Term
| External anatomy of the kidneys. |
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Definition
| right lower than left, about 5 in long, located in the retroperotineal space in the lower abdomen. Surrounded by fibrous connective capsule and a protective renal fat pad. |
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Term
| Internal anatomy of kidney - cortex |
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Definition
| superficial layer. Renal columns - where blood flow comes in between pyramids |
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Term
| internal anatomy of kidney - medulla |
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Definition
deeper layer.
renal pyramids - where urine is formed
renal papillae - where urine exits the pyramid and enters minor calyces to major calyx to renal pelvis to ureter |
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Term
| Describe micturition reflex. |
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Definition
| controls urine output. Micturition reflex stimulates internal and external urinary sphincters. Urge to urinate occurs when about 200 ml has collected. If urge ignored, goes away until another 200 ml have collected. |
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Term
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Definition
| exit hilum, run inferiorly and medially to where they enter the bladder. They are narrow muscular tubes lined with transitional epithelium and smooth muscle. Urine forced to bladder by peristalsis. |
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Term
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Definition
in pelvic cavity, posterior to pubic symphysis.
Composed of transitional epithelium surrounded by smooth muscle layer. |
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Term
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Definition
| lined primarily with stratified squamous epithelium. Females: 3-4 cm in length. Males 20 cm in length. |
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Term
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Definition
| visceral layer of Bowman's capsule and have many filtration slits in them |
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Term
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Definition
| composed of Bowman's capsule (glomerular capsule) and Glomerulus. Glomerular capillaries are fenestrated, which allows filtration of blood plasma to occur from the capillaries into the surrounding capsule and proximal convoluted tubule |
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Term
| How is blood supplied and taken away from each glomerulus? |
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Definition
| Each glomerulus has an efferent and afferent arterioles. |
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Term
| Structure of peritubular capillaries. |
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Definition
| arise from efferent arterioles; run close to nephron tubules and collect substances that pass out of nephron. |
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Term
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Definition
| peritubular capillaries found in the deepest parts of the medulla and have different structure than other peritubular capillaries. |
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Term
| What are the juxtaglomerular cells? |
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Definition
| Part of JGA; enlarged smooth muscles cells in walls of arterioles that act as mechanoreceptors and control amount of vasoconstriction of afferent arterioles. |
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Term
| What are the macula densa? |
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Definition
| Part of JGA; cells that act as chemoreceptors and monitor solute concentration of filtrate. |
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Term
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Definition
| cuboidal epithelium, many mitochondria, active transports, numerous microvilli. |
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Term
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Definition
| simple squamous, freely permeable to water |
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Term
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Definition
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Term
| Histology of DCT/CD - cuboidal, fewer microvilli |
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Definition
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Term
| What is the structure of the filtration membrane? |
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Definition
| filtrate is formed when plasma is pushed across the fenestrae of glomerular capillaries into PCT. Barrier is small so things such as small hormones, and minerals can cross but plasma proteins and RBC cannot. |
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Term
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Definition
| hydrostatic pressure pushes fluid across the filtration membrane into the nephron tubules. |
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Term
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Definition
| movement of fluid from filtrate back into blood vessels. |
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Term
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Definition
| movement of wastes from blood vessels into filtrate. |
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Term
| What is renal blood flow? |
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Definition
| about 21% of CO goes to kidneys. RBF = 1176 ml/min. |
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Term
| What is renal plasma flow? |
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Definition
| Of the 21% of RBF there is 55% that is plasma. RPF = 650 ml. |
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Term
| What is Filtration Fraction? |
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Definition
| of the 21%, only 19% is filtered. |
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Term
| What is glomerular Filtration Rate? |
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Definition
| 125 ml produced each minute |
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Term
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Definition
| only about 1% of GFR is turned into urine. UFR = 1.25 ml/min |
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Term
| What is net filtration pressure? |
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Definition
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Term
| Glomerular blood pressure |
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Definition
| forces water and solutes out into the intracapsular space. GP = 55 mmHg |
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Term
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Definition
| The RBC's and plasma proteins in the glomerulus exert a pull on the fluid that is being forced out. COP = 30 mmHg |
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Term
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Definition
| The RBC's and plasma proteins in the glomerulus exert a pull on the fluid that is being forced out. COP = 30 mmHg |
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Term
| Capsular hydrostatic pressure |
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Definition
| push of fluid in the tubule against bowman's capsule. CP = 15 mmHg |
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Term
| Autoregulation of Filtration - afferent |
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Definition
increase in BP causes constriction of afferent, prevents too big an increase in RBF.
decreases in BP: dilation of afferent, prevents too big a decrease in RBF. |
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Term
| Autoregulation of Filtration - efferent |
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Definition
efferent constriction and afferent dilation = increased filtrate formed
efferent dilation and afferent constriction = decreased filtrate formed |
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Term
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Definition
| Is driven by a decrease in blood pressure, activation of macula densa, or sympathetic stimulation. Ang II is powerful vasoconstrictor that raises blood pressure and stimulates aldosterone release from adrenals so that more sodium and water is reabsorbed in kidneys |
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Term
| What does stimulation of the sympathetic nervous system do to renal blood flow and filtrate formation? |
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Definition
| NE can cause extreme vasoconstriction and lead to renal damage. |
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Term
| What is reabsorbed in PCT? |
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Definition
| 65% of filtrate: AA, glucose, NA+, K+, CL-. Transported by cotransport against concentration gradients from the lumen into the surrounding epithelial cells and eventually into peritubular capillaries. |
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Term
| What is reabsorbed in DL? |
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Definition
| 15% filtrate reabsorbed. Water moves out of the bubules by osmosis, solutes like NA+ and urea move into tubule to create equilibrium. |
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Term
| What is reabsorbed in AL? |
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Definition
| impermeable to water. NA+, K+, CL- cotransported into interstitial fluid decreasing concentration of filtrate. |
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Term
| What is reabsorbed in DCT and CD? |
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Definition
| 19% of filtrate. Aldosterone causes Na+ to be actively transported into interstitial fluid and K+ ions to be secreted. Water reabsorbed here. ADH has pronounced effect in CD. |
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Term
| What is tubular secretion? |
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Definition
| can be active or passive transport of substances from the cells into the filtrate. Plays important role in managing pH. |
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