Term
| excretion of marine boney fish |
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Definition
-cannot produce urine more concentrated than their body fluid
-produce very little urine to conserve water
-excrete ammonia |
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Term
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Definition
-produce dilute urine and conserve salts
-enter estivation during dry periods |
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Term
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Definition
-a state of very low metabolic activity
-before: dilute urin is stored in a large bladder to be used as a source of water |
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Term
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Definition
-occupy a wide range of habitates
-3 adaptations
1.internal fertilization and eggs w/ shells to retard water loss
2. scaly, dry skill that retards water loss
3. excretion of nitrogenous wastes as uric acid solids, losing little water in the process. also,, precipitates in egg so that embryo is not killed by nitrogenous waste. |
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Term
| excretory systems in birds |
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Definition
| -also have internal fertilization, shelled eggs, and excrete uric acid as the nitrogenous waste product. |
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Term
| functional unit of the kidney |
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Definition
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Term
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Definition
1. glomerulus
2. renal tubules
3. peritubular capillaries
-glomerulus and peritubular capillaries lie in series between the arteriole and the venule |
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Term
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Definition
ball of capillaries that filters blood plasma
-filters the blood to produce a fluid that lacks cells and large molecules such as proteins
-arterial blood pressure is the force that drive filtration in the glomerulus
-in nephrons
-all are located in the cortex
-most of the water and solutes filtered in the glomerulus are reabsorbed
-about 12% of the blood recieved is filtered. 2-3 liters of urine (1-2% of the volume filtered |
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Term
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Definition
receive and modify the filtrate
-in nephrons
-begins with bowman's capsule which encloses the glomerulus |
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Term
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Definition
carry substances to and from the renal tubules
-in nephrons |
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Term
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Definition
-towards
-supplies blood underpressure to the glomerulus
-carries blood to each glomerulus. |
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Term
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Definition
-away from
-blood leaves the glomerulus through an efferent arteriole
-gives rise to the peritubular capillaries |
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Term
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Definition
cells of the bowman's capsule that come into direct contact with the glomerular capillaries
-have fine projections that wrap around and cover the capillaries |
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Term
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Definition
fluide that lacks cells and large molecules such as proteins
-produced by glomerulus filtration of blood |
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Term
| composition of the urine in the renal tubule is controlled by... |
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Definition
| cells of the tubule by actively secreting and resorbin specific molecules |
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Term
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Definition
-duct where urine is released
-two kidneys filter blood, process the filtrate into urine, and release the urine into the ureter |
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Term
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Definition
-ureter of each kidney leads to it
-where ruine is stored until it is excreted |
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Term
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Definition
-where urine is excreted through, from the urinary bladder
-two sphincter muscles surring the base of the urethra control the timing of urination.
1. one is smooth muscle, autonomic nervous system
2. skeletal muscle and under voluntary control |
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Term
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Definition
-subunits of the kidney
-include functional units
-make up the medulla of the kidney and are surrounded by the cortex tissue |
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Term
| proximal convoluted tubule |
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Definition
-lie in the cortex of the kidney
-first section of a renal tubule
-has specialized cuboidal cells with thousands of microvilli which greatly increase the surface area for reabsorption of ions and molecules
-the cells have many mitochondria to produce the ATP needed to operate the transport systems (actively transport Na+) |
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Term
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Definition
-after the proximal convoluted tubule
-in the medulla
-makes a hairpin turn within the medulla and continues back up tothe cortex
-when it reaches the cortex it is called the distal convoluted tubule
-functions as a countercurrent multiplier system to increase the solute potential of the surrounding tissue fluid
-creastes a solute concentration gradient int he renal medulla
-segments of the loop are anatomically and functionally different
-divided into the thin descending limb and thin ascending limb, and thick ascending limb.
-desert gerbils have long loops of henle to increase concenctration gradient and conserve water |
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Term
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Definition
-when the loop of henle comes back up to the cortex
-join to form collecting ducts |
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Term
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Definition
| -humans can produce urine that is 4x more concentrated than their blood |
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Term
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Definition
-part of the loop fo henly
-actively moves NaCl out of the filtrate into the tissue fluid.
-not permeable to water, so surrounding tissue becomes more concentrated with NaCl. |
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Term
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Definition
-part of the loop of henle
-permeable to water but not to NaCl. so, water is withdrawn osmotically here
-becomes more concentrated as it nears the turn |
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Term
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Definition
-part of the loop of henle
-not permeable to water but is to NaCl which moves out of the tubule
-fluid reaching the distal convoluted tubule is more dilute than blood plasma, and a concentration gradient is set up in the medulla |
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Term
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Definition
-fluid is now the same concentration as blood plasma but the composition is different
-major solute in the duct is now urea
-as fluid flows down the collecting duct, it loses water osmotically
-some urea leaks out of the duct to the surrounding tissue increasing the osmotic potential ofthe tissue |
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Term
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Definition
-blood pH influences proteins
-bicarbonate ions released from carbonic acid buffer blood |
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Term
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Definition
| hydrogen ions are excreted in the urine and bicarbonate ions are reabsorbed |
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Term
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Definition
| -hydrogen ions are not excreted and bicarbonate ions are not reabsorbed |
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Term
| glomerular filtration rate (GFR) |
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Definition
-stays high
-regulated by the compensation of decreased cardiac output or decreased blood pressure
-ex. dilation of afferent renal arterioles when blood pressure drops
-ex. kidneys release an enzyme called renin |
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Term
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Definition
-enzyme released by kidneys to keep GFR from falling
-activates angiotensin |
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Term
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Definition
-circulating hormone activated by renin
-effects:
1. causes the efferent renal arterioles to constrict to inc. bp in glomerular capillaries
2. causes all peripheral blood vessels to constrict
3. stimulates the adrenal cortex to release aldosterone. this increases water retention and circulatory plasma volume. |
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Term
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Definition
-released by the adrenal cortex by angiotensin
-stimulates greater sodium resorption by the kidney |
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Term
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Definition
causes increased urination
-ex. alcohol |
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Term
| antidiuretic hormone (ADH) |
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Definition
-released by the hypothalamus from loss of blood
-increases permeability of the collecting ducts of the kidneys to water. this increases water resorption and the concentration of the urine. increased water resporption increases blood pressure.
-increases water permeability by stimulating the cellular production and the activity of aquaporins |
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Term
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Definition
| membrane proteins that form water channels |
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Term
| atrial natiuretic peptide (ANP) |
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Definition
| released by the atria of the heart when blood pressure gets abnormally high |
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Term
| when ANP reaches the kidney... |
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Definition
-it decreases the resorption of sodium
-causes an increased loss of sodium and water which lowers blood volume and pressure |
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