Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Renal > Day 5/18/15 > Flashcards

Day 5/18/15 Flashcards

1
Q

Hypovolemic Hyponatremia

A
  • dec. total body Na and dec total body water also, but to a lesser extent bc of appropriate ADH release
  • hemorrhage
  • plasma volume and EC fluid losses (GI loss, sweating)
  • tx: restore plasma volume by giving normal saline
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Hypervolemic Hyponatremia

A
  • excess total body Na (edema) and even more excess total body water
  • can be due to heart failure, liver cirrhosis, kidney disease
  • effective blood volume is so low that ADH is stimulated and released
  • thiazide diuretics impair dilution and are frequent cause
  • edema, ascites, pleural effusions, weight gain
  • tx: water restriction and loop diuretics and tx of underlying condition (note: do NOT give salt)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Euvolemic Hyponatremia

A
  • syndrome of inappropraite ADH secretion (hypothyroidism, adrenal insufficiency, nausea, pain, psychosis, meds)
  • will have urine that is not maximally diltute
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Sx of Hyponatremia

A
  • depend on speed of development (acute/chronic) and on severity
  • anorexia, nausea, vomiting
  • weakness, lethargy, confusion, seizures, death
  • sx likely due to cerebral edema
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Tx of Euvolemic Hyponatremia

A
  • hypertonic saline for seizures
  • water restriction and correction of underlying disorder
  • ADH antagonists
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Sxs of Hypernatremia

A
  • thirst
  • neuromuscular irritability with twitches, seizures
  • altered mental status
  • failure to thrive in infants
  • high mortality rate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Causes of Hypernatremia

A
  1. renal or extrarent losses that exceed Na loss (hypovolemic hypernatremia)
  2. addition of hypertonic fluid (hypervolemic hypernatremia), usually iatrogenic
  3. lack of ADH effect: diabetes insipidus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Diabetes Insipidus 2 Causes

A
  1. no ADH is secreted

2. kidneys do not respond to ADH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Acquired Nephrogenic Diabetes Insipidus Definition

A

-chronic kidney disease causes a concentrating defect due to tubular dysfunction as well as ADH resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Causes of Acquired Nephrogenic Diabetes Insipidus

A
  • sickle cell anemia and polycystic kidney disease cause early concentrating defects by disrupting medulla
  • urinary obstruction causes ADH resistance
  • pregnancy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Effective Arterial Blood Volume

A

-that amount of arterial blood volume required to adequately “fill” the capacity of arterial circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Components of the Homeostatic Response

A

Afferent Limb- volume receptors:

  • low-pressure baroreceptors
  • high-pressure baroreceptors
  • intrarenal sensors
  • hepatic and central nervous system sensors

Efferent Limb- effector elements:

  • glomerular filtration
  • physical factors at level of proximal tubule
  • humoral effector mechanisms
  • renal sympathetic nerves
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Location of Low Pressure Baroreceptors

A

-venous side of circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Location of High Pressure Baroreceptors

A

-atrial side of circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Renal Autoregulation

A

-an ability of the kidney to keep renal blood flow and GFR constant by the contraction of the vascular smooth muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

TGF

A

-phenomenon whereby increased distal delivery of sodium chloride to the macula densa increases afferent arteriolar tone and returns the RBF and GFR towards normal values

17
Q

Glomerulo-tubular Balance

A

-property of the kidney whereby changes in GFR automatically induce a proportional change in the rate of proximal tubular sodium reabsorption

18
Q

Humoral Effector Mechanisms

Inc. and Dec. Na Reabsorption

A

Inc. Na Reabsorption

  • angiotensin II
  • aldosteron
  • catecholamines
  • vasopressin

Dec. Na Reabsorption

  • natriuretic peptides
  • prostaglandins
  • bradykinin
  • dopamine
19
Q

Function of Renal Sympathetic Nerves

A

} Sympathetic nervous system innervates the afferent and efferent arterioles of the glomerulus

} Activation of these nerves has an anti-natriuretic effect

} Nerve stimulation enhances the release of renin from the JGA

20
Q

Na Reabsorption in Proximal Tubule

A

} The proximal tubule reabsorbs about 60% of the glomerular filtrate, including the sodium
} Sodium reabsorption occurs by both passive and active mechanisms
} Occurs down the electrochemical gradient of sodium
} Gradient is maintained by the action of the sodium pump
(Na/K/ATPase) at the basolateral membrane
} Active mechanism of sodium transport is through the Na/ H antiporter


21
Q

Na Reabsorption in Loop of Henle

A

} About 30% of the filtered sodium is reabsorbed in TALH
} Impermeable to water but highly permeable to sodium
} Tubular fluid: dilute with a low NaCl concentration
} Reabsorption of sodium at the apical membrane occurs by Na/K/2Cl co-transporter, an active transport process

22
Q

Serum Indices of Renal and Extrarenal Volume Contraction (Loss)

A

} Increased BUN: plasma creatinine ratio
} Metabolic alkalosis during upper GI loss of fluid
} Metabolic acidosis during lower GI loss of fluid
} Increased hematocrit and serum albumin because of hemoconcentration

23
Q

Urinary Indices of Volume Contraction (dec.)

A

 Urinary sodium > 20 mEq/L=Renal losses
 Urinary sodium 1.010
 Urine osmolality > 300 mOsm/Kg

24
Q

Tx of Fluid Contraction (Loss)

A

} Objective: is expansion of the ECF volume
} Replacement fluid should resemble the lost fluid
} Rate, amount, and route of replacement will depend on the situation
} Blood, albumin and dextran solutions contain large molecules preferentially expand the intravascular volume
} Isotonic normal saline (which is comprised of 0.9% NaCl or 154 mEq/L of NaCl) preferentially expands the ECF
volume


25
Q

Pathophysiology of Nephrotic Syndrome

A

} Loss of albumin in the urine and hypoalbuminemia
} Fall in the capillary oncotic pressure
} Flux of fluids from the vascular space into the interstitium and a fall in effective arterial blood volume

26
Q

Thiazides

A
  • work in distal tubule
    (1) Inhibit the sodium/chloride transporter
    (2) They increase calcium reabsorption and decrease urinary calcium excretion
27
Q

Carbonic Anhydrase

A
  • work in proximal tubule
    (1) Should be used to mobilize edema
    (2) Improve cardiac and respiratory function
    (3) Excessive use: worsen kidney function
    (4) Several classes of diuretics are available
28
Q

K+ Sparing Diuretics

A
  • works in distal tubule/collecting duct?
    (1) Triamterene and amiloride are sodium channel blockers
    (2) Sspironolactone is a competitive inhibitor of aldosterone
29
Q

Loop Diuretics

A
  • works in thick portion of asc. loop of henle?
    (1) Inhibits the coupled entry of sodium, potassium, and chloride across the apical membrane in TALH (at the Na/2Cl/K co- transporter)
    (2) Metabolic alkalosis, hypokalemia, hypocalcemia, and hypomagnesemia

Renal (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions