Pigments- Casimir

Question 1

Exogenous pigments

Answer 1

• from external surface
• coal
• carotenoid
• tetracycline

Question 2

Endogenous pigments

Answer 2

• from inside body
• melanin

Question 3

Hematogenous pigments

Answer 3

• hemoglobin
• hematin
• hemosiderin
• hematoidin
• bilirubin
• porphyria

Question 4

Coal dust

Answer 4

• most common exogenous pigment

Question 5

Anthracosis

Answer 5

• coal pigment blackens tissues in lungs & involved LN
• common in older animals
• 2ndary to polluted air
• macrophages phagocytose coal in alveoli -> transported via lymph channels to regional LN in tracheobronchial region

Question 6

What does anthracosis look like histologically

Answer 6

• C in alveolar spaces
• macrophages blackened & transported to BALT
• tracheobronchial LN
• fine, black, granular crystallized

Question 7

What does anthracosis look like grossly?

Answer 7

• fine gray-black stippling
• gray discoloration of tracheobronchial LN

Question 8

Differential for anthracosis

Answer 8

Melanoma

Question 9

How to diagnose tumor from pigment

Answer 9

Cytology

Question 10

Carotenoid pigments

Answer 10

• yellow coloration to plasma, adipose tissue, any lipid laden cells
• alpha and beta carotene abundant in leafy greens
• herbivores have deep yellow color b/c of lush, green pasture
• dietary indicator not lesion

Question 11

Tetracycline pigment

Answer 11

• negative effect on fetus during pregnancy
• binds to calcium chlorate in teeth and bones
• permanent discoloration if admin. to animals during time of teeth mineralization
• yellow staining until exposed to light. Then turns brown via oxidation

Question 12

Melanin

Answer 12

• responsible for coloration in hair, skin, and iris
• from neural crest, migrates to site of pigment prod. during embryonic development

Question 13

Histological description of melanin

Answer 13

• brown
• in stratum basale of epidermis & follicular epithelium
• hypo/hyper- pigmentation in diseased state

Question 14

Congenital Melanosis

Answer 14

• leptomeninges have cattered black areas of melanin; normal in black ruminants
• subpleural melanin deposits extend into pulmonary parenchyma in red/black pigs; no detrimental consequences

Question 15

Intravascular hemolysis

Answer 15

• Hgb released gives plasma/serum pink tinge
• renal parenchyma= dark red-gunmetal blue
• myoglobinuria

Question 16

Pathology of IV hemolysis in kidneys

Answer 16

• IV Hgb passes thru glomerular capillaries -> Hgb casts formed in renal tubules-> hemoglobinuria

Question 17

What causes IV hemolysis in equines?

Answer 17

Red maple toxicosis

Question 18

In what type of animal is myoglobinuria seen?

Answer 18

• racehorses

Question 19

Hematin

Answer 19

• brown-black colored
• contains Fe3+
• caused by oxidation of Hgb
• 2 types: acid and parasitic

Question 20

Parasitic hematin

Answer 20

• parasites consume RBCs, liberate heme during Hgb proteolysis
• parasites convert hematin-> beta hematin
• hematin colors migration tracts of juvenile liver flukes black

Question 21

Acid hematin

Answer 21

Caused by acidic formalin

Question 22

Bilirubin

Answer 22

• product of RBC break down
• Hgb broken down in macrophage -> heme converted to biliverdin -> bilirubin
• 2 types: unconjugated & conjugated

Question 23

Unconjugated bilirubin

Answer 23

In blood

Question 24

Conjugated bilirubin

Answer 24

In liver

Question 25

Prehepatic bilirubin

Answer 25

• increases turnover of RBCs & delivers more unconjugated bilirubin to liver than it can hold
• causes: anemia, blood loss, Fe2+ deficiency

Question 26

Hepatic bilirubin

Answer 26

• hepatocellular injury that decreases uptake, conjugation, or secretion of bilirubin
• causes: onion & garlic

Question 27

Posthepatic bilirubin

Answer 27

• flow of bile from liver -> intestine via biliary syst. is reduced by an obstruction
• causes: gallbladder stones

Question 28

Jaundice is easiest to see in what kind of tissues?

Answer 28

Pale or colorless