Pigments- Casimir Flashcards
Exogenous pigments
- from external surface
- coal
- carotenoid
- tetracycline
Endogenous pigments
- from inside body
- melanin
Hematogenous pigments
- hemoglobin
- hematin
- hemosiderin
- hematoidin
- bilirubin
- porphyria
Coal dust
- most common exogenous pigment
Anthracosis
- 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
What does anthracosis look like histologically
- C in alveolar spaces
- macrophages blackened & transported to BALT
- tracheobronchial LN
- fine, black, granular crystallized
What does anthracosis look like grossly?
- fine gray-black stippling
- gray discoloration of tracheobronchial LN
Differential for anthracosis
Melanoma
How to diagnose tumor from pigment
Cytology
Carotenoid pigments
- 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
Tetracycline pigment
- 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
Melanin
- responsible for coloration in hair, skin, and iris
- from neural crest, migrates to site of pigment prod. during embryonic development
Histological description of melanin
- brown
- in stratum basale of epidermis & follicular epithelium
- hypo/hyper- pigmentation in diseased state
Congenital Melanosis
- 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
Intravascular hemolysis
- Hgb released gives plasma/serum pink tinge
- renal parenchyma= dark red-gunmetal blue
- myoglobinuria
Pathology of IV hemolysis in kidneys
- IV Hgb passes thru glomerular capillaries -> Hgb casts formed in renal tubules-> hemoglobinuria
What causes IV hemolysis in equines?
Red maple toxicosis
In what type of animal is myoglobinuria seen?
- racehorses
Hematin
- brown-black colored
- contains Fe3+
- caused by oxidation of Hgb
- 2 types: acid and parasitic
Parasitic hematin
- parasites consume RBCs, liberate heme during Hgb proteolysis
- parasites convert hematin-> beta hematin
- hematin colors migration tracts of juvenile liver flukes black
Acid hematin
Caused by acidic formalin
Bilirubin
- product of RBC break down
- Hgb broken down in macrophage -> heme converted to biliverdin -> bilirubin
- 2 types: unconjugated & conjugated
Unconjugated bilirubin
In blood
Conjugated bilirubin
In liver
Prehepatic bilirubin
- increases turnover of RBCs & delivers more unconjugated bilirubin to liver than it can hold
- causes: anemia, blood loss, Fe2+ deficiency
Hepatic bilirubin
- hepatocellular injury that decreases uptake, conjugation, or secretion of bilirubin
- causes: onion & garlic
Posthepatic bilirubin
- flow of bile from liver -> intestine via biliary syst. is reduced by an obstruction
- causes: gallbladder stones
Jaundice is easiest to see in what kind of tissues?
Pale or colorless
