder |
nephrotoxicity | direct damage to kidney tissue as a result of exposure to drugs or other chemicals |
urinary tract infection (UTI) | an infection that usually occurs in the bladder but can affect any part of the urinary system |
cystitis | a lower urinary tract infection involving the bladder |
pyelonephritis | an upper urinary tract infection affecting the kidneys |
prostatitis | a prostate infection in men |
spastic bladder | a malfunction of the detrusor muscles in the bladder, causing contraction and frequent urination |
antispasmodics | a drug class used to treat spastic bladder and urinary frequency that works by inhibiting acetylcholine in the autonomic nerves that control involuntary bladder contraction and emptying |
benign prostatic hyperplasia (BPH) | a chronic condition that happens in men as the prostate gland enlarges with age |
prostate-specific antigen (PSA) | a laboratory test that can screen for benign prostatic hyperplasia and more serious prostate problems |
alpha blockers | a class of drugs that is used for patients with benign prostatic hyperplasia that work by inhibiting the alpha-1 receptors that relax smooth muscle in the prostate and bladder |
5-alpha reductase inhibitors | a drug class used for benign prostatic hyperplasia and male-pattern hair loss that work by inhibiting the conversion of testosterone into dihydrotestosterone (DHT) |
acute renal failure | a condition that occurs as a result of some type of damage, either physical or chemical, or lack of blood supply to the kidneys; results in altered urine production and filtering function; reversible in many cases |
chronic kidney disease (CKD) | a condition that involves progressive damage or results in the death of kidney tissue over time; eventually may require kidney transplant; not reversible |
blood urea nitrogen (BUN) | a laboratory test used to monitor the concentration of urea and nitrogen in the blood; indicator of kidney function |
serum creatinine (SCr) | a laboratory test used to monitor the concentration of creatinine in the blood; marker for kidney function |
creatinine clearance (CrCl) | a calculation that estimates f kidney function while taking into account such factors as age and gender |
glomerular filtration rate (GFR) | a calculation that estimates kidney function while taking into account such factors as age and gender |
Cockcroft and Gault equation | the most common formula to calculate creatinine clearance |
dialysis | an artificial method of filtering blood and correcting the electrolyte imbalances caused by renal failure |
hemodialysis | a method of dialysis that is accomplished by diverting blood flow through a machine that mechanically filters the blood and returns the blood to the body |
peritoneal dialysis | a method of dialysis that is accomplished by putting dialysate (a special fluid that draws toxins from the body into itself) into the abdominal cavity and leaving it there for a period of time then removing it |
diuretics | a drug class used either to improve urine output in renal failure or to reduce blood volume in high blood pressure |
thiazide diuretics | a drug class used to treat hypertension and works by inhibiting reabsorption of sodium and chloride ions in the distal tubule of the nephron |
loop diuretics | a drug class used to treat renal failure and works by inhibiting reabsorption of sodium, chloride, and water in the ascending loop of Henle |
potassium-sparing diuretics | a drug class used to treat hypertension and works by blocking the exchange of potassium for sodium that takes place in the distal tubule |
aldosterone antagonists | a drug class used to treat hypertension and hyperaldosteronism (the overproduction of aldosterone) and works by inhibiting a hormone that promotes fluid retention |
carbonic anhydrase inhibitors | a drug class used to treat open-angle glaucoma and diuresis in congestive heart failure; works in the nephron by increasing excretion of bicarbonate ions, which carry sodium, potassium, and water into the urine |
potassium supplement | an agent that replenishes potassium levels in the body |
osmotic diuretics | a class of drugs used to treat severe trauma, cardiac operations, and elevated intracranial pressure; works by increasing the concentration of the filtrate which hinders reabsorption of water into the bloodstream from the renal tubules |
saw palmetto | an herbal treatment used to treat benign prostatic hyperplasia symptoms, such as frequent or painful urination, as well as urination hesitancy and urgency |
cranberry juice | a beverage used for prevention of recurrent urinary tract infections |