Exam 6 Flashcards

1
Q

Lipids are

A

Fatty acids linked to the backbone of glycerol and phospholipids by an ester bond, albumin bound

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

Lipid composition

A

Hydrocarbon chains of various lengths and carboxylic acid chain

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

Lipid classifications

A

Saturated or unsaturated, monounsaturated or polyunsaturated, cis or trans configuration

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

triglycerides

A

Contains 3 fatty acid molecules attached to 1 molecule of glycerol by ester bonds

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

Triglycerides containing saturated fatty acids

A

Solid at room temp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

triglycerides containing unsaturated fatty acids

A

Form oils at room temp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Triglycerides from plants

A

Rich in polyunsaturated fatty acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Triglycerides from animals

A

Mostly saturated fatty acids

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

Phospholipids

A

2 esterized fatty acids and a hydrophilic phospholipid head group attached by ester bonds, amphipathic

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

Most common phospholipid

A

Phosphatidylcholine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Cholesterol

A

Unsaturated steroid alcohol with 4 rings and C-H side chain, amphipathic liquid found on surface of lipid layers with phospholipids

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

Cholesterol converted to

A

Primary bile in liver, various hormones, 7-dehydrocholestrol in skin from the sunlight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Cholesterol as fuel

A

Cannot be used as fuel since it cannot be catabolized by most cells

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

Esterified form of cholesterol

A

Cholesteryl ester in which the OH group is conjugated by an ester bond to a fatty acid

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

Lipoproteins structure

A

Consist of lipids and proteins with amphipathic cholesterol and phospholipid on surface, hydrophobic, neutral triglyceride and cholesteryl ester in core

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

Chylomicron

A

Largest in size, lowest in density due to high lipid to protein ratio, highest amount of triacyclglycerols, cause turbidity of postprandial plasma, on top of stored plasma forming creamy layer, deliver dietary lipids to hepatic and peripheral cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

VLDL

A

very low density lipoprotein, 2nd highest in triacyclglycerols, major carriers of endogenous triglycerides and transport triglycerides from liver to peripheral tissues, cause most turbidity in plasma, no creamy layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

IDL

A

intermediate density lipoprotein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

LDL

A

low density lipoprotein, highest in cholesteryl esters, can infiltrate extracellular space, oxidized and taken up by macrophages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

HDL

A

high density lipoprotein due to high protein to lipid ratio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Apolipoproteins

A

Located on surface of lipoproteins, serve as ligands for cell receptors and as activators/inhibitors of different enzymes that regulate lipoprotein particles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Apolipoprotein A-1

A

Major protein on HDL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Apolipoprotein B

A

Principle protein on LDL, VLDL and chylomicrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Apo B-100

A

Found on LDL and VLDL, a ligand for the LDL receptor and linked to lipoprotein (a)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Apo B-48

A

found in chylomicrons, produced by posttranscriptional editing of the apo B-100 mRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Apo C-I, C-II, and C-III

A

On chylomicrons, VLDL and HDL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Apo E

A

on many types of lipoproteins, functions as ligand for LDL receptor and chylomicron remnant receptor, exists in 3 forms: E2, E3, and E4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Increased production of VLDL

A

by liver, caused by excessive intake of carbs, saturated fatty acids, and trans fatty acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Lipoprotein (a)

A

LDL-like particles with 1 molecule of apo (a) linked to apo B-100, heterogenous in size and density with plasma concentration widely distributed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

elevated concentration of lipoprotein (a)

A

Increased risk for premature coronary heart disease and stroke due to inhibitory effect on plasminogen, a protein that enhance clot lysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Spherical HDL

A

more lipid, cholesterol esters and triglycerides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Discoidal HDL

A

contains apo A-I to form a ring around central lipid bilayer of phospholipid and cholesterol, represents newly secreted HDL and the active form in removing cholesterol from peripheral cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Lipoprotein metabolism

A

Absorption pathway, exogenous pathway, or endogenous and other pathways

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Lipid absorption

A

Digestion of dietary lipids and absorption through passive transport via specific transporters, pass into portal circulation for short chain fatty acids but packaged into chylomicrons, re-esterified from monoglycerides and diglycerides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Triglyceride digestion

A

Monoglycerides and diglycerides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Cholesterol ester digestion

A

free cholesterol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Phospholipid digestion

A

lysophopholipids and bile acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Exogenous pathway

A
  1. Chylomicrons interact with proteoglycans on surface of capillaries
  2. Binding of LPL to hydrolyze triglycerides on chylomicrons to produce fatty acids and glycerol
  3. Products (free fatty acids and glycerol) taken up as energy source
  4. Re-esterified into triglycerides for storage in intracellular lipid drops in fat
  5. Adipose cells release fatty acids from triglycerides by hormone sensitive lipase, regulated by epinephrine/cortisol/insulin
  6. Chylomicrons converted to chylomicron remnant after transferring lipid and apolipoproteins onto HDL
  7. Chylomicrons remnant taken via specific remnant receptors on liver cells
  8. Release fatty acids, cholesterol and AA by lysosomal enzymes
  9. Cholesterol and bile acids excreted into the bile with half cholesterol and almost all of the bile acids reabsorbed by the intestine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Lipid and lipoprotein levels in women

A

increased HDL, decreased total cholesterol and triglyceride

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Lipid and lipoprotein levels in children

A

Decreased total cholesterol, LDL and triglycerides, no change in gender, HDL comparable to adults

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Lipid and lipoprotein levels by age

A

Increase total cholesterol, LDL and triglyceride with age

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Lipid and lipoprotein levels increasing risk of heart diseases

A

Increased serum cholesterol level, influenced by diet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Diseases related to lipid metabolism

A

Arteriosclerosis, hyperlipoproteinemia, hypertriglyceridemia, combined hyperlipoproteinemia, lipoprotein (a) elevation, hypolipoproteinemia, hypoalphalipoproteinemia

44
Q

Dyslipidemias

A

Caused by abnormal synthesis, transport or catabolism of lipoproteins

45
Q

Hypoalphalipoproteinemia

A

Decreased HDL due to genetic defects, associated with increased risk of CHD

46
Q

Hypertriglyceridemia

A

caused by genetic or acquired diseases, such as hormonal diseases and DM, mainly derived from an imbalance between synthesis and clearance of VLDL, potentially treatable risk factor for VDH

47
Q

Hypercholesterolemia

A

Autosomal dominant with total cholesterol as high as 1000 mg/dL, leads to heart attacks in teenagers, heterozygotes with total cholesterol 300-600, heart attack 20-50s, xanthomas, elevated LDL cholesterol, increased synthesis of cholesterol cells for cell membrane and hormone production due to decreased uptake of cholesterol by cells

48
Q

Combined hyperlipoproteinemia

A

increased serum total cholesterol and triglycerides with increased risk for CHD, 4 forms

49
Q

Lipoprotein (a) elevation

A

Increase the risk of CHD and CVD, especially in conjunction with elevated LDL, homologous to coag factor, plasminogen so may compete with plasminogen for fibrin binding sites to increase plaque formation

50
Q

Cholesterol measurement

A

Hexane extraction after hydrolysis with alcoholic KOH followed by reaction with Liebermann-Burchard color reagent, enzymatic method commonly used nowadays with adequate accuracy but no pretreatment

51
Q

Triglyceride measurement

A

Enzymatic reactions widely on automatic chemistry analyzers, endogenous free glycerol contributing 10-20 mg/dL, overestimation of triglyceride can be corrected by calibration blanking, accuracy less important compared to cholesterol due to large physiologic variation

52
Q

High-density lipoprotein measurement

A

Measured as risk factor and in treatment decisions, homogenous methods automate HDL measurement, reference method developed at CDC

53
Q

Low-density lipoprotein measurement

A

Primary basis for treatment decisions in the NCEP guidelines, beta-quantification: combine ultracentrifugation, apply Friedwals calculation

54
Q

Renal functions

A

Urine formation, regulation of fluid and electrolyte balance, regulation of acid-base balance, excretion of waste products of protein metabolism, hormonal function

55
Q

Glomerular function

A

Filter blood, allowing water, glucose, amino acids, urea, creatinine and other molecules to pass freely but retain albumin, other plasma proteins, cells and protein bound substances, filter function caused by steep pressure difference across capillary walls, measurement of the volume of blood filtered/min important for evaluating renal function

56
Q

Tubular function

A

Receive and contain filtrate with both waste products and essential molecules, reabsorb compounds like NA+, Cl, glucose, amino acids, vitamins, proteins, ions, reabsorption is active and saturable, secrete products of renal tubular cell metabolism, like H+ and drugs

57
Q

Function of Henle’s loop

A

Provide countercurrent multiplier system, maintain hyperosmolality in interstitial space by pumping Cl and Na into it by ascending loop, which facilitates the reabsorption of water

58
Q

Function of distal tubule

A

Maintain electrolyte balance and acid-base homeostasis, under control of aldosterone, releasing in response to decreased blood flow in the afferent renal arteriole and regulated mainly by renin-angiotensin, reabsorption of Na and secretion of K and H that is associated with HCO3 and ammonia secretion

59
Q

Function of collecting duct

A

Reabsorption of Na controlled by aldosterone, reabsorption of water, controlled by ADH, released when increased blood osmolality or decreased intravascular volume, responsible for producing concentrated urine

60
Q

Elimination of urea

A

Majority of non-protein nitrogenous compound that is filtered by glomerulus and partially reabsorbed, depending on GFR, the plasma renal flow and urine flow rate

61
Q

Elimination of creatinine

A

formed from creatine + ATP, filtered by the glomerulus but not reabsorbed, small amount secreted into urine, levels in blood are a function of muscle mass and GFR

62
Q

Elimination of uric acid

A

Major metabolic product of purine, filtered by glomerulus, can be reabsorbed and secreted, secretion into urine may lead to urolithiasis and gout when urine pH is low

63
Q

Endocrine function of kidney

A

Produce renin, a member in the renin-angiotensin-aldosterone feedback system, in response to decreased extracellular fluid volume, generate erythropoietin whose level is regulated by blood oxygen levels, produce 1,25-dihydroxy Vitamin D3

64
Q

Acute glomerulonephritis

A

Related to recent infection by group A beta hemolytic strep where the circulating immune complexes leads to an inflammatory response in the glomerular basement membrane, causing its injury, acute kidney infections and drug-related exposures, rapid onset of hematuria and proteinuria with decreased GFR, anemia, elevated serum creatinine, hyaline and granular casts and blood cell casts

65
Q

Chronic glomerulonephritis

A

Result from renal disease or idiopathic cause, not recognized for long period because of slight decrease of renal function, proteinuria and hematuria, leads to glomerular scarring, gradual develop of uremia and eventual loss of functional nephrons

66
Q

Nephrotic syndrome

A

Caused by increased permeability of the glomerular basement membrane, evidenced by massive proteinuria, resulting in hypoalbuminemia, decreased plasma oncotic pressure, generalized edema, development of hyperlipidemia and lipiduria

67
Q

Tubular diseases

A

Can be part of the progression of all renal diseases with GFR falls or is the only manifestation, show decreased excretion/reabsorption and compromised concentrating capacity, primary tubular disorder affects acid-base balance, causing renal tubular acidosis

68
Q

Acute renal failure

A

Sudden decline in renal function, shown as GFR lass than 10 mL/min, oliguria and anuria, resulting in decreased secretions of electrolytes and water, leads to increased extracellular fluid, causing peripheral edema, hypertension, hyponatremia, hyperkalemia and CHF

69
Q

Chronic renal failure

A

Gradual decline in renal function over time, stage 1 undetectable, stage 2 slight insufficiency, stage 3 abnormal high serum BUN and creatinine, development of anemia and systemic acidosis, stage 4 class symptoms of uremic syndrome

70
Q

Renal function assessed by measuring creatinine

A

Standard method to measure GFR, creatinine produced at constant rate, colorimetric methods, direct relationship with muscle mass makes serum creatinine high in males and low in females

71
Q

GFR equation

A

Urine creatinine concentration X urine volume excreted in 24 hours / serum creatinine concentration x 1440 minutes, modified by normalization factor 1.73/A

72
Q

Estimated GFR

A

Recommended by National Kidney Foundation, calculated based on serum creatinine, age, body size, gender and race when creatinine is reported, designed to detect chronic kidney disease earlier since it doesn’t require a timed specimen

73
Q

eGFR equation

A

GFR = (140-age) X weight / (72 X serum creatinine concentration), modified by 0.85 if female

74
Q

Renal function by measuring urea

A

Used in past, 40% or urea is reabsorbed after being filtered at the glomerulus

75
Q

renal function by systatin C

A

A small protein molecule produced by nucleated cells, filtered by glomerulus followed by reabsorption and catabolism by the proximal tubule, serum concentration not affected by gender, age, race and muscle mass, abnormal values appear earlier before a decrease in GFR or increase in serum creatinine

76
Q

Urea

A

makes about half the NPN molecules in blood, synthesized in liver from CO2 and ammonia, main excretory product of protein metabolism, readily filtered from plasma by glomerulus and half is reabsorbed, plasma urea affected by renal function and perfusion, protein content and catabolism

77
Q

Why is BUN used for measurement of blood urea

A

Assays for urea were based on nitrogen measurement

78
Q

Decreased serum/plasma urea seen in

A

Decreased protein intake, severe liver diseases

79
Q

Differentiation of prerenal, renal and postrenal diseases

A

High BUN:Creatinine seen in prerenal diseases that only increase urea, high ratio with elevated creatinine seen in postrenal, low ratio seen in low protein intake, acute tubular necrosis and severe liver disease

80
Q

Normal BUN/Creatinine ration

A

10:1 to 20:1

81
Q

Urea measurement

A

Reported in terms of nitrogen concentration

82
Q

Enzymatic urea measurement

A

Hydrolysis of urea by urease and quantitation of NH4+

83
Q

Electrode urea measurement

A

Measure the rate of increase in conductivity due to production of NH4+

84
Q

Chemical urea measurement

A

Measure the yellow color from direct condensation with diacetyl monoxime in the presence of strong acid and oxidizing agent, or measure colored compounds formed between urea and O-phthalaldehyde and naphthyethylenediamine

85
Q

Isotope-dilution mass spectrometry urea measurement

A

Definitive method for urea measurement

86
Q

Specimen requirements and interfering substances

A

Avoid urease inhibitors such as Na+ F or Na+ citrate when collecting, fasting specimen is not required due to single protein diet has very small effect, refrigerate samples if not analyzed right away because urea is susceptible to bacteria decomposition, preserve urine samples with few crystals of thymol when analyzing urine urea, may need to modify method used to measure serum urea for urine measurement if urine specimens contain high concentration of urea and ammonia compared to serum sample

87
Q

Creatinine

A

Derived from creatine phosphate, synthesized in liver before transported to other tissues, released into circulation as relatively constant rate, proportional to muscle mass, eliminated by glomerular filtration and a small amount secreted by proximal tubule, plasma levels reflect relative muscle mass and renal function, elevated plasma levels associated with decreased renal function

88
Q

Elevated serum/plasma creatinine

A

Mainly caused by abnormal renal function, the clearance of creatinine : the volume of plasma from which creatinine is cleared /min reflects GFR that determines renal function, diet does not affect, most commonly used monitor of renal function

89
Q

Jaffe reaction

A

previously considered reference method creatinine in protein-free filtrate adsorbed onto Fuller’s earth, then released with alkaline pictrate to yield colored Janovski complex

90
Q

Creatininase-CK

A

generate NAD+ through a serious coupled reaction, not widely used due to large sample requirement

91
Q

Myoglobin

A

Function to bind and transport oxygen from the plasma membrane to the mitochondria in muscle cells, released into blood stream in skeletal and cardiac muscle injury, mainly bound to plasma proteins so filtration through glomerulus is not as much as predicted from size, can induce acute renal failure if its release from muscle overloads the renal proximal tubules to cause myoglobinuria

92
Q

Urinalysis physical features

A

Morning specimens preferred, especially for protein measurement, should be obtained by clean midstream catch into a clean and dry container with tight-fitting cover, be analyzed within 1 hour of collection at room temp or refrigerated for < 8 hours

93
Q

Urine color

A

The darker the color, the more concentrated the specimen, yellow-amber due to urobilin, yellow-brown due to bile pigment, red-brown due to porphyrins or hemoglobin or RBCs, brown-black due to alkaptonuria and malignant melanoma

94
Q

Urine odor

A

Pungent odor due to volatile aromatic acids, ammonia odor due to allowed to stand, noxious, fecal smell due to UTIs, fruity due to ketones, maple sugar due to maple sugar urine disease

95
Q

urine turbidity

A

in alkaline due to suspended precipitates of amorphous phosphates and carbonates, in acidic due to amorphous urates, cloudiness due to gross bacteriuria, smoke due to hematuria, threadlike due to mucus

96
Q

Urine volume

A

Normal: 750-2000 mL/24 hours
Polyuria due to diabetes, chronic renal disease and myxedema, oliguria or anuria due to nephritis, end stage renal disease, urinary tract obstruction and acute renal failure

97
Q

UA requirements

A

10-12 mL aliquot from well-mixed sample

98
Q

Specific gravity

A

The weight of 1 mL or urine (g) / the weight of 1 mL of water, usually measured by refractometer, indication of hydration and concentrating abilities

99
Q

Low specific gravity

A

Due to diabetes insipidus, pyelonephritis and glomerulonephritis

100
Q

High specific gravity

A

Due to diabetes mellitus, CHF, dehydration, adrenal insufficiency, liver disease and nephrosis

101
Q

Urine pH

A

measurement on fresh urine because of alkalization on standing, normal: 4.5-8.0

102
Q

Urine acidity

A

Due to phosphates and NH4+, excretion of nonvolatile metabolic acids, metabolic acidosis

103
Q

Alkaline urine

A

Due to ingestion of alkaline food or medication, UTIs and bacterial contamination, Fanconi’s syndrome

104
Q

Nitrite analysis

A

Assesses amount of urinary reduction of nitrate by the enzyme of gram-negative bacteria, positive results in some gram-negative bacterial infection although negative result doesn’t rule out due to not producing nitrate-reducing enzymes and urine may not have been retained in bladder long enough

105
Q

Leukocyte esterase

A

Positive dipstick for esterases indicates possible WBC in specimen

106
Q

Bilirubin/urobilinogen

A

Glucose, ketones and protein

107
Q

Hemoglobin/blood analysis

A

positive dipstick results indicate renal trauma/injury, infection or obstruction from stones or cancer/tumors