Week 3 Flashcards
OPC: What are 1 common dysfunctions of the sacrum?
L on L torsion
OPC: For sacrum, what might you deduce if there is asymmetry at the base but not the ILA?
Means there is more likely a innominent dysfunction than a sacral dysfunction
CPR: How do you calculate filtration fraction?
FF = GFR/RPF
CPR: What is normal FF?
Normal FF is 20%
CRP: What can you use to estimate renal plasma flow? Why?
- Est via PAH
- Since PAH is 100% excreted and largely secreted by the PCT
CPR: What do you use to estimate GFR?
Est. via creatinine clearance
CPR: How to calculate renal clearance?
Cx = (Ux * V) / Px
where X is substance
U is urine concentration substance
V is urine flow rate
P is plasma concentration
CPR: What is Renal clearance
Volume of plasma cleared of a substance in a defined amount of time
CPR: What does Mannitol do to fluid movement in the body?
Mannitol infusion puts lots of solutes into the ECF which drives water out of the ICF into the ECF
CPR: What makes up the basement membrane of the glomerulus?
Type 2 Collagen
CPR: Explain changes to GFR, RPF, and FF change when:
Afferent arteriole constriction
Afferent arteriole constriction:
- GFR decreased
- RPF decrease
- Filtration fraction is unchanged
CPR: Explain changes to GFR, RPF, and FF change when:
Efferent arteriole constriction
Efferent arteriole constriction:
- GFR increased
- RPF decreased
- Filtration fraction increased
CPR: Explain changes to GFR, RPF, and FF change when:
Increased plasma oncotic pressure
Increased plasma oncotic flow:
- GFR: decreased
- RPF: unchanged
- Filtration fraction: decreased
CPR: Explain changes to GFR, RPF, and FF change when:
Decreased plasma oncotic pressure
Decreased plasma oncotic pressure
- GFR: increased
- RPF: Unchanged
- Filtration fraction: increased
CPR: CPR: Explain changes to GFR, RPF, and FF change when:
Increased ureteral constriction
Increased ureteral constriction
- GFR: Decreased
- RPF: no change
- Filtration fraction: decreased
CPR: CPR: Explain changes to GFR, RPF, and FF change when:
Dehydration
Dehydration:
GFR: Decreased
RPF: Decreased?
FF: Increased b/c RPF decreases even more than GFR
CPR: Explain Prostaglandin effects in the kidney
What inhibits prostaglandins?
- Afferent arteriole vasodilation (counteract Ang II)
- NSAIDS are COX inhibitors which can block prostaglandin production allowing too much vasoconstriction
CPR: How to calculate eGFR?
eGFR = U creatinine * V / P creatinine
CPR: How do you calculate RBF?
RBF = RPF/ (1-Hct)
CPR: Where is glucose reabsorbed?
- 100% of glucose is reabsorbed in the Proximal convoluted tubule
CPR: When does Glucose start to saturate _____________ transporters?
SGLT2 transporters saturated when glucose is > 200 mg/min
CPR: Why might pregnant women have glucosuria?
- During pregnancy blood volume increases
- Increase in GFR resulting in increased glucose filtration which can oversaturate SGLT2 transporters so some glucose gets into the urine
- Can occur even when plasma glucose is normal
CPR: What are extrinsic factors contributing to control of GFR?
- Extrinsic = neurohumoral
1. SNS
2. Ang II
3. Prostaglandins
4. Endothelial-derived nitric oxide
5. Endothelin
CPR: What are intrinsic factors contributing to control of GFR?
Intrinsic = local = autoregulation =
1. Myogenic mechanism
2. Macula densa
CPR: Describe the _________________ myogenic mechanism and the effect it exerts on GFR
- B/t 60-160 MAP, the GFR needs to maintain constant renal blood flow
1. Increasing stretch of the blood vessels, the body senses there is increased MAP
2. The stretching activates stretch sensitive Ca+2 receptors on the afferent arterioles = vasoconstriction
1a. Decreased stretch of the blood vessels, the body senses a decrease in MAP
2a. Without stretch, the Ca+2 sensitive receptors are closed and allow the afferent arteriole to dilate
CPR: Describe how the ________________ tubuloglomerular feedback at the macula densa exerts its effect on the GFR when there is increased MAP
- On the DCT, the macula densa senses increased MAP which means increased GFR. Increased GFR means increased NaCl filtered which tells the juxtaglomerular cells proximal to the afferent arteriole to constrict causing afferent arteriole constriction
CPR: Describe how the ________________ tubuloglomerular feedback at the macula densa exerts its effect on the GFR when there is decreased MAP
- On the DCT, the macula densa senses decreased MAP and thus there is decreased GFR meaning there is decreased NaCl filtration. This tells the juxtaglomerular cells to allow the afferent arteriole to vasodilate
CPR: Other than glucose, what is reabsorbed at the PCT?
~ 70%: Na+, Cl-, PO 4 -3 , K+, HCO 3 -
CPR: Where are SGLT2 transporters? What do they do?
- They are cotransporters that move Na+ and glucose from the PCT to the cell
CPR: Describe how HCO 3 - , _________________, moves into the peritubular capillary in the PCT
- Uses bicarbonate buffer system
- CO2 can freely diffuse from the PCT to the cell since it is a gas
- In the cell, carbonic anhydrase converts to CA & H2O and is subsequently transformed into: HCO 3 - & H+
- Lastly, a HCO 3 - /Na+ cotransporter moves these molecules from cell to peritubular capillary
CPR: How does PTH affect reabsorption at the PCT?
- Parathyroid hormone decreases Na+/PO 4 -3 cotransport to peritubular capillary
CPR: Describe what happens at the thick ascending loop of Henle
- Urine dilution due to reabsorption of Na
CPR: Describe how Na is reabsorbed at the Thick ascending loop of Henle
- Na/K+ ATPase active transporters at the peritubular cell side push Na+ out of the cell against its gradient
- On the loop side, K+ channels drive [K+] down its concentration gradient and out of the cell into the thick ascending loop
- This has created a gradient for the NaKCC channels to reabsorb: Na+, 2 Cl-, K+ to come into the cell
CPR: Describe how Mg+2 and Ca+ are reabsorbed in the Thick Ascending loop of Henle
- Both use paracellular movement from the loop to move into the peritubular capillary
CPR: Describe K+ and Cl- reabsorption from the cell into the Peritubular capillary at the Thick Ascending loop of Henle
- High [K+] in the cell
- Increased [Cl-] concentration due to co-transport with Na+ drives both K+ and Cl- to use passive transport down their concentration gradients out of the cell and into the peritubular capillary
CPR: Describe reabsorption at the Thin descending loop of Henle
- Here only permeable to H2O
- This portion of the nephron is very salty which creates a concentration gradient to pull water out of the loop and into the medulla
- Urine concentration occuring here
CPR: What is Bartter syndrome? What happens to the urine and plasma?
- Autosomal recessive disorder
- Defect in the NaKCC channels that disallows reabsorption of Na, K+, Cl- from the renal tubule into the cell
- Causes: metabolic alkalosis, hypercalciuria, hypokalemia
CPR: Describe the gradient that influences movement of Mg+2 and Ca+2 into the peritubular capillary at the thick ascending loop of Henele
- On the apical side of the cell that faces the loop, there is excretion of K+ ions down the concentration gradient that makes the loop + charged overall
- This + charge creates a Mg+2 & Ca+2 concentration gradient to make these + ions want to flow down via paracellular movement to the peritubulular capillary
CPR: Describe the movement of Na+ & Cl- in the Distal convoluted tubule
- Na+ & Cl- use a symporter on the apical side for reabsorption
- On the basal side, uses active transport- Na+/K+ ATPase to move sodium into the peritubular capillary
CPR: Which side is apical and basal of the cells in the nephron
- APICAL SIDE FACES THE LUMEN OF THE TUBULE
- BASAL SIDE FACES THE PERITUBULAR CAPILLARY
CPR: Describe the movement of Mg+2 and Ca+2 at the DCT
- On the apical side, both flow down the concentration gradient using individual transporters for each
- On the basal side, Ca+ is reabsorbed into the peritubular capillary via Ca+ efflux and Na+ influx (Na+ moving with its concentration gradient which is secondary active transport)
CPR: Describe the influence of Parathyroid hormone on the DCT
- In the peritubular capillary, PTH binds to a receptor on the basal side of the DCT
- This causes the Na+/Ca+ channel to increase action and thus drive more Ca+ reabsorption
- Overall goal is to increase Ca+ levels in the body
CPR: What is Gitelman Syndrome? Describe how this changes plasma and urine
- NaCl channel reabsorption problem at the DCT
- Thus there decreased reabsorption of both ions
- Causes: hypocalcuria, hypokalemia, hypomagnesium, & metabolic alkalosis
CPR: Where do thiazide diuretics work? What do they do?
- Exert their effect at the DCT
- Decrease activity of the Na/Cl- cotransporter and thus decrease Na+ reabsorption to decrease water retention
CPR: What is the reflection coefficient?
- Its value is indicative of what is permeable to a membrane
- Represented by σ
- If σ=1, then the membrane is only permeable to water
- IF σ=0, then membrane is permeable to another substance, i.e. Na+, Cl- etc
CPR: What is the osmolarity of a solution with 1 mole of Na+/Cl-? What is the osmolarity of a solution with 1 mole of glucose? Why are they different even tho each is one mole?
1 mole Na+/Cl- is 2 osm/L, 1 mole of glucose is 1 osm/L. B/c Na+ & Cl+ can be broken up in a solution into separate ions while glucose cannot
CPR Lab: What levels of the sympathetic trunk does the greater splanchnic nerve arise from?
Greater splanchnic nerve arises from the sympathetic trunk levels at T5-T9
CPR Lab: What is the most common cause of hemoptysis?
- Source from bronchial artery
CPR: During dehydration, most water will be reabsorbed at the PCT, why?
- Since 70-75% of Na is reabsorbed in the PCT
- Anytime Na is reabsorbed water will follow
CPR: Where in the nephron is Na reabsorption hormonally independent?
Where in the nephron is Na reabsorption based on hormones or outside factors?
- PCT: Sodium reabsorption is always 70-75% at the PCT regardless of hormones present & thus the same amount of water is reabsorbed here too
- DCT: Sodium reabsorption in the DCT is dependent on what hormones are present, i.e. low or high ADH, dehydration, volume overload
CPR: What are juxtaglomerular cells?
What are granular cells?
Where are they found & what do they do?
- Juxtaglomerular cells AKA granular cells are found at the afferent arteriole and are part of the juxtaglomerular feedback mechanism
- These cells secrete renin
CPR: For someone with a juxtaglomerular tumor, what class of drugs would be administered and why?
- ACE Inhibitors
- The tumor will cause increased release of Renin = HTN, so the ACE inhibitors will prevent this
CPR: What cells are the initial start of the tubuloglomerular feedback system?
- Osmoreceptors in the macula densa of the DCT sense flow of NaCl in filtrate
- The macula densa communicates with the glomerulus
- High flow of NaCl in the filtrate will cause GFR to be decreased
- Low flow of NaCl in the filtrate will cause GFR to be increased
CPR: T/F prostaglandins dilate afferent and efferent arterioles of the kidney
True, prostaglandins dilate both Afferent and Efferent arterioles
CPR: What do intercalated cells do in the collecting tubule? Are they also found other places?
- Intercalated cells include β & α cells
- Found both at the DCT and collecting tubule
- α cells activated in metabolic acidosis to secrete H+ & Cl- ions
- β cells activated in metabolic alkalosis to secrete HCO3- & K+
CPR: α cells are more commonly activated, why?
- Metabolic acidosis is more common than metabolic alkalosis
- Since α cells secrete H+ & Cl- ions to the renal tubule and cause Bicarb Reabsorption
CPR: How does dopamine affect renal perfusion?
- Dopamine causes vasodilation & thus can be administered as a protective measure for acute renal failure
CPR: Where are NKCC2 channels found?
What drugs act on them?
- NKCC2 are Na-K+-Cl- symport channels for reabsorption at the thick ascending loop of Henle
- Furosemides inhibit NKCC2 channels from reabsorbing and thus encourage diuresis
CPR: Why are NSAIDS such as Naproxen, _______________, and _____________________ not recommended for patients with renal disturbances?
- Naproxen, Ibuprofen, Idomethacin are all NSAIDS
- NSAIDS inhibit prostaglanding production & thus can place patient at risk for renal injury due to increased pressure
CPR: Explain how Furosemide works
- Furosemide is a loop diuretic that works by inhibiting NKCC2 symporters at the ascending loop of Henle
- Stimulate prostaglandin release & thus has a vasodilatory effect
- Vasodilation increases renal blood flow that leads to increased GFR and enhanced drug delivery
CPR: What does Endothelin do?
- A peptide hormone found in smooth muscles that causes contraction
-Potent vasoconstrictor
CPR: T/F: Loop diuretics stimulate renin release
True, since loop diuretics have vasodilatory effects, the increased RPF will induce tubuloglomerular feedback and initiate renin release
CPR: What does Aldosterone do?
Where does it come from?
- Aldosterone is secreted by the adrenal cortex
- Aldosterone stimulates K+ secretion by the principal cells of the collecting tubules
CPR: What does spironolactone do? Where does it exert its effects?
- Is a aldosterone antagonist
- Thus it works at the DCT & Collecting duct
- Is a diuretic via inhibiting the action of aldosterone and reducing the amount of Na reabsorption
CPR: What do Naturetic peptides do?
- Naturetic peptides include atrial Naturetic peptide and BNP (from ventricle) that cause vasodilation, natriuresis and diuresis in response to volume expansion
CPR: Describe how sympathetic activation impacts renal hemodynamics
- SNS activation causes vasoconstriction of afferent arteriole and stimulates renin release & its cascade
- vasoconstriction of afferent arteriole causes decreased RPF thus decreasing glomerular capillary hydrostatic pressure thus decreasing GFR overall reducing net filtration pressure
- Peritubular capillary hydrostatic pressure decreases and thus peritubular capillary oncotic pressure is stronger favoring increased peritubular reabsorption and secretion of NaCl
CPR: What does Tm mean?
Tm = reabsorption
CPR: How to calculate Tm?
Tm/Reabsorption = Filtration - Excretion
Tm = (GFR X Pc) - (Uflow -Uconc)
GFR: In normal kidneys, which of the following is true of the osmolarity of renal tubular fluid that flows through the early distal tubule in the region of the macula densa?
Hypotonic compared with plasma
CPR: What is the major determinant of GFR regarding hydrostatic and osmotic pressures?
The major determinant of GFR is glomerular capillary hydrostatic pressure
CPR: Ang II causes constriction of both afferent and efferent arteriole, most significant constriction occurring:
Ang II causes constriction of efferent arteriole and increases hydrostatic capillary pressure & GFR
CPR: What are the repercussions of ureterblockage?
Increasing Bowman’s capsule pressure and opposing filtration, thus decreasing GFR
CPR: Why is colloid osmotic pressure in Bowman’s capsule not considered the opposing force to glomerular capillary hydrostatic pressure in healthy individuals?
In healthy individuals, protein should not be filtered through the glomerulus
- Thus colloid osmotic pressure in Bowman’s capsule should be 0 & therefore cannot be an opposing force
- Thus the opposing force to glomerular filtration is plasma osmotic pressure
CPR: What substances might be found in glomerular filtrate?
- Small molecular substances
- Ions
- Glucose
- Amino acids
- Urea
CPR: How to calculate Net filtration pressure of the glomerulus?
NFP = (Out + out) - ( In + in)
NFP = (Hydrostatic P capillary + Oncotic P Bowman’s ) - (Oncotic P capillary + Hydrostatic P Bowmans )
- note, Oncotic pressure in healthy individuals should be 0
CPR: Explain how GFR and filtration fraction are changed when the efferent arteriole is vasoconstricted
- RPF decreases
- But GFR increases since there is increases resistance = increased hydrostatic pressure in the glomerular capillary
- Filtration Fraction = GFR / RPF
- FF gets larger since the ratio is becoming larger
CPR: What happens to filtration fraction when the afferent arteriole is vasoconstricted and efferent arteriole unchanged?
- Filtration fraction does not change b/c both GFR and RPF are decreased and thus the ratio is the same
- FF = GFR/RPF
CPR: A researcher in a laboratory wants to use an agent that will cause simultaneous constriction of the afferent and efferent arterioles in the kidney and therefore decrease both the renal blood flow and glomerular filtration rate. What mechanism/substance is the best choice for induction?
- Norepinephrine
CPR: Why is the osmolarity of renal tubule fluid that flows through the early distal tubule hypotonic?
- As filtrate flows up the ascending loop of Henle the solutes are reabsorbed
- Since this portion is impermeable to water, overall dilution of the filtrate is occurring
- So in the early DCT, this portion is considered the diluting segment of the renal tubule
CPR: What is the osmolarity of filtrate when it reaches the early distal tubule?
100 mOsm/L
CPR: What tends to decrease potassium secretion by the cortical collecting duct?
- A diuretic that inhibits the action of aldosterone, i.e. spironolactone
- Blockade of the action of aldosterone with spironolactone inhibits potassium secretion
CPR: When GFR decreases by 50%, what substance would be found to have increased the greatest in plasma concentration and why?
- Normally, creatinine is filtered at the glomerulus
- It is not secreted or reabsorbed and nearly entirely excreted and, thus is an indicator of eGFR
- If GFR decreases, then less is being filtered, thus less creatinine is being sent to the nephron loops and stays in the plasma
CPR: Why does metabolic acidosis decrease intracellular K+ concentration and K+ secretion in the collecting duct?
- Increased H+ concentration inhibits potassium secretion by reducing the activity of the Na/K+ ATPase pump in the principle cells
- Thus less K+ is less K+ is moved into the cell
- Thus there is less K+ in the cell to passively diffuse across the luminal membrane into the collection tubule
CPR: Where is the majority of K+ secreted?
- K+ secreted in the late DCT & collecting tubule
CPR: Describe the movement of PAH through the tubules
- At the GFR, PAH filters freely through
- However, the largest contribution of PAH to the filtrate comes from secretion by the proximal tubule
- No reabsorption
- Indicator of renal plasma flow
CPR: Describe how increased ADH induces aquaporin insertion at the ___________________________.
- ADH is secreted from the posterior pituitary gland
- Causes insertion of aquaporins at the apical principle cell of the collecting duct
- V2 receptors in principle cells stimulated > G s insertion of endosomes containing aquaporin 2
GFR: If PAH secretion is blocked, why is the clearance considered equal to the GFR?
- PAH contribution comes largely from PCT secretion
- If PAH secretion is blocked, then the only contribution of PAH is from the filtrate and urine is from glomerular filtration & thus would match GFR
CPR: What does + Free Water clearance mean?
- Dilute urine is being formed
- Too much H20 is being secreted
CPR: What does - Free Water clearance mean?
- Excess solutes are removed from the blood and water being reserved
- Concentrated urine
CPR: What is Free Water clearance?
Comparing Urine osmolarity / Plasma osmolarity
CPR: What does it mean if a substance appears in the renal artery but not in the renal vein?
- The substance is not filtered
- Entirely secreted by the peritubular capillaries
- Clearance is equal to the renal plasma flow
CPR: What are the normal values for human pH?
7.4 +/- 0.5
7.35 - 7.45
CPR: What is the normal value [CO2]?
1.3 mM
CPR: What is the normal value of P CO2?
40 mmHg in the arterial
CPR: What is the normal value of [HCO3]?
24 mM
CPR Lab: What does I 8 10 EGGS AAT 12 mean?
Diaphragm openings
- I 8: Inferior vena cava found at the level of T8
- 10 Eggs: Esophagus found at level of T10 & CN 10
- AAT 12: Azygos vein, ascending aorta, thoracic duct found at level of T12
CPR Lab: What is ligamentous arteriosum a remnant of?
Ductus arteriosus
CPR Lab: What does the phrenic nerve innervate?
Diaphragm
CPR Lab: What level of the the sympathetic trunk does the greater splanchnic nerve arise?
The greater splanchnic nerve arises from the sympathetic trunk at levels T5-T9
CPR Lab: What does the innermost intercostal nerve innervate?
Intercostal nerves
CPR Lab 4: Name the nerve, artery, vein found in the posterior mediastinum
In order from superior to inferior most
- Nerve: Intercostal nerve
- Artery: Posterior intercostal A.
- Vein: Posterior intercostal V.
CPR Lab: List the impressions for visceral organs on their posterior surface of the L lung?
- L lung: Descending aorta impression & arch of aorta
CPR Lab: Name the fissures of each lung & what lobe they separate
- L: Oblique fissure separates the superior and inferior lobe
- R: Oblique fissure separates the inferior and middle lobe
- R: Horizontal fissure separates the superior and middle lobe
CPR Lab: List the impressions on the posterior surface of the R lung:
CASE
C: Cardiac notch
A: Arch Azygos vein
S: Superior vena cava
E: Esophageal
CPR Lab: What is on the R lung that if ruptured is a common cause of hemoptysis?
Brachial Artery of the R lung common cause of hemoptysis
CPR Lab: list the structures on the Arch of Aorta to know:
- Brachiocephalic trunk > gives rise to R common carotid and subclavian
- Left common carotid
- Left subclavian
CPR Lab: What structure is proximal to the L recurrent larygneal N?
The L recurrent laryngeal nerve travels under the ligamentum arteriosum to reach the vocal cords
CPR Lab: List the branches of the SVC need to know
- R & L brachiocephalic veins come off the SVC
- They travel under the arch of aorta
CPR Lab: What is the carina?
The point of the main bronchus divides into L & R secondary/lobar bronchi
CPR Lab: On the L side of the mediastinum, what two structures associated with the Azygos vein are found?
- Ascending is the Accessory Hemiazygos vein
- Descending branch is the Hemiazygos vein
CPR Lab: What is the Pulmonary ligament and where is it found?
- Found on both lungs proximal to the hilum
- Where the visceral and parietal pleura meet
CPR Lab: What is important to remember about the costodiaphragmatic recess? Where is it found?
- Found more laterally
- The costodiaphragmatic recess is a narrow space in the pleural cavity where the costal and diaphragmatic pleura meet
- On XR needs to have sharp points, if there are rounded points here it is an indication of pleural effusion
CPR Lab: what are the muscles found on the posterior rib cage in the mediastinum?
Innermost intercostal M.
CPR: What type of water movement is occurring in burns, diarrhea, hemorrhage?
- Iso-osmotic volume contraction
- Loss of both solutes and water
CPR: What type of water shift is occurring in severe dehydration (pathological caused by: __________) , alcoholism or water deprivation
- Severe dehydration can be caused by low ADH and so too much water is excreted
- There is hyperosmotic volume contraction