Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
70 Cards in this Set
- Front
- Back
|
The urinary consists of 4 parts of the body. What are the 4 parts and what are each of their functions?
|
1. Kidneys - Form Urine
2. Ureters - Transport Urine 3. Urinary Bladder - Store Urine 4. Urethra - Carries Urine to Outside of Body |
|
|
What is the outer portion of the kidney called?
|
Renal Cortex
|
|
|
What is the inner portion of the kidney called?
|
Renal Medulla
|
|
|
What are the symptoms of acute renal failure?
|
A sudden loss of kidney function, usually associated with shock or intence renal vasoconstriction. It can last for several days to a long as weeks
|
|
|
What is cystitis?
|
Inflammation of the urinary bladder
|
|
|
What is hemoturia?
|
Blood in the urine
|
|
|
What is Hemodialysis?
|
It is a method of clearing waste products from the blood in which blood passes by the semipermeable membrance of the artificial kidney and waste products are removed by diffusion
|
|
|
What is nocturia?
|
"night urination" or during sleep
|
|
|
What is oliguria?
|
the condition of having urinary volumes of less than 500 ml/day
|
|
|
What is plyuria?
|
Excessive urine output
|
|
|
What is uremia?
|
The retention of urinary constituents in the blood, owing to kidney dysfunction
|
|
|
What are the six parts of the nephron?
|
The Glomerulus
Bowman's Capsule (glomerular capsule) Proximal Convoluted Tubule Loop of Henle (Nephron Loop) Distal Convoluted Tubule Collecting Duct |
|
|
True or false: One collecting duct can serve several nephrons
|
True
|
|
|
Describe the make-up a the glomerulus
|
A network of 50 capillaries with many circular fenestrations (pores)
|
|
|
Why is the glomerulus more permeable than typical capillaries and by how much?
|
Larger and more frequent pores;
100-1000 times more permeable |
|
|
What are podocytes?
|
Inner layer of Bowan's Capsule that holds the capillaries in place.
|
|
|
What the nephron loop composed of?
|
A descending and ascending thin limb and an ascending thick portion.
The thin segments are lined with flat squamous cells without microvilli The cubodial cells in the thick segment also lack microvilli |
|
|
Where is the thick segment of the nephron loop located?
|
It runs between the afferent and efferent arterioles
|
|
|
True or false: The distal convoluted tubule is longer than the proximal convoluted tubule
|
FALSE- the distal convoluted tubule is shorter than the proximal convoluted tubule and contains fewer microvilli
|
|
|
Where is the distal convoluted tubule located?
|
It starts at the macula dens and terminates as it empties into the collecting duct.
It is the last segment of the nephron |
|
|
What are the three major functions of the nephron?
|
1) Glomerular Filtraion
2) Tubular Reabsorption 3) Tubular Secretion |
|
|
What is the portion of the blood plasma that enters the glomerular capsule?
|
Glomerular Filtrate
|
|
|
What two mechanisms cause 180 L of fluid to be filtered each day in the glomerular capsule?
|
1) The high hydrostatic pressure of the blood (45 to 60 mmHg) (30-10 mm Hg in normal capillaries) in the glomerulus
2) The large numbers of pores, which are larger than most pores in blood capillaries |
|
|
What substances in the blood are present in the glomerular filtrate?
|
Water, electrolytes, glucose, amino acids, urea, hormones, and vitamins
|
|
|
Why are RBC's, WBC's, and platlets excluded from passage in the glomerular filtrate?
|
Because of their large size
|
|
|
What does the presence of RBC's or protein in the urine indicate?
|
It indicates that the hydrostatic pressure in the glomerular capillaries is excessively high or that there is a defect in the glomerular
|
|
|
What is the average glomerular filtration rate (GFR) per minute?
|
120 ml/min
|
|
|
What two mechanisms regulate GFR via vasoconstriction or vasodilation?
|
Extrinsic (sympathetic nerves) and
Intrinsic (locally produced chemicals) |
|
|
How do you measure GFR (ml/min) ?
|
(Urine volume x Inulin concentration in urine)/ inulin concentration in plasma
|
|
|
What is inulin?
|
A polymer of fructose that is extracted from plants used because our body doesn't make it so it won't be diffused.
|
|
|
What is tubular reabsorption?
|
The transfer of fluid and solutes out of the lumen of the nephron through the interstitial space and into the peritubular capillaries
|
|
|
How much filtrate is reabsorbed from the renal tubules?
|
99%
|
|
|
True or false: tubules have a high reabsorptive capacity for substances needed in the body.
|
True. But tubules have little or no reabsorptive capacity for substances of no vlaue
|
|
|
What is the primary location of tubular reabsorption?
|
In the proximal convoluted tubule, though it occurs throughout the renal tubules
|
|
|
What hormone regulates the reabsorption of Na+ in the distal and collecting ducts?
|
Aldosterone
|
|
|
Under normal conditions, how much glucose filtered is reabsorbed?
|
100%
|
|
|
What the Transport maximum (Tm)?
|
The concentration of transported molecules needed to saturate the carriers and thus achieve maximal transport rate
|
|
|
What is the Tm for glucose?
|
375 mg/minute filtered
|
|
|
What happens to glucose above the Tm?
|
It will not be reabsorbed and will appear in the urine. This mainly occurs in diabetics
|
|
|
Of the fluid going through the nephron, how much is reabsorbed in the proximal convoluted tubule?
the nephron loop? the distal convoluted tubule? the collecting duct? |
Proximal- 80%
Nephron loop- 6% Distal- 9% Collecting- 4% |
|
|
Which portions of the nephron are under ADH control?
|
Distal convoluted tubiles and collecting duct (13%)
|
|
|
Define tubular secretion
|
The secretion of movement of substances from the peritubular capillaries into the lumen of the tubule.
This is a mechanism to selectively move substanves into the lumen for excretion in the urine. |
|
|
What are the three most important substances secreted by the tubules?
|
H+
K+ organic anions- penicillin |
|
|
Why is H+ so important for secretion?
|
H+ regulates acid-case balance. The extent of H+ secretion depends on how acidic the body is and H+ can be secreted in all tubular regions
|
|
|
True or false: The amount of H+ secreted is independent of the amount of bicarbonate reabsorbed
|
False: The amounts of H+ secreted and bicarbonate reabsorbed are interdependent. The reabsorption of bicarbonate occurs as a result of the filtration and secretion and H+
|
|
|
What is acidosis?
|
The ratio of CO2 to HCO3- in the extracellular fluid is increased because of the production of CO2 or an increase in the H+ formation from metabolism.
|
|
|
What is the renal response to acidosis?
|
1) increased amounts of CO2 enter the tubular cells from the extracellular fluid
2) increased amounts of H+ secreated into the lumen of the nephron; some combines with the HCO3- and one Na+ is reabsorbed for each H+ secreted 3) HCO3- in the lumen of the nephron is reabsorbed into the extracellular fluid. The net result is that H+ ions are exreted in the urine and Na+ and HCO3- ions are retained |
|
|
What is alkalosis?
|
The ration of HCO3- increases as the pH rises
|
|
|
What is the renal response to alkalosis?
|
1) decreased amounts of CO2 enter the tubular cells from the extracellular fluid
2) decreased amounts of H+ are secreted into the lumen of the nephron; with less H+ to combine with HCO3-, less HCO3- is reabsorbed. The net result is that H+ ions are retained and bicarbonate ions are excreted. |
|
|
What are the two major mechanisms that kidneys use to regulate the concentration of urine?
|
1) Producing osmotic gradient between the tubular lumen and the surrounding interstitial fluid
2) Amount of ADH secreted from the posterior pituitary |
|
|
At normal fluid balance and solute concentration, what is the value at which body fluids are isotonic?
|
300 millosmols/liter
|
|
|
True or false: The osmolarity of the interstitial fluid throughout the renal cortex is equal to the osmolarity of the fluid in the renal medulla.
|
FALSE: The osmolarity is 300 mosm/L in the renal cortex, but the it increases progressively until it reaches the deepest regions of the medulla and reaches an osmolarity of 1200 to 1400 mosm/L
|
|
|
Which hormone has the greatest affect on Urine Concentration?
|
ADH
|
|
|
When there are low levels of ADH is the urine diluted or concentrated?
|
Diluted (Low levels of ADH make distal tubules and collecting ducts impermeable to water thus excess water is urinated).
|
|
|
When there are high levels of ADH is the urine diluted or concentrated?
|
Concentrated (High levels of ADH make distal tubules and collecting ducts permeable to water thus pulling water out of the urine).
|
|
|
What is the definition of plasma clearance analysis?
|
The ability of the kidneys to "clear" the plasma of substances in a specific length of time (usually ml/min)
|
|
|
True or false: The concentration of cleared (removed) substances from the plasma in the renal veins leaving the kidneys is higher than the concentration in the blood entering the kidneys in the renal artery.
|
FALSE: The concentration is LOWER in the renal veins leaving the kidneys than in the blood entering the kidneys in the renal artery
|
|
|
How do you find volume of cleared plasma per minute?
|
Clearance in ml/min= (UxV)/ P
U= concentration of the substance in 1 ml of urine V= volume of urine formed per minute P= concentration of the substance in 1 ml of plasma |
|
|
How much plasma is filtered per minute?
|
GFR= 120 ml/min (determined by the inulin clearance rate)
|
|
|
True or false: If the amount of a substance in the urine is less than the amount that is filtered in the same time, then tubular reabsorption has taken place.
|
True
|
|
|
True or false: If the amount of a substance excreted in the urine is greater than the amount that is filtered at the same time, tubular reabsorption has taken place.
|
FALSE! Tubular secretion has taken place is the amount excreted is greater than the amount filtered
|
|
|
What part of the nephron produces and secretes renin?
|
Juxtaglomerular apparatus
|
|
|
Where is the juxtaglomerular apparatus located?
|
Where the distal concoluted tubule makes contact with the afferent arteriole near Bowman's capsule
|
|
|
If a substance is filtered and reabsorbed but not secreted what will its plasma clearance rate always be?
|
Less than 120 ml/min
|
|
|
If a substance is filtered and secreted but reabsorbed, what will its plasma clearance rate always be?
|
More than 120 ml/min
|
|
|
What is the blood pressure in the glomerulus capillaries?
|
45-60 mm Hg (10-30 mm Hg in other capillaries)
|
|
|
What percent of water is reabsorbed under the control of ADH?
|
13%
|
|
|
Osmotic concentration is highest in the what?
|
MEDULLA
|
|
|
The ascending limb of the NEPHRON is permeable to what?
|
Ions
|
|
|
The descending limb of the NEPHRON is permeable to what?
|
Water
|
