Urinary Flashcards

Question

Filtration coefficient: Surface area (SA)

Answer 1

-Lower surface area ➡️lower GFR ➡️ -Larger SA ➡️greater GFR -Clinical Correlate • Certain conditions can change or affect the SA • Diabetic Nephropathy o Proteins and deposits that make the glomeruli thicker, lessening the SA, and lowering the GFR

Answer 2

-Lesser channels, lower GFR -More channels, higher GFR -Clinical Correlate: Glomerulonephritis • Makes basement membrane very porous ➡️higher GFR ➡️lose more proteins

Answer 3

Volume of particles per kg of solvent (mol/kg) -in glomerulus: blood is 300mosm/L (comes into PCT at 300mosm/L) -mosm= milliosmoles (Note: osmolarity= mol/L Kg=L)

Answer 4

-Blood➡️ kidney tubule -active process: requires ATP

Answer 5

-kidney tubule➡️ blood -depending on chemicals being reabsorbed, it could be active or passive

Answer 6

Pumps 3 Na+ out of cell and 2K+ into cell -move against their concentration gradients from areas of ⬇️ to ⬆️ concentration -location: basolateral -primary active transport: requires ATP -97% of K+ is inside the cell -⬇️[Na+] and ⬆️[K+] -inside cell

Answer 7

-Passive diffusion of one substance helps facilitate the active transport of another substance -Can transport two things at once inside the cell

Answer 8

1)Na+/ glucose contransporter 2) Na+/ AA contransporter 3) Na+/ lactate contransporter

Answer 9

-secondary active transport -location: applical membrane -Na+: ⬇️Na+ inside cell➡️ moving passively along its concentration gradient -Glucose: -⬆️Glucose inside cell Na+ helps move Glucose against its concentration gradient -when inside cell: there are specific transporters on basolateral membrane that transport Glucose out of cell and into bloodstream (tubular reabsorption) -same mechanism w/ Na+/AA cotransporter and Na+/lactate cotransporter -100% glucose, AA, and lactate reabsorbed

Answer 10

CO2 + H2O ➡️ H2CO3 ➡️ H+ + HCO3– -This reaction is catalyzed by the enzyme carbonic anhydrase -Carbon Dioxide (CO2) -Can be found in our blood -Can move into the cell (through basolateral membrane) and react with water to form sodium bicarbonate -Sodium Bicarbonate (H2CO3) -Unstable; dissociates into a proton (H+) and bicarbonate (HCO3–)

Answer 11

-Sodium-Hydrogen Antiporter • Secondary Active Transport • As Na+ moves through the channel to go in the cell, it helps push H+ out -H+ combines with HCO3– outside of the cell • Resulting H2CO3 is converted by carbonic anhydrase into CO2 and H2O

Answer 12

90% HCO3- gets pushed into blood

Answer 13

-obligatory water reabsorption- H2O feels obliged to follow Na+ -H2O moves by osmosis -kidney tubules➡️ blood (reabsorption) -65% of Na+ reabsorbed➡️ 65% of water reabsorbed

Answer 14

-How ions move in between the cell to the blood -Ca2+, Mg2+, K+, Cl– -Very little calcium and magnesium are reabsorbed in this area -About 50% of Cl– is reabsorbed via this -mechanism About 55% of K+ is reabsorbed via this mechanism

Answer 15

Moves Na+ and Cl- into cell -aplical membrane - they are then pushed into the blood (reabsorption)

Answer 16

-lipid-soluble substances can pass through the phospholipid bilayer -E.g., Urea -Not all of it gets reabsorbed -Can pass through the membrane and into the blood

Answer 17

Insulin and Hb -There are specific protein receptors on the membrane -If these small proteins are filtered, they can get caught on these receptors -proteins are endocytosed and taken into the cell -These are combined inside the cell with lysozymes • Hydrolytic enzymes • Break down the proteins into their constituent amino acids -Receptors are recycled -The vesicle fuses with the cell membrane and amino acids are released into the blood

Answer 18

Channel normally brings both Na+ and HPO42– in -There’s a receptor for the PTH on the cell of the proximal convoluted tubule -PTH: Para-Thyroid Hormone • Binds with the receptor and activates the G- stimulatory protein • G-stimulatory protein activates adenylate cyclase • Adenylate cyclase converts ATP ➡️cAMP o cAMP ➡️Protein Kinase A -Protein Kinase A • Puts phosphates on the transporter -Transporter is inhibited • Phosphates don’t get reabsorbed; they get excreted

Answer 19

-Glutamine oSpecific type of amino acid o Can undergo deamination(remove amine group and acidify) -Has two amine groups • After the two amine groups are removed, glutamine is acidified too -Results into 2 ammonium ions -Oxidized into 2 bicarbonate ions • Remove electrons/hydrogen -Normal blood pH is 7.35-7.45 -In metabolic acidosis o Blood pH is low ( < 7.35) o Body has to compensate for that -Bicarbonate from the glutamine will be taken into the blood • Bring the pH back up -Chloride ion will need to go out of the blood into the cell -The ammonium ions will be pushed out of the cell and into the kidney • Will dissociate into ammonia (NH3) and H+ Recap: CO2 + H2O  H2CO3  H+ + HCO3– o When bicarbonate goes out of the cell and into the bloodstream, it makes the pH go up.

Answer 20

In the blood, there are certain things we can’t get rid of. -Because it got reabsorbed, or we can’t filter it -E.g., certain drugs (penicillin, cephalous porins, methotrexate) -Similar with uric acid, bile salts, morphine, organic acids -The process of getting these excreted into the kidney tubules is an active process -Requires ATP

Answer 21

1)Renal corpuscle - Glomerulus -Bowman’s Capsule -Process: Glomerular Filtration 2)Proximal Convoluted Tubule -Processes • Tubular Secretion • Tubular Reabsorption 3)Loop of Henle 4)Distal Convoluted Tubule

Answer 22

⬆️osmolality ⬆️solutes (in blood) ⬇️H2O (in blood)

Answer 23

⬇️osmolality ⬇️solutes (in blood) ⬆️H2O (in blood)

Answer 24

Solutes= H2O

Answer 25

-inside the glomerulus: ~300 mosm o blood plasma -In Bowman’s capsule: ~300 mosm o Isotonic with the blood plasma -When it leaves the PCT: 300 mosm o Still isotonic with the blood plasma o It didn’t change because equal amounts of solutes and water were being reabsorbed -Due to obligatory water reabsorption o Isotonic with the blood plasma -Medullary interstitial osmolality gets saltier or more hypertonic as we go down the renal medulla

Answer 26

Na+/K+/2Cl– Cotransporter o Transports sodium, chloride, and potassium from lumen of filtrate into tubule cell of ascending limb o There are specific channels for each ion in the cell -Na+ and Cl– will be pushed out • Increases osmolality (saltier) -Only some of the K+ leaks out, some of the K+ stays out • Some K+ gets pushed back in the lumen o Creates depolarization of the inner side of the membrane of the ascending limb -Causes Mg2+ and Ca2+ to undergo paracellular transport Descending limb: impermeable to solute

Answer 27

-water will flow out to the area where the salt is -from D. Limb➡️ A. Limb -due to obligatory water reabsorption -via aquaporins -medullary interstitial space: space as we go down ➡️ more water will leave as we go down D. Limb -1200mosm at turn: hypertonic -goes up A. Limb: ⬇️osmolality b/c A. limb is losing salt -120-200mosm when it hits DCT (hypotonic)

Answer 28

-Peritubular capillary in the medulla -Branch of the Efferent Arteriole -Known as the “Counter-Current Exchanger” Blood flow to vasa recta is really slow

Answer 29

1)Prevents rapid removal of sodium chloride -Does not develop the medullary interstitial gradient or the counter-current multiplier mechanism -It’s maintaining the gradient; not generating it 2)Carries Oxygen -Cells depend on oxygen -Vasa recta also delivers oxygen and nutrients

Answer 30

Reabsorption

Answer 31

-H2O permeable -solute impermeable -aquaporin-1

Answer 32

-H20 impermeable -solute permeable -Na+/K+/Cl- cotransporter -pushes these solutes out into medullary interstitum (salty, high osmolality) -some K+ gets pushed back in the lumen, creating a depolarization on inner side of membrane of A. Limb -causes Mg2+ and Ca2+ to undergo paracellular transport

Answer 33

o In the PCT -65% of water was reabsorbed -65% of sodium was reabsorbed -300 mosm o In the descending limb, -15% of water was absorbed o Going into Distal Convoluted Tubule (DCT), -There’s only ~20% water left -There’s only ~10% sodium left (25% of sodium was reabsorbed in the thick ascending limb of the loop of Henle) -100-200 mosm

Answer 34

-specialized channel in basolateral -requires ATP -pumps 3Na+ out and 2 K+ in

Answer 35

Release more urine than normal

Answer 36

-specialized transporters, aplical -Na+: going out of cell via Na+/K+ pump: DCT has ⬆️[Na+] -going along its concentration gradient -only 5-6% of Na+ is being reabsorbed -4-5% left -Cl- has a special channel that pumps it into blood -➖ by thiazide

Answer 37

-diruetic -➖Na+/Cl- symporter -affect salt and water reabsorption -instead of reabsorbing 5-6% back, you’ll lose them in urine -lose a bit of BV (Diuresis)

Answer 38

-➕PTH release -PTH has receptor on DCT -➕2nd messenger system: protein kinase A -protein kinase A ➕ Ca2+ modulated channels -channels pull Ca2+ into cell -channels sensitive to PTH levels -even if ⬇️Ca2+ in blood, there’s still less Ca2+ inside cell -Ca2+ will move against its concentration gradient

Answer 39

-generally impermeable to water -has specialized cells responsible for responding to aldosterone

Answer 40

Steroid hormone produced in top part of (globular cells) of adrenal gland -able to pass through lipid bi layer b/c it is a steroid hormone

Answer 41

1)angiotensin-2: wants to ⬆️BP 2)hyponatremia: ⬇️[Na+] in blood 3)hyperkalemia: ⬆️[K+] in blood

Answer 42

1)Na+/K+ transporter -basolateral -active transport -3Na+ out 2K+ in -Na+ leaves ➡️⬇️[Na+] inside cell -K+ enters ➡️⬆️[K+] 2)Na+ channels -aplical -Na+ is allowed to go inside due to effects of Na+/K+ transporter 3)K+ channels -aplical -⬆️[K+] in cell, channel will move it out of cell where it will eventually be excreted into urine

Answer 43

-presence of ADH will open aquaporins -water will have to follow salt into cell -⬆️H2O volume getting pulled into blood➡️⬆️BP

Answer 44

K+ and HCO3-; hydrogen

Answer 45

Late DCT and CD

Answer 46

Responds to acidosis -respiratory acidosis -metabolic acidosis

Answer 47

⬆️CO2 in the blood -acidosis: ⬇️pH = ⬆️H+ o CO2 -Found in our blood; moves into the cell, and combines with water to form H2CO3 -Catalyzed by enzyme carbonic anhydrase o Sodium Bicarbonate (H2CO3): Unstable; dissociates into proton and HCO3 o Protons (H+) -H-K-ATPase -Both ions are moving against their concentration gradients • K+ goes into the cell • H+ goes out of the cell -Body needs to secrete substances it doesn’t like • Ammonia (NH3): Can be excreted out into the urine where it combines with the protons to produce ammonium (NH4 +) o Bicarbonate (HCO3–): Can be pumped out of the cell into the blood via the HCO3–/Cl– transporter -➡️⬆️pH b/c HCO3- will eventually tie up H+

Answer 48

Respond to alkalosis -respiratory alkalosis -metabolic alkalosis

Answer 49

-The same pathway as intercalated-A cell, but flipped. o Get rid of bicarbonate instead of the proton o Reabsorb proton into the blood instead of bicarbonate -⬆️pH, ⬇️H+, ⬆️HCO3 o Carbon Dioxide (CO2) -Found in our blood; moves into the cell, and combines with water to form H2CO3 -Catalyzed by enzyme carbonic anhydrase o Sodium Bicarbonate (H2CO3) - Unstable; dissociates into proton and HCO3 o Bicarbonate (HCO3 –) -HCO3–/Cl– transporter • HCO3– goes out of the cell o pumped out of the cell into the urine • Cl– goes into the cell o Cl– will exit the cell via the chloride channels on the basolateral membrane o Protons (H+) -H-K-ATPase • ATP-dependent pathway o Both ions are moving against their concentration gradients • K+ goes into the cell • H+ goes out of the cell into the blood -➡️⬇️pH

Answer 50

-Cells that maintain mineral and water balance -Hypothalamus o Collection of neurons from the supraoptic nucleus o Axons move through from the hypothalamus to the posterior pituitary o When stimulated, it will release ADH

Answer 51

-H+ -creatinine -HCO3- -drugs -toxins -NH3

Answer 52

Late DCT and CD

Answer 53

1) High plasma osmolality o ADH wants to have more water in the blood, which means that the plasma osmolality was initially high 2) Angiotensin-II o To increase blood pressure

Answer 54

-ADH binds to the vasopressin receptor (on the principal cell) in the collecting duct of the kidneys, o Will activate the secondary messenger system -cAMP activates Protein Kinase A -phosphorylates proteins on vescicles -pre-synthesized vescicles with proteins and channels (aquaporins) -Activates aquaporin-II -Fuses with the cell membrane -There’s aquaporin-III and aquaporin-IV in the basolateral membrane -Water goes out aquaporin-II, then passes through aquaporins III & IV ➡️ goes into the blood➡️⬆️ blood volume➡️⬆️blood pressure o Also reaches normal plasma osmolality ➡️isotonic

Answer 55

Dependent on presence of PTH

Answer 56

-65% reabsorbed in PCT -15% reabsorbed in D. Limb of loop of henle -20% reabsorbed in DCT -dependent on aquaporin-2, which is dependent on ADH -⬆️ADH➡️⬆️H2O reabsorption -⬇️ADH➡️⬇️H2O reabsorption

Answer 57

-65% reabsorbed in PCT -25% reabsorbed in A. Limb of loop of henle -5-6% reabsorbed in early DCT -remaining 4-5% is reabsorbed depending on presence of aldosterone

Answer 58

Region of nephron where DCT and A Arteriole come in contact to regulate filtration rate

Answer 59

Cell membrane oriented away from lumen of nephron

Answer 60

Cell membrane oriented towards lumen of nephron

Answer 61

-wrap around arterioles of glomerulus -cells of bowman’s capsule -type of epithelial cell

Answer 62

Peritubular capillary network present within the deep part of the medulla -Known as the “Counter-Current Exchanger” -As the ascending limb goes up, it pumps the solutes out ➡️pulling water out of the descending limb o Solutes: Mg2+, Ca2+, K+, Cl–, Na+ -Vasa Recta gets saltier as we go down o due to the Counter-Current Multiplier Mechanism o Water wants to flow out towards where it’s salty o NaCl is pulled into the Vasa Recta -Processes reverses when vasa recta turns and goes up o Water now wants to go back inside o NaCl is being pushed back inside as we go up

Answer 63

1)Prevents rapid removal of sodium chloride -When blood enters, it’s 300 mosm -When blood leaves, it’s 325 mosm • This implies that the vasa recta kept a bit of -NaCl with it to prevent rapid removal 2) Carries Oxygen -Cells depend on oxygen -Vasa recta also delivers oxygen and nutrients

Answer 64

A lot of urea gets lost in the urine, but some are recycled -Urea gets reabsorbed in the last part of the collecting duct o after all the water has been reabsorbed, [urea] starts increasing -It then moves out of the collecting duct and into the medullary interstitium via facilitated diffusion o It gets reabsorbed in the ascending limb of Loop of Henle o At the same time, urea accumulates outside

Answer 65

1) makes concentrated urine 2) contributes to medullary gradient- helps to make medulla more salty

Answer 66

Ability of the kidney to modify BF and urine output How? 1) intrinsic mechanism -myogenic mechanism -tubuloglomerular feedback 2) extrinsic mechanism -SNS -RAAS

Answer 67

Intrinsic -Myogenic = muscle of afferent arteriole -Blood pressure is a surrogate of the glomerular hydrostatic pressure o Glomerular hydrostatic pressure (GHP): pressure inside the capillaries exerted to push substances out of the capillaries and into the Bowman’s capsule

Answer 68

⬆️BP → ⬆️GHP → ⬆️GFR -counter acted by vasoconstriction of AA -Higher glomerular filtration rate (GFR)= more urine -Kidneys modulate the GFR so that it is not too excessive making too much urine, or the blood pressure does not remain too high causing injury on the glomerular capillaries (i) Mechanism: -Blood flows through the AA then to the EA -↑BP = more blood to the AA o Na channels in the smooth muscle is sensitive to stretch: inside of of smooth muscle becomes very (+)➡️ Ca2+ is unloaded into smooth muscle cell➡️vascocontracts -AA vasoconstricts → ↓glomerular blood flow (GBF) →↓filtered plasma and other substance (↓GFR)

Answer 69

↓BP → ↓GHP → ↓GFR -↓BP = ↓urine = can cause kidney injury -How does the kidney prevent it? (i) Mechanism: -↓BP = ↓blood to the AA = ↓stretch on the AA -↓stretch → ↓Na+ enter in the smooth muscle cell → less positive charge → ↓Ca2+ released by the sarcoplasmic reticulum → ↓contraction = relaxation -vasodilation

Answer 70

-intrinsic -this mechanism is sensitive to NaCl -NaCl gets reabsorbed in PCT

Answer 71

↑BP = ↑GFR = ↑NaCl excretion into the kidney tubules -When NaCl transporters in the PCT are saturated, NaCl can escape and move to the LH and then to the DCT where macula densa cells are found o Special NaCl sensors o Release adenosine when it detects ↑NaCl -Adenosine functions to: (1 vasoconstrict AA → ↓GBF → ↓GFR → ↓NaCl being filtered (2 inhibit juxtaglomerular (JG) cells → ↓renin →↓blood pressure

Answer 72

↓BP = ↓GFR = ↓NaCl excretion into the kidney tubules -When macula densa cells detect ↓NaCl in DCT, they release PGI2 and nitric oxide (NO) -PGI2 and NO function to: (1) vasodilate the AA → ↑GBF → ↑GFR → ↑NaCl filtered

Answer 73

Kicks in when BP is relatively low

Answer 74

Stimulus: ↓↓↓SBP → MAP < 65 mmHg o MAP (mean arterial pressure): measure of perfusion o When MAP < 65 mmHg, kidney is not perfused; blood flow is redirected to other “more important” organs such as the heart, brain and muscles

Answer 75

-↓BP triggers baroreceptors → CN IX and CN X send ↓signals to the medulla -Medulla activates sympathetic nerve fibers in the thoracic part causing release of NE and epinephrine

Answer 76

-NE and epinephrine act on the nodal system → ↑HR, ↑SV (due to ↑contractility) → ↑CO → ↑BP o To increase blood flow in the kidneys to avoid injury -NE and epi stimulate the β1 receptors in the nodal system and contractile fibers → ↑HR and ↑SV, respectively o Chronotropic: change in heart rate o Ionotropic: change in contractility

Answer 77

SNS release NE and EPI that act on the α1 receptors of the AA and EA → vasoconstriction → ↓GBF → ↓GFR

Answer 78

NE and EPI act on the α1 receptors on the systemic vessels → vasoconstriction of multiple vessels →↑systemic vascular resistance (SVR) → ↑BP

Answer 79

NE and EPI stimulate the β1 receptors on the JG cells → ↑renin → activates angiotensin II →→→ ↑BP

Answer 80

1) Increase HR and SV 2) Vasoconstriction of the afferent and efferent arterioles 3) Vasoconstriction of the systemic vessels → ↑SVR 4) Triggers release of renin

Answer 81

↓BP → ↓GFR -Juxtoglomerular cells are sensitive to changes in blood pressure o When BP is low, JG cells release renin -Renin cleaves angiotensinogen to produce angiotensin I -Angiotensin I move to the capillaries in the lungs and get converted to angiotensin II by angiotensin converting enzyme (ACE)

Answer 82

1) ADH release -angiotensin 2 ➕ hypothalamus that triggers release of ADH from pituitary -ADH -acts on aquaporin on CD to reabsorb water -⬆️H2O in blood➡️⬆️BV➡️⬆️BP 2) thirst -makes you thirsty➡️ ⬆️water intake➡️⬆️BV➡️BP 3) aldosterone release -angiotensin 2 ➕ release of aldosterone from adrenal gland -function: act on DCT to make them permeable to water and Na+ ⬆️Na+ and ⬆️H2O ➡️⬆️BV and ⬆️BP 4) vasoconstriction of EA and ⬆️GFR -angiotensin 2 binds on the receptor on the EA➡️ vasoconstriction -less blood can escape from glomerulus, more blood stays in glomerulus➡️ more blood filtered out➡️⬆️GFR -angiotensin 2 acts on PCT to cause ⬆️reabsorption of Na+ and H2O -⬆️Na+ and ⬆️H2O➡️⬆️BV➡️⬆️BP 5) vasoconstriction of systemic blood vessels -angiotensin 2 acts on systemic blood vessels➡️ potent vasoconstriction ➡️⬆️SV➡️⬆️BP➡️⬆️GFR

Answer 83

Released from the heart in cases of ↑BP Function: can block any function of the angiotensin II 1)Blocks ADH release = no water and Na+ reabsorption = urinate water and Na+ = ↓blood volume 2) Blocks aldosterone release = no water and Na+reabsorption = urinate water and Na+ = ↓blood volume 3) prevents vasoconstriction= ⬇️GFR 4) vasodilation of blood vessels =⬇️SVR➡️⬇️BP

Answer 84

Promotes Na+/Cl- loss in DCT

Answer 85

Interfere with Na+/Cl- pumps in loop of henle

Answer 86

Low urine volume 50-500ml a day

Answer 87

Little to no volume of urine 0-50ml/day

Answer 88

High urine volume- well over 2000ml a day

Answer 89

UTI- inflammation of the bladder

Answer 90

GFR <60ml/min for 3 mo -Diabetes mellitus -hypertension

Answer 91

GFR < 15ml/min Causes uremia – ionic and hormonal imbalances; metabolic abnormalities; toxic molecule accumulation

Answer 92

Bacterial infection that causes inflammation of renal pelvis or mucous membrane of kidney’s pelvis

Urinary Flashcards

(119 cards)