M3U3: BLOOD, PORPHOBILINOGEN, BILIRUBIN AND UROBILINOGEN

Question 1

a red coloured urine is often associated with

Answer 1

the presence of blood as either hematuria or hemoglobinuria

Question 2

This refers to the increased presence of intact red blood cells

Answer 2

hematuria

Question 3

this refers to the increased urinary presence of hemoglobin

Answer 3

hemoglobinuria

Question 4

___ is associated with free intravascular hemoglobin that traversed the glomerulus and became part of the plasma ultrafiltrate in the tubules

Answer 4

true hemoglobinuria

Question 5

the primary content of hemoglobin that allows it to carry oxygen

Answer 5

heme

Question 6

This is a porphyrin precursor that is an intermediate compound in the formation of heme

Answer 6

porphobilinogen

Question 7

how is porphobilinogen formed ?

Answer 7

from the condensation of two σ-aminolevulinic acid (ALA) molecules in the presence of ALA dehydratase

Question 8

what are the 3 porphyrinogens and their respective porphyrins ?

Answer 8

uroporphyrinogen = uroporphyrin
coproporphyrinogen = coproporphyrin
protoporphyrinogen = protoporphyrin

Question 9

Normally, the body regulate heme synthesis in such a way it forms how much of ALA and PBG ?

Answer 9

ALA = <1.4 mg/dL
PBG = <0.4 mg/dL

Question 10

This is characterized by the accumulation of porphyrin precursors in the body

Answer 10

porphyria

Question 11

accumulation of porphyrin precursors in the urine

Answer 11

porphyrinuria

Question 12

___ is an orange-yellow pigment that imparts a characteristic colour in urine and plasma when produced excessively or when it accumulates in the body

Answer 12

bilirubin

Question 13

Bilirubin is formed from the heme-containing proteins such as ___

Answer 13

cytochrome, myoglobin, and hemoglobin

Question 14

Primarily, bilirubin is formed from ___

Answer 14

hemoglobin released in the physiologic destruction of old red blood cells

Question 15

When heme is released in the ___, it undergoes catabolism to form ___

Answer 15

peripheral tissues

bilirubin

Question 16

The initial bilirubin (unconjugated bilirubin) is formed in the ___ as a result of ___

Answer 16

bloodstream as a result of the rapid reduction of biliverdin

Question 17

Why is the initial bilirubin bound to albumin in the bloodstream ?

Answer 17

to prevent its deposition in tissues where it can be toxic

Question 18

The bilirubin-albumin complex is transported to the ___ where it is rapidly ___ to make it water soluble

Answer 18

liver

conjugated with glucuronic acid

Question 19

The conjugated bilirubin formed is eventually transported to the ____ and ultimately leading it to the ___

Answer 19

bile duct

small intestines

Question 20

____ is a colorless substance

Answer 20

urobilinogen

Question 21

The plasma urobilinogen readily passes through the glomerular filtration barrier and is excreted in urine by how much ?

Answer 21

1 mg/dL or less

Question 22

urobilinogen and stercobilinogen present in the intestine undergoes ____ forming urobilin and stercobilin

Answer 22

spontaneous oxidation

Question 23

____ imparts a characteristic orange-brown colour on feces

Answer 23

urobilin and stercobilin

Question 24

a tea-coloured urine indicates increased ____

Answer 24

urinary urobilinogen

Question 25

hematuria is commonly observed in cases of ____ (6)

Answer 25

``` kidney or urinary tract diseases trauma drug therapy strenuous exercise hypertension smoking ```

Question 26

Examples of renal or urinary tract diseases that may cause hematuria includes ____ (5)

Answer 26

``` glomerulonephritis pyelonephritis cystitis renal stones tumors ```

Question 27

Administration of medications such as ___ may induce hematuria as well

Answer 27

cyclophosphamide | anticoagulants

Question 28

This is when intact red cells that pass through the urinary tract undergoes lysis in urine, liberating hemoglobin

Answer 28

hemoglobinuria

Question 29

Examples of conditions that causes hemolytic episodes include but not exclusive to ___

Answer 29

transfusion reactions hemolytic anemia paroxysmal nocturnal hemoglobinuria

Question 30

An indicator of true hemoglobinuria as a result of intravascular hemolysis is the ____

Answer 30

presence of hemosiderin granules

Question 31

Why is it important to note that the presence of hemosiderin granules should not be the sole basis for confirming a hemolytic episode ?

Answer 31

urinary hemosiderin excretion

Question 32

___ is an insoluble storage form of iron

Answer 32

hemosiderin

Question 33

Normal value of urobilinogen

Answer 33

<0.1 mg/dL

Question 34

Normal value of conjugated bilirubin

Answer 34

<0.2 mg/dL

Question 35

Normal value of unconjugated bilirubin

Answer 35

0.8-1.0 mg/dL

Question 36

Normal value of haptoglobin

Answer 36

83-267 mg/dL

Question 37

Normal values of free hemoglobin

Answer 37

1-5 mg/dL

Question 38

Other causes of hemoglobinuria

Answer 38

extensive burns malaria syphilis chemical toxicity (copper nitrites nitrates) exertional hemolysis associated to marching long distance running karate

Question 39

How is myoglobin compound similar to hemoglobin as ___

Answer 39

it contains heme to facilitate transport of oxygen in muscles

Question 40

Normally the excretions of myoglobin in urine ___

Answer 40

<0.04 mg/dL

Question 41

Myoglobin is released in the circulation as a result of ___ (3)

Answer 41

muscle damage due to injury (trauma) pathology (ischemia, infections, myopathy, toxins, convulsions)

Question 42

____ also affects the delivery of oxygen resulting to muscle ischemia (3)

Answer 42

``` carbon monoxide poisoning alcohol intake illicit drug (heroin) ```

Question 43

____ is caused by an imbalance between energy consumption and production resulting to incontrollable contractions leading to ___

Answer 43

seizures or convulsions muscle damage

Question 44

Medications such as __ may cause myopathy and manifests myoglobinuria

Answer 44

steroid and retroviral agents

Question 45

____ is more toxic to the renal tubules that hemoglobin

Answer 45

myoglobin

Question 46

why is myoglobin more toxic to the renal tubules than hemoglobin ?

Answer 46

may be associated with their glomerular clearance and other factors such as hydration, hypertension, and aciduria

Question 47

Myoglobin at a urine excretion of ___ is associated with a patient's risk of developing acute renal failure

Answer 47

1.5 mg/dL

Question 48

serum color of hemoglobinuria

Answer 48

pink to red

Question 49

serum colour of myoglobinura

Answer 49

pale yellow

Question 50

urine colour of myoglobinuria

Answer 50

pin red brown at 25 mg/dL

Question 51

Serum chemistry test result for hemoglobinuria

Answer 51

haptoglobin: decreased to absent myoglobin: normal free hemoglobin: increased creatinine kinase: increased <10x upper limit

Question 52

Serum chemistry test result for myoglobinuria

Answer 52

haptoglobin: normal myoglobin: increased free hemoglobin: normal creatinine kinase: increased >10x upper limit

Question 53

normally, ___ of bilirubin is present in urine

Answer 53

0.02 mg/dL

Question 54

urobilinogen is normally present in urine in concentrations of ___

Answer 54

≤1 mg/dL 1 Ehrlich unit range: 0.5-2.5 mg/day

Question 55

____ are early indicators of liver diseases, even before other symptoms such as jaundice manifests

Answer 55

bilirubinemia and bilirubinuria