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70 Cards in this Set
- Front
- Back
Two functions of the kidney:
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1) regulate volume and composition of extracellular fluid (ECF) and 2) excrete waste products from the body.
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Organs of the urinary tract –
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kidneys, ureters, urinary bladder, and urethra.
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Kidneys:
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form urine constantly (drip, drip, drip)
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Ureters:
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carry urine to bladder
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Renal helium –
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the area of the kidney were blood vessels, nerves, and a ureters connect.
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Micturition –
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urination
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Urination occurs when the _________ muscle contracts
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detrusor
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Internal urethral sphincter –
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involuntary muscle
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External urethral sphincter –
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voluntary muscle
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Urinary bladder:
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stores up to 500mL (after which we cannot “hold” it any longer); generally first feel the urge once 200mL has been stored up.
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Urethra:
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carries urine out of the body
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Purpose of kidneys:
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to filter blood. All of it is filtered through multiple times an hour. About 180 liters of fluid a day.
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Minor calyces -> 2-3 major calyces ->
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renal pelvis
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Renal lobe –
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8-15 per kidney. Consists of renal pyramid, renal columns, and the adjacent cortex
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The functional unit of the kidney:
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nephron
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NEPHRON:
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One functional unit of a kidney. Includes the renal corpuscle, the proximal convoluted tubule (PCT), the loop of Henle, the distal convoluted tubule (DCT) and the collecting duct.
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Renal corpuscle –
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Glomerus and bowman’s capsule
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Bowman’s capsule –
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receives filterate
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Kidney Cortex -
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glomerulus, proximal tubule and distal tubule. Where most re-absorption and secretion occurs
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Initial filtering –
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glomerulus
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Arterioles on nephrons at the corticomedullary junction –
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enter a second capillary network, loop of henle
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Two parts of the nephron:
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renal corpuscle and renal tubule
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Three part of the renal tubule:
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1) Proximal convoluted tubule, 2) nephron loop, and 3) distal convoluted tubule
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Cells lining the thick segments of the loop of henle –
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simple Cuboidal
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Cells lining the thin segments of the loop of henle –
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simple squamous
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Kidney Medulla -
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the loop of Henle and collecting ducts
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Kidney blood supply - Aorta → renal artery →
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segmental arteries → interlobar arteries → arcuate arteries → cortical radiate arteries → afferent arterioles (microscopic) → glomerulus (capillary bed) → efferent arteriole → peritubular capillaries (cortical nephron) and vasa recta (juxtamedullary nephron) → venules and veins converge until reaching the renal vein
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From collecting ducts to papillary ducts to minor calyx(es) which drain into…
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renal pelvis ->ureters ->bladder ->urethra
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peritubular capillaries -
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cortical nephron
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vasa recta -
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juxtamedullary nephron
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percent of water re-absorbed from proximal convoluted tubule –
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65%
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Percent of water re-absorbed from descending loop of henle –
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15%
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Percent of water re-absorbed from distal convoluted tubule and collecting ducts –
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19%
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All blood is pumped through the kidneys every ______ minutes
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four
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The kidney’s ability to concentrate urine depends on:
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1)Maintaining a high concentration of solutes and 2) presence of Antidiuretic hormone (makes collecting ducts more permeable.
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The glomerular capillaries are________, i.e. extra leaky.
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Fenestrated
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Not filtered out of the blood:
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red blood cells and proteins.
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Site of urine formation –
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nephron
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Three processes of urine formation –
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1)Glomerular filtration, 2) tubular reabsorption, and 3) tubular secretion.
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Tubular re-absorption –
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when useful substances are put back into the blood stream
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Filtered out:
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salts, glucose, amino acids and water
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Podocytes –
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octopus-like cells that do the actual filtering
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Glomerular capillary blood pressure -
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~60 mmHg (normal is 35 mmHg)
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________ arteriole is more dilated than the _______ one
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afferent…efferent
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Acute renal failure –
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when pressure in the capillary bed drops so much that filtration ceases.
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Nephrons form urine by three processes –
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filtration, reabsorption, and secretion.
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Glomerular filtration rate –
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150 mL/min (or 180 L/day)
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Average urine produced -
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1 mL/minute (1.5 L/day)
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Reabsorption –
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Passage of a substance from the lumen of the tubules through the tubule cells and into the capillaries. This process can involve passive or active transport.
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SECRETION -
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Secretion is the passage of a substance from the capillaries through the tubular cells into the lumen of the tubule.
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Function of Glomerulus –
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Selective filtration
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Function of Proximal convoluted tubule (PCT) -
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Reabsorption of 80% of electrolytes and water; reabsorption of all glucose and amino acids; reabsorption of HCO3-; secretion of H+ and creatinine
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Function of Loop of Henle -
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reabsorption of water in descending loop; Reabsorption of Na+ and Cl- in ascending limb; concentration of filtrate
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Function of Distal convoluted tubule (DCT) -
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Secretion of K+, H+, ammonia; reabsorption of water (regulated by ADH); reabsorption of HCO3-; regulation of Ca2+ and PO42- by parathyroid hormone, reabsorption of Na+ (regulated by aldosterone)
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Function of Collecting duct -
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Reabsorption of water (ADH required)
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Loop of Henle: Descending limb is ________ to water, ascending limb is _________ to water
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permeable…impermeable
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Water is reabsorbed in ________ limb (concentrates urine)
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descending
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Salt is actively reabsorbed in the _______ limb (establishes ability to concentrate even further)
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ascending
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Efferent –
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going away from bowman’s capsule
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Afferent –
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going towards bowman’s capsule
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Distal convoluted tubule reabsorbs even more salt (under the influence of__________, a hormone released from the adrenal cortex.
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Aldosterone
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The ______ ________ reabsorbs water (under the influence of antidiuretic hormone, released from the posterior pituitary gland)
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collecting duct
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Renal Clearance:
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The amount of a substance that “clears” the kidneys (ie. Shows up in the urine) once it enters the tubules
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A good measure of kidney function –
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creatinine clearance
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Pyramid is filled with ________
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collecting ducts
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5 parts of a nephron –
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1) Renal corpuscle, 2) Proximal convoluted tubule, 3) Loop of Henle, 4) Distal convoluted tubule. 5) Collecting duct
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Glomerulus –
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a capillary bed that looks like a knot. Used for filtration.
Unfiltered fluid, blood cells, and plasma proteins leave via the efferent arteriole. Filtered fluid enters tubules and about 1% of it ends up as urine and 99% of it is reabsorbed into preitubular capillarie |
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Purpose of peritubular capillaries:
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reabsorption and secretion (ooops, should have gotten rid of that)
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Reabsorption –
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tubule -> capillary
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Filtration and secretion –
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capillaries -> tubule
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