Urinary System PDF

urinary system Study online at https://quizlet.com/_g321fi 1. primary functions of kidney: -filter blood -convert filtrate into urine 2. urinary system: kindeys, ureters, urinary bladder, urethra 3. process when filtrate is being converted to urine in the kidneys: - elimination of metabolic w...

urinary system Study online at https://quizlet.com/_g321fi 1. primary functions of kidney: -filter blood -convert filtrate into urine 2. urinary system: kindeys, ureters, urinary bladder, urethra 3. process when filtrate is being converted to urine in the kidneys: - elimination of metabolic waste -regulation of ion levels -regulation of acid base balance -regulation of blood pressure -elimination of biologically active molecules 4. 2 hormones produced by the kidneys: -production and release of erythropoi- etin -formation of calcitriol 5. glucogeogenesis: Kidneys engage in gluconeogenesis during times of fasting or starvation to produce glucose from non-carbohydrate sources. 6. 4 layers of kidney tissue layers from innermost to outermost: -fibrous capsule -perinephric -renal fascia -paranephric 7. fibrous capsule of kidney: dense irregular connective tissue to protect 8. perinephric of kidney: adipose connective tissue for cushion and stabilization 9. renal fascia of kidney: dense irregular connective tissue, anchors the kidney to surrounding structures 10. paranephric of kidney: adipose connective tissue to provide cushion and sta- bilization 11. What would happen to the anatomy of the kidney the supportive tissue defined abovefailed? How would this alter the function of the kidney?: In summary, failure of the supportive tissue in the kidney would undermine its structural and functional integrity, leading to impaired filtration, susceptibility to injury, infec- tions, and potentially irreversible kidney damage. The kidneys' ability to maintain homeostasis in the body—such as regulating fluid, electrolytes, and waste excre- tion—would be severely compromised. 12. innervation of kidney: autonomic nervous sytem -sympathetic nerves extend from spinal cord to kidney blood vessels, decrease urine production -parasympathetic nerves to kidney from the brain with vagus nerve 13. parenchyma: composed of the renal cortex and renal medulla 14. renal cortex: outer layer, contains renal corpuscles 15. renal medulla: inner layer, contains renal pyramids and collecting ducts 1/9  urinary system Study online at https://quizlet.com/_g321fi 16. renal columns: inward extensions of the renal cortex that dip down between the renal pyramids and renal medulla 17. renal pyramid: within renal medulla, contains nephron loop, the tip of each pyramid is called the renal papilla 18. ureter: A muscular tube that carries urine from the kidneys to the bladder for storage. 19. nephron: the microscopic, functional filtration unit of the kidney. contains two major structures, renal corpuscle and renal tubule 20. renal corpuscle: enlarged, round portion of a nephron house within renal cor- tex. composed of glomerulus and glomerular capsule 21. glomerulus: thick tangle of capillary loops. blood enters by an afferent arteriole and exits by an efferent arteriole 22. bowmans capsule (glomerular capsule): two layers -visceral layer: directly overlies glomerulous -parietal layer: simple squamous epithelium -between both layers, theres a capsular space that receives the filtrate to form urine 23. renal tubule: makes up the remaining part of the nephron. contains a proximal convoluted tubule (PCT), nephron loop, and distal convoluted tubule 24. proximal convoluted tubule: first part of renal tubule, simple cuboidal epitheli- um 25. nephron loop (loop of henle): ascending limb and descending limp, go into medulla -keep medulla salty 26. distal convoluted tubule: end of the nephron loop. composed of simple cuboidal epithelium 27. 2 types of nephrons: cortiocal nephrons and junxtamedullary nephrons 28. cortical nephrons: oriented with the renal corpuscle near the peripheral edge of the cortex -barely penetrates the medulla -bulk resides in the cortex -85% of nephrons 29. junxtamedullary nephrons: lie adjacent to the corticomedullary junction -extend deep into the medulla - establish a salt concentration gradient within interstitial space -15% of nephrons 30. collecting tubules and collecting ducts: Collecting tubules drain the DCT into collecting ducts. Multiple Collecting ducts drain the filtrate (now urine) into the renal pelvis 2/9  urinary system Study online at https://quizlet.com/_g321fi 31. 2 specialized epithelial cells do collecting tubules/ducts contain: -Principal cells: cellular receptors to bind aldosterone and antidiuretic -Intercalated cells: types A and B are specialized epithelial cells that regulate urine pH and blood pH 32. intercalated cells type A and B: -Type A: eliminate acid -Type B: eliminate base 33. juxtaglomerular apparatus: important structure that helps regulate filtrate for- mation and systemic blood pressure -granular cells and macula densa cells 34. granular cells: Modified smooth muscle cells of afferent arteriole Located near entrance to renal corpuscle -Contract when stimulated by stretch or sympathetic stimulation -Synthesize, store, and release renin ( required in production of angiotensin) 35. macula densa: modified epithelial cells in the wall of the distal convoluted tubule where it contacts the granular cells -located only in the tubule wall adjacent to the granular cells of the afferent arteriole -narrower and taller than other DCT epithelial cells -detect changes in NaCl contrentration of tubular fluid within the lumen of DCt -signal granular cells in the afferent arteriole to release renin through paracrine stimulation 36. two fluid flow patterns: 1. flow of blood into and out of kidney 2. flow of filtrate, tubular fluid and urine through the nephron and other urinary system structures 37. afferent arteriole: supplies blood to a glomerulus 38. efferent arteriole: vessel for blood to leave glomerulus 1.peritubular capillaries- intertwine around PCT and DCT 2. vasa recta- associated with nephron loop 39. filtrate: plasma minus the large solutes 40. tubular fluid: filtrate after it has entered PCT (reabsorption) and started to manipulate it, it then flows through the nephron loop and DCT 41. urine: tubular fluid is not changed after leaving the collecting ducts and cannot be changed. 42. Urine is formed through 3 processes: 1. glomerular filtration 2. tubular reabsorption 3. tubular secretion 43. filtrate production occurs within....: renal corpuscle -water and solute crosss the filtration membrane and enter corpuscle 44. urine is formed in the kidneys through three interrelated processes: filtra- tion, reabsorption and secretion 3/9  urinary system Study online at https://quizlet.com/_g321fi 45. glomerular filtration: the movement of substances from the blood within the glomerulus into the capsular 46. tubular reabsorption: the movement of substances from tubular fluid back into blood 47. tubular secretion: the movement of substances from the blood into tubular fluid 48. filtration membrane: porous, thin, negatively charged structure which serves as a filter - a substance must pass through all layers of the filter to be excreted 49. 1. endothelium of glomerulus: closest to the lumen -fenestrated; it allows plasma and dissolved substances to be filtered without letting the larger formed elements pass 50. 2. basement membrane of glomerulus: porous basement membrane -composed of glycoprotein and proteoglycan molecules -restricts passage of large plasma proteins such as albumin 51. 3. visceral layer of glomerular capsule: composed of PODOCYTES- octopus like cells that have foot like processes called PEDICLES that wrap around the glomerulus to support capillary wall -pedicals are seperate by thin spaces called FILTRATION SLITS 52. Mesangial cells: modified smooth muscle between capillary loops of glomeru- lus PERICYTES: - form extracellular matrix to support glomerulus - release growth factors to develop glomeruli - release molecules that mediate inflammation +contraction to decrease the surface area of filtration membrane 53. Not all substances are filtered equally at the filtration membrane. There are 3 categories of substances based on their filtration: -freely filtered: small substances like glucose, water, amino acids, ions, urea, small hormones, vitamins b and C -not filtered: formed elements (erythrocytes, leukocytes and platelets), large proteins -limited filtration: proteins that are too large or negatively charged are less likely to be filtered 54. What happens if a substance gets trapped in the filtration membrane: - mesangial cells phagocytize macromolecules that get caught in basement mem- brane, thus help keep filtration membrane clean 55. 3 pressures found in renal corpuscle: -glomerulus hydrostatic pressure -blood colloid osmotic pressure -capsular hydrostatic pressure 4/9  urinary system Study online at https://quizlet.com/_g321fi 56. glomerulus hydrostatic pressure(HPg): -blood pressure in glomerulus -The driving force pushing fluid and solutes out of the capillary - 60mm out 57. blood colloid osmotic pressure (OPg): -pressure opposes HPg - osmotic pressure exerted by blood due to unfiltered dissolved solutes -The opposing pressure driving fluid and solutes back into the capillary - 32 mm in 58. capsular hydrostatic pressure (HPc): - pressure in glomerular capsule due to amount of filtrate already in capsular space - 18 mm in 59. determining net filtration pressure: HP3- (OPg + HPc ) = NFP 60 - (32+18) = NFP NFP= 10 mm Hg 60. A positive net filtration pressure leads to: filtration. 61. A negative net filtration pressure leads to: reabsorption 62. Glomerular filtration rate GFR: -rate at which volume of filtrate is formed (volume per unit time) -net filtration pressure directly inluences GFR -NFP ^ = GFR ^ 63. Variables that increase GFR: -GFR -amount of filtrate formed -solutes and water remaining in tubular fluid -substances in urine 64. Variables that decrease GFR: -filtrate reabsorption 65. macula densa cells: -they moniter NaCl levels in the tubular fluid -indirectly measures blood pressure *If the macula densa detects an abnormally high solute concentration in the tubular fluid, generally indicates low systemic hydration or dehydration 66. GFR is primarily influenced by: -luminal diameter of afferent arterioles -altering surface area of filtration membrane 67. intrinsic control: within kidney - rengal autoregulation that maintains GFR at normal level 68. extrensic control: external to kidney -nervous system regulation to decrease GFR -hormonal regulation to increase GFR 69. renal autoregulation: intrinsic ability to maintain a constant blood pressure and glomerular, filtration rate despite changes in systemic arterial pressure 5/9  urinary system Study online at https://quizlet.com/_g321fi - kidney produces urine at a constant rate despiite fluctuations in systemic blood pressure -functions by a myogenic response and tubuloglomerular feedback 70. myogenic response: contraction and relaxation of smooth muscle in response to stretch 71. tubuloglomerular feedback: backup mechanism to myogenic response in re- sponse to increased systemic blood pressure 72. renal autoregulation: decrease systemic BP: decrease in systemic BP= lower volume of blood entering afferent arteriole -reduce the stretch of smooth muscle in arteriole wall - myogenic response of smooth muscle in vessel results in muslce relaxation -vasodilation -wider vessel allows for more blood (compensates for lower systemic blood pres- sure) -GBP and GFR remain normal 73. renal autoregulation: increase systemic BP: increase in systemic BP= addi- tional volume of blood entering afferent arteriole -stretching the smooth muscle in arteriole wall -myogenic response results in smooth muscle contraction -vasocontriction -narrow vessels=less blood (compensates for higher systemic BP) -MAINTAINS GFR 74. What limitations exist to maintaining GFR with renal autoregulation: renal autoregulation is effective in maintaining a normal glomerular BP only if systemic mean arterial blood pressure remains between 80 and 180 mm Hg 75. decreasing GFR through sympathetic stimulation: -stimulus: stress or emer- gency -vasoconstriction - granular cells of JG apparatus to release renin -renin produces angiotensin II to stimulate mesangial cells to contract, to then decrease filtration surface area, DECREASE GFR, therefore retaining more fluid 76. decreasing GFR through Atrial Natriuretic Peptide (ANP): increases GFR to eliminate fluid -released from atrial cardiac muscle cells in blood in response to stretch -increased stretch -vasodilation -inhibits the release of renin, increase filtration membrane surface -INCREASE GFR -an increase in GFR that increase urine volume and decrease blood volume 6/9  urinary system Study online at https://quizlet.com/_g321fi 77. if youre looking at a list of hormones, asking what is the function, when in doubt say what: it helps us retain fluid, ANP is the only one that eliminates fluid 78. during transcellular transport, a substance must cross two plasma me- branes: -Luminal membrane that is in contact with tubular fluid -Basolateral membrane that rests on basement membrane 79. substances can either pass between the epithelial cells of the what: -para- cellular transport -transcellular transport 80. transport maximum (Tm): Maximum amount of substance that can be reab- sorbed per unit of time 81. renal threshold: maximum plasma concentration of a substance that can be transported in the blood without eventually appearing in the urine 82. Nutrients that are filtered and completely reabsorbed: 1.nutrients: each nutrient has own specific transport proteins 2. small amounts of filtered plasma proteins: insulin or angiotensin, protein is transported from tubular fluid in PCT back into blood, proteins broken down upon transport 83. location of complete reabsorption: proximal convoluted tubule 84. Why do we use the term reclaimed for proteins that get through the filtration membrane instead of reabsorbed?: proteins generally don't filter into the urine because they are too large to pass through the pores in the filtration barrier. 85. if a substance is filtered from the blood and most all is reabsorbed, does the overall level in the blood increase, decrease or stay the same? Why?: stay the same because the kidneys filter the substance and then reabsorb it, effectively removing it temporarily from the blood but putting it back before it is excreted. This prevents any significant increase or decrease in the blood concentration of that substance. 86. Sodium is reabsorbed in the following parts of the nephron: -PCT 65% (the site where most sodium is reabsorbed) -Nephron Loop 25% -DCT 5% -Collecting Duct and Tubule 87. Sodium is ___________ in the tubular fluid and relatively ____________ in the tubulecell. This leads to sodium movement by way of _________________________________. Sodium is then moved into the inter- stitial fluid due to an energyconsuming _______/______ ____________. This leads to _________ levels of sodium inthe interstitial space. Sodium will then move into the ______________ _____________by way of simple diffusion: - -high 7/9  urinary system Study online at https://quizlet.com/_g321fi -low -secondary active transport -Na+/K+ ATPase pump -high -peritubular capillaries 88. aldosterone: -increase Na+ reabsorption -steroid hormone -produced by adrenal cortex -principal cells -increase number sodium chanels and pumps, increase transport maximum -increase blood pressure 89. Atrial natriuretic peptide (ANP): -decrease sodium reabsorption -producede by atria of heart -more sodium and water are excreted in urine -release of ANP, increases urine output -decrease blood volume 90. Water Reabsorption: -due to osmosis -reabsorbed by paracellular transport between cells -reabsorbed by transcellular transport through aquaporins( specific water transport proteins) 91. Site of primary water reabsorption: proximal convulated tubule 92. obligatory water reabsorption: -water movement out of PCT follows sodium by osmosis (little sister following big brother) 93. Antidiuretic hormone (ADH): -released when dehydrated -binds receptors of principal cells of the collecting tubules and ducts -increase migration of vesicles containing aquaporins to the luminal membrane 94. Reabsorption & Secretion of Potassium (K+): -reabsorbed and secreted into tubular fluid - type A intercalated= reabsorb K+ continuously -principal cells= secrete K+ in varying rates 95. Calcium & Phosphate balance: Why do we consider these molecules to- gether?: 99% of the bodys calcium is stored in bone, and the majority is stored as calcium phosphate 96. What prevents Ca2+ from being filtered at the filtration membrane?: its bound to a protein in the blood and is prevented from being filtered 97. Parathyroid hormone (PTH): -released in response to decreased calcium -targets kidney tubules which inhibits potassium reabsorption in PCT -stimulates calcium reabsorption in DCT 8/9  urinary system Study online at https://quizlet.com/_g321fi 98. ________________ move freely across the filtration membrane. Only small amounts of________________ are filtered.If the blood is too acidic, _______________ will be reclaimed and moved into the blood.If the blood is too basic, _________________ will be moved into the blood: -bicarbonate ions -H+ -HCO3 -H+ 99. Bodies main nitrogenous waste products are: -uric acid -urea: recycled in the kidneys to help concentrate solutes in the interstitial fluid of the kidney -creatinine 100. Descending limb of the loop of Henle: The descending limb is permeable to water but impermeable to solutes 101. Ascending limb of the loop of Henle: The ascending limb is impermeable to water but is permeable to solutes 102. micturition: expulsion of urine from the bladder -process 1. sympathetic= storage reflex 2.parasympathetic= micturition reflex 9/9