Term
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Definition
| principal means of waste removal |
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Term
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Definition
•filters blood plasma, separates waste from useful chemicals, returns useful substances to blood, eliminates wastes
•regulate blood volume and pressure by eliminating or conserving water
•regulate the osmolarity of the body fluids by controlling the relative amounts of water and solutes eliminated
•secretes enzyme, renin
•secretes the hormone, erythropoietin
•collaborate with the lungs to regulate the PCO2 and acid-base balance of body fluids
•final step in synthesizing hormone, calcitriol
•gluconeogenesis from amino acids in extreme starvation |
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Term
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Definition
| activates hormonal mechanisms that control blood pressure and electrolyte balance |
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Term
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Definition
| stimulates the production of red blood cells |
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Term
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Definition
| contributes to calcium homeostasis |
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Term
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Definition
| any substance that is useless to the body or present in excess of the body's needs |
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Term
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Definition
| waste substance produced by the body |
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Term
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Definition
| proteins -> amino acids -> NH2 removed -> forms ammonia, liver converts to urea |
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Term
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Definition
| –product of nucleic acid catabolism |
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Term
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Definition
| –product of creatine phosphate catabolism |
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Term
| blood urea nitrogen (BUN) |
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Definition
| expression of the level of nitrogenous waste in the blood |
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Term
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Definition
–elevated BUN
-indicates renal insufficiency |
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Term
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Definition
–syndrome of diarrhea, vomiting, dyspnea, and cardiac arrhythmia stemming from the toxicity of nitrogenous waste
-treatment: hemodialysis or organ transplant |
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Term
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Definition
| separation of wastes from body fluids and eliminating them |
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Term
| the four body systems carry out excretion |
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Definition
–respiratory system
•CO2, small amounts of other gases, and water
–integumentary system
•water, inorganic salts, lactic acid, urea in sweat
–digestive system
•water, salts, CO2, lipids, bile pigments, cholesterol, other metabolic waste, and food residue
–urinary system
•many metabolic wastes, toxins, drugs, hormones, salts, H+ and water |
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Term
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Definition
| empties into inferior vena cava |
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Term
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Definition
•each kidney has about 1.2 million
•each composed of two principal parts:
–renal corpuscle
–renal tubule |
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Term
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Definition
–filters the blood plasma
-consists of the glomerulus and a two-layered glomerular (Bowman) capsule that encloses glomerulus |
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Term
| parietal (outer) layer of Bowman capsule |
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Definition
| is composed of simple squamous epithelium |
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Term
| visceral (inner) layer of Bowman capsule |
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Definition
| consists of elaborate cells called podocytes that wrap around the capillaries of the glomerulus |
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Term
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Definition
| separates the two layers of Bowman capsule |
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Term
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Definition
| the side of the corpuscle where the afferent arterial enter the corpuscle and the efferent arteriole leaves |
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Term
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Definition
| the opposite side of the corpuscle where the renal tubule begins |
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Term
| proximal convoluted tubule (PCT) |
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Definition
–arises from glomerular capsule
–longest and most coiled region
–simple cuboidal epithelium with prominent microvilli for majority of absorption
-reabsorbs 65% of glomerular filtrate and returns it to peritubular capillaries |
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Term
| nephron loop (loop of Henle) |
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Definition
–long U-shaped portion of renal tubule
–descending limb and ascending limb
–thick segments have simple cuboidal epithelium
•heavily engaged in the active transport of salts and have many mitochondria
–thin segment has simple squamous epithelium
•cells very permeable to water
-reabsorbs another 25% of filtrate |
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Term
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Definition
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Term
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Definition
–15% of all nephrons
–very long nephron loops, maintain salinity gradient in the medulla and helps conserve water |
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Term
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Definition
–nerves and ganglia wrapped around each renal artery
–carries sympathetic innervation from the abdominal aortic plexus
–carries parasympathetic innervation from the vagus nerve –increases rate of urine production |
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Term
| The three stages in which kidneys convert blood plasma to urine |
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Definition
–glomerular filtration
–tubular reabsorption and secretion
–water conservation |
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Term
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Definition
–the fluid in the capsular space
–similar to blood plasma except that is has almost no protein |
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Term
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Definition
–three barriers through which fluid passes
–fenestrated endothelium of glomerular capillaries
–basement membrane
–filtration slits |
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Term
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Definition
| a special case of the capillary fluid exchange process in which water and some solutes in the blood plasma pass from the capillaries of the glomerulus into the capsular space of the nephron |
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Term
| fenestrated endothelium of glomerular capillaries |
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Definition
•70-90 nm filtration pores exclude blood cells
•highly permeable |
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Term
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Definition
•proteoglycan gel, negative charge, excludes molecules greater than 8nm
•albumin repelled by negative charge
•blood plasma is 7% protein, the filtrate is only 0.03% protein |
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Term
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Definition
•podocyte cell extensions (pedicels) wrap around the capillaries to form a barrier layer with 30 nm filtration slits
•negatively charged which is an additional obstacle for large anions |
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Term
| kidney infections and trauma |
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Definition
| can damage the filtration membrane and allow albumin or blood cells to filter |
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Term
| proteinuria (albuminuria) |
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Definition
| presence of protein in the urine |
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Term
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Definition
| presence of blood in the urine |
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Term
| glomerular filtration rate (GFR) |
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Definition
–the amount of filtrate formed per minute by the 2 kidneys combined
-total amount of filtrate produced equals 50 to 60 times the amount of blood in the body
–99% of filtrate is reabsorbed since only 1 to 2 liters urine excreted per day |
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Term
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Definition
–fluid flows through the renal tubules too rapidly for them to reabsorb the usual amount of water and solutes
–urine output rises
–chance of dehydration and electrolyte depletion |
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Term
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Definition
–wastes reabsorbed
–azotemia may occur |
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Term
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Definition
| the ability of the nephrons to adjust their own blood flow and GFR without external (nervous or hormonal) control |
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Term
| Effectiveness of Autoregulation |
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Definition
-maintains a dynamic equilibrium -GFR fluctuates within narrow limits only
–blood pressure changes do affect GFR and urine output somewhat |
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Term
| Sympathetic Control of GFR |
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Definition
| •sympathetic nervous system and adrenal epinephrine constrict the afferent arterioles in strenuous exercise or acute conditions like circulatory shock |
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Term
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Definition
•kidneys reduce 180 L of glomerular filtrate to 1 or 2 liters of urine each day
•two-thirds of water in filtrate is reabsorbed by the PCT
•reabsorption of all the salt and organic solutes makes the tubule cells and tissue fluid hypertonic |
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Term
| Uptake by the Peritubular Capillaries |
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Definition
•after water and solutes leave the basal surface of the tubular epithelium, they are reabsorbed by the peritubular capillaries
–reabsorbed by osmosis and solvent drag |
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Term
| the three factors that promote osmosis into the capillaries |
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Definition
–accumulation of reabsorbed fluid around the basolateral sides of epithelial cell creates high interstitial fluid pressure that drives water into the capillaries
–narrowness of efferent arterioles lowers blood hydrostatic pressure in peritubular capillaries so there is less resistance to absorption
–proteins remain in blood after filtration, which elevates colloid osmotic pressure |
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Term
| Transport Maximum of Glucose |
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Definition
•each solute has its own transport maximum
–any blood glucose level above 220 mg/dL results in glycosuria |
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Term
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Definition
| process in which the renal tubule extracts chemicals from the capillary blood and secretes them into tubular fluid |
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Term
| the two purposes in proximal convoluted tubule and nephron loop |
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Definition
–waste removal
–acid-base balance |
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Term
| primary function of nephron loop |
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Definition
| to generate salinity gradient that enables collecting duct to concentrate the urine and conserve water |
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Term
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Definition
-reabsorb variable amounts of water salt and are regulated by several hormones
–aldosterone, atrial natriuretic peptide, ADH, and parathyroid hormone |
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Term
| the two kinds of cells in the DCT and collecting duct |
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Definition
–principal cells
–intercalated cells |
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Term
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Definition
•most numerous
•have receptors for hormones
•involved in salt and water balance |
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Term
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Definition
| •involved in acid/base balance by secreting H+ into tubule lumen and reabsorbing K+ |
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Term
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Definition
| the “salt-retaining” hormone |
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Term
| atrial natriuretic peptide (ANP) |
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Definition
| secreted by atrial myocardium of the heart in response to high blood pressure |
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Term
| antidiuretic hormone (ADH) |
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Definition
-secreted by posterior lobe of pituitary
–water in the tubular fluid reenters the tissue fluid and bloodstream rather than being lost in urine |
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Term
| parathyroid hormone (PTH) |
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Definition
| secreted from parathyroid glands in response to calcium deficiency (hypocalcemia) |
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Term
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Definition
| -completes the process of determining the chemical composition of urine |
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Term
| Urine Formation III: Water Conservation |
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Definition
| •the kidney eliminates metabolic wastes from the body, but also prevents excessive water loss as well |
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Term
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Definition
-lower end of CD permeable to urea
–urea contributes to the osmolarity of deep medullary tissue
–continually cycled from collecting duct to the nephron loop and back
–urea remains concentrated in the collecting duct and some of it always diffuses out into the medulla adding to osmolarity |
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Term
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Definition
| the examination of the physical and chemical properties of urine |
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Term
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Definition
-clear, almost colorless to deep amber -yellow color due to urochrome pigment from breakdown of hemoglobin (RBCs) –other colors from foods, drugs or diseases
–cloudiness or blood could suggest urinary tract infection, trauma or stones |
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Term
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Definition
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Term
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Definition
| blood in urine due to urinary tract infection, trauma, or kidney stones |
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Term
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Definition
| bacteria degrade urea to ammonia, some foods impart aroma |
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Term
| chemical composition of urine |
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Definition
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Term
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Definition
| urea, sodium chloride (NaCl), potassium chloride (KCl), creatinine, uric acid, phosphates, sulfates, traces of calcium, magnesium, and sometimes bicarbonate, urochrome and a trace of bilirubin |
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Term
| abnormal to find in urine |
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Definition
| glucose, free hemoglobin, albumin, ketones, bile pigments |
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Term
| normal urine volume for average adult |
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Definition
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Term
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Definition
| output in excess of 2 liters per day |
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Term
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Definition
| output of less than 500 milliliter per day |
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Term
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Definition
| 0 to 100 milliliters per day |
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Term
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Definition
| any metabolic disorder resulting in chronic polyuria |
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Term
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Definition
–any chemical that increases urine volume
-commonly used to treat hypertension and congestive heart failure by reducing the body's fluid volume and blood pressure |
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Term
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Definition
| smooth-surfaced triangular area marked with openings of ureters and urethra |
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Term
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Definition
-muscular sac located on floor of pelvic cavity
–inferior to peritoneum and posterior to pubic symphysis
–highly distensible |
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Term
| renal calculus (kidney stone) |
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Definition
| hard granule of calcium phosphate, calcium oxalate, uric acid, or a magnesium salt called struvite |
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Term
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Definition
–infection of the urinary bladder
–especially common in females due to short urethra
–frequently triggered by sexual intercourse
–can spread up the ureter causing pyelitis |
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Term
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Definition
| –infection of the renal pelvis |
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Term
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Definition
–infection that reaches the cortex and the nephrons
–can result from blood-borne bacteria |
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Term
| between acts of urination, the bladder is filling |
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Definition
–detrusor muscle relaxes
–urethral sphincters are tightly closed
–somatic motor fibers from upper sacral spinal cord through pudendal nerve to supply the external sphincter give us voluntary control |
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Term
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Definition
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Term
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Definition
| spinal reflex that partly controls urination |
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Term
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Definition
| a state in which the kidneys cannot maintain homeostasis due to extensive destruction of their nephrons |
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Term
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Definition
–procedure for artificially clearing wastes from the blood
–wastes leave bloodstream and enter the dialysis fluid as blood flows through a semipermeable cellophane tube; also removes excess body water |
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