the pharm lecture on the conventional medications used to treat various urinary conditions, mostly urinary incontinence. the medications used to treat incontinence are chosen depending on the type of incontinence: urge incontinence, which is caused by irritation or stimulation of the bladder's detrusor muscle, can be treated by anti-cholinergics such as oxybutynin and tolterodine, as well as an antidepressant imapramine. overflow incontinence, which is caused by retained urine leaking out of the bladder sphincter, is often related to BPH in men and therefore drugs such as tamsulosin and finasteride are used to relax prostate smooth muscle relaxation and prevent synthesis of dihydrotesterone, the hormone responsible for prostate enlargement, respectively. phenazopyridine is a drug that is used to reduce urinary lining irritation, and has the notable side effect of turning urine and tears yellow.
questions
intro...
1. two sets of bladder muscles?
2. best treatment for stress incontinence?
3. what is urge incontinence due to?
4. most common cause of "transient urge incontinence"?
5. urge incontinence plus symptoms of eye pain, muscle weakness would lead one to suspect what condition?
oxybutynin / ditropan...
6. class / mechanism of action?
7. indications?
8. side effects?
tolterodine / detrol...
9. class / mechanism?
10. comparison to oxybutynin?
imapramine / tofranil...
11. class?
12. mechanism?
13. used when for incontinence?
14. increased risk for what mental symptom?
15. overdose fatal due to what? especially in what age group?
overflow incontinence...
16. definition?
17. in men, overflow incontinence related to...
18. how are diabetes mellitus and MS related to overflow incontinence?
19. two categories of drugs that treat [17]? what do they do?
tamsulosin / flomax...
20. class / mechanism?
21. selectivity for...
22. side effect?
finasteride / proscar...
23. indication?
24. mechanism?
25. proscar is also used for...
26. which patient population should not even handle finasteride tablets and why?
cystitis...
27. dipstick findings...
28. urinalysis findings...
29. three common organisms involved in cystitis?
30. drug of choice to treat cystitis?
phenazopyridine / pyridium...
31. indicated for...
32. potential complication if used during infection?
33. side effects?
answers
1. detrusor around bladder wall, bladder sphincter muscles.
2. kegels.
3. involuntary loss of urine due to overactive detrusor.
4. cystitis.
5. MS.
6. anticholinergic (blocks M3 muscarinic receptor) prevents acetylcholine stimulation of detrusor muscle.
7. urge incontinence and hyperhidrosis.
8. dryness, dizziness, diminished sweating.
9. anticholinergic (blocks M2 and M3 muscarinic receptors)
10. marketed as having fewer side effects than oxybutynin, although this is questionable.
11. antidepressant.
12. blocks reuptake of serotonin and NE and diminishes smooth muscle uptake of acetylcholine.
13. during bed time for enuresis.
14. suicidal ideation.
15. heart block, children.
16. pressure from retained urine overcomes bladder sphincter muscles.
17. BPH.
18. both can reduce sensory input from bladder, allowing for overfilling, as well as decreasing neural input to detrusor muscle, allowing for retention.
19. alpha blockers relax smooth muscle, 5-alpha reductase inhibitors inhibit synthesis of dihydrotestosterone.
20. alpha 1 receptor antagonist leads to smooth muscle relaxation.
21. alpha 1 A receptors in prostate, instead of alpha 1 B in blood vessels.
22. possible retrograde ejaculation.
23. functional incontinence.
24. blocks conversion of testosterone into DHT.
25. male pattern baldness.
26. pregnant women-- category X drug that can be absorbed through the skin.
27. positive leukocyte esterase, nitrite, hemoglobin.
28. WBC's, RBC's, bacteria.
29. ecoli, staph, enterococci.
30. TMP-sulfa.
31. irritation of urinary tract lining.
32. analgesic effects may prevent awareness of infection spreading to kidneys.
33. turns urine and tears yellow / orange.
Showing posts with label urinary. Show all posts
Showing posts with label urinary. Show all posts
Sunday, November 14, 2010
Wednesday, February 4, 2009
organ systems: embryology of the urinary systems
[picture courtesy of erika yosefah william shortbread zelfand]
this lecture is the last in the series of the kidney and looks at renal embryology. kidney development can be roughly divided into three phases: pronephros, mesonephros, and metanephros. pronephros is both the early evolutionary form of the renal filtering system and also the first stage in human kidney development. mesonephros has nephrons with glomeruli and s-shaped tubules, which filter blood from the aorta and drain it into the gut tube via the mesonephric duct. the formation of the last stage, metanephros, begins with signalling factors from the metanephrogenic mesenchyme that stimulate the growth of the "uretic bud" from the lower part of the mesonephric duct. the uretic bud branches out and anastomoses to form the renal tubules and framework for the kidney. one additional note regarding early development: the urorectal septum divides the gut tube into the anorectal canal and the urogenital sinus, which form the urinary and GI tracts.
some pathologies of kidney development: if kidney fails to "ascend" (a misnomer because the kidney stays in place while the body grows downwards) to its position deep to the 12th rib, this is called pelvic kidney. horseshoe kidney is the fusion of the kidneys below the inferior mesenteric artery, and a failure to ascend. duplications of a kidney / supernumerary kidney can occur if the uretic bud divides prior to the development of the metanephric mesoderm. agenesis is the lack of development of uretic bud, leading to inadequate contact between mesoderm and uretic bud, leading to lack of a kidney.
questions
1. urogenital and reproductive systems develop from..
2. early nephrons develop in...
3. what are the three stage is kidney development?
4. what are the characteristics of the mesonephros stage?
5. urine formation begins...
6. describe the excretion of metabolic waste in the embryo.
7. uretic bud branches out from...
8. what are the renal tubules formed by?
9. metanephrogenic mesenchyme initiates growth of uretic bud via...
10. what are the collecting ducts formed by?
11. what is the "ascent of the kidney"?
12. what is the urorectal septum's role in renal development?
13. what is pelvic kidney?
14. what is horseshoe kidney?
15. what is duplications of the kidney?
16. what is agenesis of the kidney?
answers
1. urogenital ridges of intermediate mesoderm.
2. lateral part of urogenital ridge.
3. pronephros, mesonephros, metanephros
4. nephrons consisting of glomeruli and S-shaped tubules, which filter blood from the aorta, and a duct that drains into the gut tube.
5. ~9 weeks
6. metabolic wastes are dumped into the gut via the mesonephric duct, absorbed into blood and transported across placental wall for removal.
7. mesonephric duct
8. repeated dichotomous branching of the developing metanephron.
9. signalling factors
10. uretic bud
11. the apparent ascent due to the growth of the embryo caudal to the kidneys.
12. the urorectal septum divdes the gut tube into the GI tube and the urinary system.
13. no ascent of kidney
14. kidneys fuse below inferior mesenteric artery and do not ascend
15. double kidneys develop because ureteric bud divides prior to development of metanephric mesoderm
16. lack of development of uretic bud leading to inadequate contact between bud and mesoderm.
Tuesday, February 3, 2009
organ systems: acid base balance and urinary system
this lecture is an introduction to body pH and the mechanisms that regulate it: the kidneys, the lungs, and chemical buffers. it also talks about the development of kidney stones and the physiology of the bladder.
body pH is largely determined by the balance between the acidic carbon dioxide and the basic bicarbonate. recall from respiratory physiology that carbon dioxide combines with water in cells via carbonic anhydrase to form carbonic acid, which then dissociates into bicarbonate and H+. the body can develop alkalosis or acidosis due to an imbalance of these molecules; acidosis can occur either by hypoventilation (retaining too much CO2) or through metabolic pathways- loss of bicarbonate through diarrhea, renal failure, buildup of lactic acid from exercise, excess ketone body production in the case of diabetes mellitus. alkalosis can occur by hyperventilation (loss of too much CO2 from lungs) or by ingestion of antacids, excess secretion of H+ in the kidneys due to hypertension, or vomiting of acidic HCl.
in order to regulate the pH, the body can increase or decrease the ventilation rate to regulate blood CO2 levels. another main source of pH regulation is in the kidneys via the balance between reabsorption and excretion of bicarbonate and H+. bicarbonate in the blood is filtered in the kidneys and combines with H+ secreted by the epithelial cells of the proximal tubule. this forms carbonic acid, which can be converted back into CO2 and H2O via carbonic anhydrase. the CO2 then diffuses back into the epithelial cells, where it reforms bicarbonate and H+ through the reverse reaction. in this way 99% of bicarbonate filtered through the kidney is reabsorbed.
if the acidity in the blood is too high, then H+ secreted into the lumen will be higher than the bicarbonate in the filtrate, and excess H+ will be bound to ammonia and phosphate buffers and excreted, raising the pH. conversely, if the blood is basic, then there will be more bicarbonate than H+, and the excess will be unable to be reabsorbed as CO2 and thus be excreted, lowering the pH. angiotensin II and aldosterone can both cause excess H+ secretion, resulting in low pH- angiotensin II stimulates the PCT Na+/H+ cotransporters in the tubular epithelia, while aldosterone stimulates the Na+/H+ antiporter, as well as stimulating intercalated cell secretion of H+. this means that the high angiotensinII and aldosterone levels associated with hypertension also result in a lower pH.
a brief look at kidney stones: when there is excess insoluble material in the filtrate or excess water reabsorption, sometimes stones can develop in the kidney and block urine passage. the most common is the calcium oxalate stone, which develops from a hyper-reabsorption of calcium and oxalate from the intestines, which then combine in the kidneys. a second type of kidney stone is struvite, which forms from a bacterial enzyme, urease, which degrades urea into NH3, which raises pH and forms MgNH4PO4 stones.
the urine that forms in the kidney then goes out via the ureters into the bladder. the bladder is surrounded by the detrusor muscle, and has openings that lead out into the urethra, which leads out into the outside world. the urethral sphincter has two layers, the inner sphincter, which is controlled by parasympathetic smooth muscle, and the outer layer, which is controlled by voluntary striated muscle (pudendal nerve, S2,3,4). when the bladder is filling, the detrusor muscle relaxes and the inner sphincter contracts. during the micturition (urination) reflex, the detrusor muscle contracts and the inner sphincter relaxes.
questions
1. what is blood pH regulated by?
2. what is the main chemical buffer in the blood?
3. how do the lungs regulate pH?
4. how do the kidneys regulate pH?
5. what are the pH limits of the body and what occurs beyond the limits?
6. what are the sources of acidity in the body?
7. acidity depends on the ratio between...
8. the reaction that produces bicarbonate from CO2 is catalyzed by...
9. what is the pKa of bicarbonate and what happens at the physiologic pH of 7.4?
10. why is urine continuously acidified?
11. what are the two sources for production of CO2 in the body?
12. describe the ultimate fate of CO2.
13. describe the reabsorption of bicarbonate in the proximal convoluted tubules of the kidney.
14. describe the reabsorption of bicarbonate in the proximal convoluted tubules when there is an acid load.
15. describe acid secretion in the distal convoluted tubules.
16. what is the phosphate buffer? what does it do?
17. what is the major buffer system for excess H+ ions?
18. ammonium buffer produced from...
19. describe the path of the ammonium buffer through the nephron.
20. what is "bicarbonate addition"?
21. how do low potassium levels contribute to an acid urine?
22. what effect does angiotensin II have on H+ secretion?
23. what are the three ways in which aldosterone increases H+ secretion?
24. what is the body's response to respiratory acidosis?
25. what is the body's response to respiratory alkalosis?
26. what are four potential causes of metabolic acidosis?
27. what is the body's response to metabolic acidosis?
28. what are three potential causes of metabolic alkalosis?
29. what is the body's response to metabolic alkalosis?
30. what is the cause of kidney stones?
31. what is the most common type of kidney stone and what is it caused by?
32. what are struvite stones and how are they formed?
33. what is the muscle that contracts in the bladder?
34. what is the trigone?
35. in males, external and internal urethral sphincters are separated by...
36. how long is the urethra in males vs. females?
37. describe the difference between the internal vs. external urethral sphincters in females.
38. bladder filling is mediated by the...
39. baroreceptor sensory neurons in the bladder stimulates...
40. pressure waves are ...
41. what is the nerve that controls the external urethral sphincter?
answers
1. chemical buffers, kidneys, lungs.
2. bicarbonate
3. expiration of CO2 reduces acidity.
4. excess H+ ions are excreted, bound to phosphate and other buffers.
5. a pH below 7.0 results in a depressed CNS state- leading to coma and death. a pH above 7.8 results in an overactive CNS: leading to nervousness, muscle tetany, convulsions.
6. CO2 is derived from metabolism and is a volatile source of acidity. phosphoric, sulfuric, and hydrochloric acids are non volatile sources of acids and are derived from nucleic acid/protein/amino acid metabolism.
7. bicarbonate to carbon dioxide.
8. carbonic anhydrase.
9. pKa of bicarbonate is 6.1- at the body's pH of 7.4, CO2 is constantly removed.
10. because the basic bicarbonate is being selectively reabsorbed to maintain the buffer system, and the excess H+ from the dietary acid loads are being filtered and excreted.
11. metabolism produces CO2. H+ from non volatile acids can also combine with bicarbonate and create CO2.
12. CO2 combines with water to form carbonic acid, which dissociates into bicarbonate and H+ ion. in the kidney, H+ is secreted and bicarbonate is reabsorbed.
13. hydrogen ion is secreted into the lumen, where it combines with bicarbonate to form carbonic acid, which is converted to CO2 and H2O by carbonic anhydrase. CO2 then diffuses through the epithelial membrane and reforms bicarbonate, which is then reabsorbed into circulation.
14. when there is an acid load, there is more H+ than the level of bicarbonate- excess H+ is bound to ammonia and phosphate and excreted. (any excess bicarbonate is simply excreted)
15. bicarbonate has been mostly reabsorbed in the proximal tubules, so H+ is simply secreted by the ATPase pumps in the intercalated cells and lowers the pH of the lumen to approximately 4.5.
16. the phosphate buffer combines with excess H+ secreted into the lumen and aids in its excretion.
17. the ammonia buffer system.
18. glutamine in proximal convoluted tubule
19. ammonia combines with H+ in the proximal tubule, and is reabsorbed in the thick ascending limb, and is then secreted back into the tubule at the distal convoluted tubule and the collecting duct.
20. each H+ ion that is secreted, buffered, and excreted is dissociated from carbonic acid, forming bicarbonate which can then reenter circulation.
21. low blood potassium levels pull K+ ions out via a K+/H+ antiporter, thereby pulling in H+ ions which are then secreted into the urine.
22. angiotensin II stimulates the PCT Na/H contransporters, which facilitate Na reabsorption and H secretion.
23. aldosterone stimulates the intercalated cell secretion of H+, stimulates the Na/H antiporter, and upregulates the Na/K pump (thereby stimulating the Na/H antiporter)
24. the excess H+ that is produced by excess CO2 in the body is secreted and bound to ammonia and phosphate buffers and excreted, thereby raising pH. every H+ ion that is excreted also corresponds to a new bicarbonate ion which can be used to buffer the pH further.
25. less H+ is secreted, allowing excess bicarbonate to be excreted.
26. excess bicarbonate being lost through diarrhea, renal failure (H+ not being secreted fast enough), acidic ketone bodies created from diabetes mellitus, and lactic acid produced from anaerobic respiration.
27. H+ secretion and bicarbonate addition in the kidneys, as well as hyperventilating reducing CO2 levels in the blood.
28. ingestion of antacids, excess H+ loss due to aldosterone or hypokalemia, or loss of HCl through vomiting.
29. less H+ is secreted, allowing excess bicarbonate to be excreted from the kidneys. hypoventilation also raises CO2 levels in the blood.
30. excess insoluble materials or water reabsorption causes stones to precipitate out.
31. calcium oxalate, due to both high calcium levels (from intestinal hyperabsorption or defective renal absorption) and high oxalate levels (intestinal over-absorption)
32. MgNH4PO4, caused by urease action of bacterial infection.
33. detrusor muscle.
34. the triangular area in the bladder between the two ureteric orifices and the urethral opening.
35. the prostate.
36. 20cm in males, 4 cm in females
37. internal urethral sphincter is involuntary, smooth muscle, controlled by autonomic nervous system, and relaxes when bladder is expanded. exteral sphincter is voluntary, striated muscle, controlled by pudendal nerve.
38. sympathetic nervous system
39. relaxation of detrusor muscle and constriction of internal urethral sphincter.
40. parasympathetic micturition reflexes- alternating detrusor contraction and relaxation along with internal urethral sphincter relaxation.
41. pudendal (S2,3,4)
body pH is largely determined by the balance between the acidic carbon dioxide and the basic bicarbonate. recall from respiratory physiology that carbon dioxide combines with water in cells via carbonic anhydrase to form carbonic acid, which then dissociates into bicarbonate and H+. the body can develop alkalosis or acidosis due to an imbalance of these molecules; acidosis can occur either by hypoventilation (retaining too much CO2) or through metabolic pathways- loss of bicarbonate through diarrhea, renal failure, buildup of lactic acid from exercise, excess ketone body production in the case of diabetes mellitus. alkalosis can occur by hyperventilation (loss of too much CO2 from lungs) or by ingestion of antacids, excess secretion of H+ in the kidneys due to hypertension, or vomiting of acidic HCl.
in order to regulate the pH, the body can increase or decrease the ventilation rate to regulate blood CO2 levels. another main source of pH regulation is in the kidneys via the balance between reabsorption and excretion of bicarbonate and H+. bicarbonate in the blood is filtered in the kidneys and combines with H+ secreted by the epithelial cells of the proximal tubule. this forms carbonic acid, which can be converted back into CO2 and H2O via carbonic anhydrase. the CO2 then diffuses back into the epithelial cells, where it reforms bicarbonate and H+ through the reverse reaction. in this way 99% of bicarbonate filtered through the kidney is reabsorbed.
if the acidity in the blood is too high, then H+ secreted into the lumen will be higher than the bicarbonate in the filtrate, and excess H+ will be bound to ammonia and phosphate buffers and excreted, raising the pH. conversely, if the blood is basic, then there will be more bicarbonate than H+, and the excess will be unable to be reabsorbed as CO2 and thus be excreted, lowering the pH. angiotensin II and aldosterone can both cause excess H+ secretion, resulting in low pH- angiotensin II stimulates the PCT Na+/H+ cotransporters in the tubular epithelia, while aldosterone stimulates the Na+/H+ antiporter, as well as stimulating intercalated cell secretion of H+. this means that the high angiotensinII and aldosterone levels associated with hypertension also result in a lower pH.
a brief look at kidney stones: when there is excess insoluble material in the filtrate or excess water reabsorption, sometimes stones can develop in the kidney and block urine passage. the most common is the calcium oxalate stone, which develops from a hyper-reabsorption of calcium and oxalate from the intestines, which then combine in the kidneys. a second type of kidney stone is struvite, which forms from a bacterial enzyme, urease, which degrades urea into NH3, which raises pH and forms MgNH4PO4 stones.
the urine that forms in the kidney then goes out via the ureters into the bladder. the bladder is surrounded by the detrusor muscle, and has openings that lead out into the urethra, which leads out into the outside world. the urethral sphincter has two layers, the inner sphincter, which is controlled by parasympathetic smooth muscle, and the outer layer, which is controlled by voluntary striated muscle (pudendal nerve, S2,3,4). when the bladder is filling, the detrusor muscle relaxes and the inner sphincter contracts. during the micturition (urination) reflex, the detrusor muscle contracts and the inner sphincter relaxes.
questions
1. what is blood pH regulated by?
2. what is the main chemical buffer in the blood?
3. how do the lungs regulate pH?
4. how do the kidneys regulate pH?
5. what are the pH limits of the body and what occurs beyond the limits?
6. what are the sources of acidity in the body?
7. acidity depends on the ratio between...
8. the reaction that produces bicarbonate from CO2 is catalyzed by...
9. what is the pKa of bicarbonate and what happens at the physiologic pH of 7.4?
10. why is urine continuously acidified?
11. what are the two sources for production of CO2 in the body?
12. describe the ultimate fate of CO2.
13. describe the reabsorption of bicarbonate in the proximal convoluted tubules of the kidney.
14. describe the reabsorption of bicarbonate in the proximal convoluted tubules when there is an acid load.
15. describe acid secretion in the distal convoluted tubules.
16. what is the phosphate buffer? what does it do?
17. what is the major buffer system for excess H+ ions?
18. ammonium buffer produced from...
19. describe the path of the ammonium buffer through the nephron.
20. what is "bicarbonate addition"?
21. how do low potassium levels contribute to an acid urine?
22. what effect does angiotensin II have on H+ secretion?
23. what are the three ways in which aldosterone increases H+ secretion?
24. what is the body's response to respiratory acidosis?
25. what is the body's response to respiratory alkalosis?
26. what are four potential causes of metabolic acidosis?
27. what is the body's response to metabolic acidosis?
28. what are three potential causes of metabolic alkalosis?
29. what is the body's response to metabolic alkalosis?
30. what is the cause of kidney stones?
31. what is the most common type of kidney stone and what is it caused by?
32. what are struvite stones and how are they formed?
33. what is the muscle that contracts in the bladder?
34. what is the trigone?
35. in males, external and internal urethral sphincters are separated by...
36. how long is the urethra in males vs. females?
37. describe the difference between the internal vs. external urethral sphincters in females.
38. bladder filling is mediated by the...
39. baroreceptor sensory neurons in the bladder stimulates...
40. pressure waves are ...
41. what is the nerve that controls the external urethral sphincter?
answers
1. chemical buffers, kidneys, lungs.
2. bicarbonate
3. expiration of CO2 reduces acidity.
4. excess H+ ions are excreted, bound to phosphate and other buffers.
5. a pH below 7.0 results in a depressed CNS state- leading to coma and death. a pH above 7.8 results in an overactive CNS: leading to nervousness, muscle tetany, convulsions.
6. CO2 is derived from metabolism and is a volatile source of acidity. phosphoric, sulfuric, and hydrochloric acids are non volatile sources of acids and are derived from nucleic acid/protein/amino acid metabolism.
7. bicarbonate to carbon dioxide.
8. carbonic anhydrase.
9. pKa of bicarbonate is 6.1- at the body's pH of 7.4, CO2 is constantly removed.
10. because the basic bicarbonate is being selectively reabsorbed to maintain the buffer system, and the excess H+ from the dietary acid loads are being filtered and excreted.
11. metabolism produces CO2. H+ from non volatile acids can also combine with bicarbonate and create CO2.
12. CO2 combines with water to form carbonic acid, which dissociates into bicarbonate and H+ ion. in the kidney, H+ is secreted and bicarbonate is reabsorbed.
13. hydrogen ion is secreted into the lumen, where it combines with bicarbonate to form carbonic acid, which is converted to CO2 and H2O by carbonic anhydrase. CO2 then diffuses through the epithelial membrane and reforms bicarbonate, which is then reabsorbed into circulation.
14. when there is an acid load, there is more H+ than the level of bicarbonate- excess H+ is bound to ammonia and phosphate and excreted. (any excess bicarbonate is simply excreted)
15. bicarbonate has been mostly reabsorbed in the proximal tubules, so H+ is simply secreted by the ATPase pumps in the intercalated cells and lowers the pH of the lumen to approximately 4.5.
16. the phosphate buffer combines with excess H+ secreted into the lumen and aids in its excretion.
17. the ammonia buffer system.
18. glutamine in proximal convoluted tubule
19. ammonia combines with H+ in the proximal tubule, and is reabsorbed in the thick ascending limb, and is then secreted back into the tubule at the distal convoluted tubule and the collecting duct.
20. each H+ ion that is secreted, buffered, and excreted is dissociated from carbonic acid, forming bicarbonate which can then reenter circulation.
21. low blood potassium levels pull K+ ions out via a K+/H+ antiporter, thereby pulling in H+ ions which are then secreted into the urine.
22. angiotensin II stimulates the PCT Na/H contransporters, which facilitate Na reabsorption and H secretion.
23. aldosterone stimulates the intercalated cell secretion of H+, stimulates the Na/H antiporter, and upregulates the Na/K pump (thereby stimulating the Na/H antiporter)
24. the excess H+ that is produced by excess CO2 in the body is secreted and bound to ammonia and phosphate buffers and excreted, thereby raising pH. every H+ ion that is excreted also corresponds to a new bicarbonate ion which can be used to buffer the pH further.
25. less H+ is secreted, allowing excess bicarbonate to be excreted.
26. excess bicarbonate being lost through diarrhea, renal failure (H+ not being secreted fast enough), acidic ketone bodies created from diabetes mellitus, and lactic acid produced from anaerobic respiration.
27. H+ secretion and bicarbonate addition in the kidneys, as well as hyperventilating reducing CO2 levels in the blood.
28. ingestion of antacids, excess H+ loss due to aldosterone or hypokalemia, or loss of HCl through vomiting.
29. less H+ is secreted, allowing excess bicarbonate to be excreted from the kidneys. hypoventilation also raises CO2 levels in the blood.
30. excess insoluble materials or water reabsorption causes stones to precipitate out.
31. calcium oxalate, due to both high calcium levels (from intestinal hyperabsorption or defective renal absorption) and high oxalate levels (intestinal over-absorption)
32. MgNH4PO4, caused by urease action of bacterial infection.
33. detrusor muscle.
34. the triangular area in the bladder between the two ureteric orifices and the urethral opening.
35. the prostate.
36. 20cm in males, 4 cm in females
37. internal urethral sphincter is involuntary, smooth muscle, controlled by autonomic nervous system, and relaxes when bladder is expanded. exteral sphincter is voluntary, striated muscle, controlled by pudendal nerve.
38. sympathetic nervous system
39. relaxation of detrusor muscle and constriction of internal urethral sphincter.
40. parasympathetic micturition reflexes- alternating detrusor contraction and relaxation along with internal urethral sphincter relaxation.
41. pudendal (S2,3,4)
Tuesday, December 2, 2008
histology: urinary system
this unit provided a brief histological overview of the kidneys and the tubular architecture of the urinary system. the basic function of the kidneys is to filter the blood and excrete waste through the urine, which leaves the kidney via the ureter, is pooled in the bladder, then goes from the bladder to the body's exterior by means of the urethra. inside the kidney itself there is an outer layer called the cortex and an inner layer called the medulla, which contains triangular shaped lobes called medullary pyramids. the pyramids collect urine at their tips, called area cribosa, into the calyces, which drain into the renal sinuses, renal pelvis, and out to the ureter. the kidney is filled with functional tubular units called the nephron, of which there are two types: juxtamedullary and cortical, depending on their location.
the site of filtration of blood occurs at the glomerulus, which is a ball of type 2 fenestrated capillaries inside a Bowman's capsule. the Bowman's capsule is similar to a pericardium or pleura in that it has a visceral and parietal layer and a space in between; in this case, the visceral layer is made up of the layer of podocytes that encase the ball of capillaries and provide an extra filtration layer, outside of which there is the bowman's space, and then the parietal bowman's capsule. the blood supply to the ball of capillaries comes from the afferent arteriole and leaves through the efferent arteriole; this end of the glomerulus is called the vascular pole. on the other side of the glomerulus is the urinary pole, which collects the filtrate from the blood into the proximal tubule, which is a convoluted tubule made of simple cuboidal epithelium with extensive apical microvilli. this tubule descends into the medullary region and becomes the loop of Henle, which is thin and squamous on the way down and thick and cuboidal on the way up. this turns into the distal convoluted tubule, which comes back to the glomerulus to form the juxtamedullary complex, which is a junction of the distal tubule and the efferent arteriole, with a group of cells called the macula densa in between. the distal tubule then dumps into a collecting duct, which empties into the papillary ducts that empty into the area cribrosa of the medullary pyramids, and out the body as covered above.
the blood flow in and out of the kidney is as follows: the visceral abdominal aorta supplies the blood to the renal artery, which branches into the interlobular arteries, which branch into the arcuate arteries, which branch into the interlobular arteries, which branch into the intralobular arteries, which turn into afferent arterioles and enter the glomerulus. the blood is filtered in the capillaries in the glomerulus, then flows out through the efferent arteriole, then enters peritubular capillaries, which are small capillaries that run alongside nephron tubules and are the link between the arteries and veins in the kidneys. from the peritubular capillaries, blood flows into veins and exits in the opposite order: intralobular, interlobular, etc etc.
some details about the epithelium of the plumbing of the urinary system: there is transitional epithelium basically from the ureter to the end of the urethra, which switches to non-keratinized stratified squamous. the muscularis externa of the ureter and urethra has opposite layers than other tubes of the body in that has an inner longitudinal and outer circular layer. the urinary bladder has a thick and choatic muscularis externa.
questions
1. what are four functions of the urinary system?
2. describe the anatomy of the kidney.
3. describe the blood flow in and out of the kidney.
4. what are the two types of nephrons?
5. describe the anatomy of a glomerulus.
6. what are the two poles in a glomerulus?
7. what is the glomelular membrane composed of?
8. describe the proximal tubule.
9. describe the loop of Henle.
10. describe the distal tubule.
11. what is a juxtaglomerular apparatus?
12. describe the collecting ducts.
13. describe juxtaglomerular cells.
14. what are peritubular capillaries?
15. describe the ureter.
16. describe the urinary bladder.
17. describe the epithelium of the urethra.
18. describe the muscularis externa of the urethra.
answers
1. chemically balance the blood, remove wastes, regulate blood pressure, and regulate red blood cell production.
2. kidneys have an outer layer called cortex and inner layer called medulla. in the medulla there are medullary pyramids from which urine is collected from the tips (area cribrosa) to the minor and major calyces, which converge into the renal sinuses, which converge into the renal pelvis, which leads out to the ureter.
3. renal artery to interlobar artery to arcuate artery to interlobular artery to intralobular artery to afferent arteriole to glomelular capsule to intralobular vein to interlobular vein to arcuate vein to interlobar vein to renal vein.
4. cortical nephrons and juxtamedullary nephrons.
5. 1-20 type II capillaries held together by a mesangium, encased in podocytes which make up the visceral Bowman's capsule, outside of which is the Bowman's space, and then the parietal Bowman's capsule.
6. vascular pole contains the afferent and efferent arterioles. urinary pole is on the other end of the glomerulus, where the proximal tubule starts.
7. type II capillary endothelium, endothelial basement membrane, podocyte basement membrane, podocyte, occasional mesangial cell.
8. long, convoluted, does most of the absorption, simple cuboidal with extensive apical microvilli.
9. has a thin, squamous descending section and a thick, ascending, cuboidal section.
10. simple suboidal, no microvilli. convolutes and feeds into a collecting duct.
11. the junction between a distal tubule and a vascular pole, with a macula densa in between
12. a large diameter tube that is the common collecting point for a number of nephrons, and merges into papillary ducts to the area cribrosa. simple cuboidal with rounded apical surfaces.
13. modified smooth muscle cells that secrete renin, which catalyzes formation of angiotensin-- regulates blood pressure.
14. the capillaries found of the back sides of nephric tubules and serve as points for absorption, the link between arterial and venous blood vasculature.
15. long muscular tube from renal pelvis to bladder with transitional epithelium and lamina propria (but no muscularis mucosa) muscularis externa has "reversed" layers -- inner longitudinal outer circular.
16. distensible sac with transitional epithelium and lamina propria but no muscularis mucosa. muscularis externa thick and chaotic.
17. PSC epithelium, near bladder is more transitional, near exterior is more non keratinzed stratified squamous. muscularis externa has inner longitudinal, outer circular.
the site of filtration of blood occurs at the glomerulus, which is a ball of type 2 fenestrated capillaries inside a Bowman's capsule. the Bowman's capsule is similar to a pericardium or pleura in that it has a visceral and parietal layer and a space in between; in this case, the visceral layer is made up of the layer of podocytes that encase the ball of capillaries and provide an extra filtration layer, outside of which there is the bowman's space, and then the parietal bowman's capsule. the blood supply to the ball of capillaries comes from the afferent arteriole and leaves through the efferent arteriole; this end of the glomerulus is called the vascular pole. on the other side of the glomerulus is the urinary pole, which collects the filtrate from the blood into the proximal tubule, which is a convoluted tubule made of simple cuboidal epithelium with extensive apical microvilli. this tubule descends into the medullary region and becomes the loop of Henle, which is thin and squamous on the way down and thick and cuboidal on the way up. this turns into the distal convoluted tubule, which comes back to the glomerulus to form the juxtamedullary complex, which is a junction of the distal tubule and the efferent arteriole, with a group of cells called the macula densa in between. the distal tubule then dumps into a collecting duct, which empties into the papillary ducts that empty into the area cribrosa of the medullary pyramids, and out the body as covered above.
the blood flow in and out of the kidney is as follows: the visceral abdominal aorta supplies the blood to the renal artery, which branches into the interlobular arteries, which branch into the arcuate arteries, which branch into the interlobular arteries, which branch into the intralobular arteries, which turn into afferent arterioles and enter the glomerulus. the blood is filtered in the capillaries in the glomerulus, then flows out through the efferent arteriole, then enters peritubular capillaries, which are small capillaries that run alongside nephron tubules and are the link between the arteries and veins in the kidneys. from the peritubular capillaries, blood flows into veins and exits in the opposite order: intralobular, interlobular, etc etc.
some details about the epithelium of the plumbing of the urinary system: there is transitional epithelium basically from the ureter to the end of the urethra, which switches to non-keratinized stratified squamous. the muscularis externa of the ureter and urethra has opposite layers than other tubes of the body in that has an inner longitudinal and outer circular layer. the urinary bladder has a thick and choatic muscularis externa.
questions
1. what are four functions of the urinary system?
2. describe the anatomy of the kidney.
3. describe the blood flow in and out of the kidney.
4. what are the two types of nephrons?
5. describe the anatomy of a glomerulus.
6. what are the two poles in a glomerulus?
7. what is the glomelular membrane composed of?
8. describe the proximal tubule.
9. describe the loop of Henle.
10. describe the distal tubule.
11. what is a juxtaglomerular apparatus?
12. describe the collecting ducts.
13. describe juxtaglomerular cells.
14. what are peritubular capillaries?
15. describe the ureter.
16. describe the urinary bladder.
17. describe the epithelium of the urethra.
18. describe the muscularis externa of the urethra.
answers
1. chemically balance the blood, remove wastes, regulate blood pressure, and regulate red blood cell production.
2. kidneys have an outer layer called cortex and inner layer called medulla. in the medulla there are medullary pyramids from which urine is collected from the tips (area cribrosa) to the minor and major calyces, which converge into the renal sinuses, which converge into the renal pelvis, which leads out to the ureter.
3. renal artery to interlobar artery to arcuate artery to interlobular artery to intralobular artery to afferent arteriole to glomelular capsule to intralobular vein to interlobular vein to arcuate vein to interlobar vein to renal vein.
4. cortical nephrons and juxtamedullary nephrons.
5. 1-20 type II capillaries held together by a mesangium, encased in podocytes which make up the visceral Bowman's capsule, outside of which is the Bowman's space, and then the parietal Bowman's capsule.
6. vascular pole contains the afferent and efferent arterioles. urinary pole is on the other end of the glomerulus, where the proximal tubule starts.
7. type II capillary endothelium, endothelial basement membrane, podocyte basement membrane, podocyte, occasional mesangial cell.
8. long, convoluted, does most of the absorption, simple cuboidal with extensive apical microvilli.
9. has a thin, squamous descending section and a thick, ascending, cuboidal section.
10. simple suboidal, no microvilli. convolutes and feeds into a collecting duct.
11. the junction between a distal tubule and a vascular pole, with a macula densa in between
12. a large diameter tube that is the common collecting point for a number of nephrons, and merges into papillary ducts to the area cribrosa. simple cuboidal with rounded apical surfaces.
13. modified smooth muscle cells that secrete renin, which catalyzes formation of angiotensin-- regulates blood pressure.
14. the capillaries found of the back sides of nephric tubules and serve as points for absorption, the link between arterial and venous blood vasculature.
15. long muscular tube from renal pelvis to bladder with transitional epithelium and lamina propria (but no muscularis mucosa) muscularis externa has "reversed" layers -- inner longitudinal outer circular.
16. distensible sac with transitional epithelium and lamina propria but no muscularis mucosa. muscularis externa thick and chaotic.
17. PSC epithelium, near bladder is more transitional, near exterior is more non keratinzed stratified squamous. muscularis externa has inner longitudinal, outer circular.
Subscribe to:
Posts (Atom)