Pigments And Tissue Deposits Flashcards
What are the hematogenous pigments?
Hemoglobin
Hemosiderin
Bilirubin
Porphyrin
What pigments are responsible for the colours of a bruise
Hemoglobin
Bilirubin
Hemosiderin
Biliverdin
What pigment is yellow in colour
Bilirubin
Hemoglobin is broken down into what molecules
Fe -> hemosiderin
Heme -> bilirubin
Globin -> amino acids
Unconjugated bilirubin is carried by __________ to the liver
Albumin
What enzyme conjugates bilirubin in the liver to make it soluble for secretion?
Diglucuronide
Too much bilirubin in the blood is AKA as _________
Hyperbilirubinemia
When bilirubinis»_space; 2mg/dl you get __________
Jaundice/icterus
What are the three ways that you can have hyperbilirubemia ?
Prehepatic (hemolytic
Hepatic (hepatocellular)
Posthepatic (obstructive)
What is prehepatic hyperbilirubinemia?
Bilirubin production exceeds hepatocellular uptake
Hemolysis (intravasular or extravascular)
What is hepatic hyperbilirubinemia?
Hepatocellular dysfunction
- decreased bilirubin uptake
- decreased conjugation
- decreased secretion on bile
Cause: hepatic insufficiency, hepatitis, hetaptocellular degeneration
What is extravascular hemolysis ?
RBC in tissue are lysed.
Hemoglobin is not free in blood (in spleen> splenomegaly)
What is intravascular hemolysis?
RBC are lysed in vessels-> Hemoglobin remains in the blood-> filtered by kidney
What is hemoglobinuria?
Hemoglobin in urine
How does hemoglobin appear in urine and in serum?
Urine - red-brown coloration (blood in urine can look similar but blood will settle, hemoglobin does not)
Serum - pink
What are the etiologic of hemolysis?
Oxidative damage Immune-mediated (common in dog) Infectious Direct membrane damage Erythrocytes metabolic deficiency
An animal that is anemic, has a swollen spleen, and is jaundiced has what type of hemoglobinemia?
Prehepatic
-> anemia -> hemolysis
What is hemosiderin ?
Iron stored intracellularly as ferritin
Grossly -brown colour
Microscopically - dark yellow to brown (stain with Prussian blue-> black)
What stain can you use to visualize hemosiderin?
Prussian blue/perls
Hemosiderin accumulation can be due to what local changes?
Chronic congestion
Hemorrhage
Hemosiderin accumulation can be due to what widespread changes
Hemolysis
Inherited disorders of Fe storage
What is erythropoietic porphyria?
Developmental anomaly of calves, cats, and pigs
Deficiency of prophyrinogen III -> defect in heme synthesis -> porphyrins
What is the gross appearance of erythropoietic porphyria?
Pink-red discoloration of bones and teeth
Fluorescent with UV light
What is the gross and histologically appearance of melanin?
Gross: Black/brown tissue colour
Histo: fine brow/black cytoplasmic granules
What enzyme is required for melanin synthesis
Tyronsinase
Dog with caudal area of alopecia, thickened skin, and darker in colour
Cutaneous hyperpigmentation
-> Flea allergy dermatitis (chronic inflammation)
What is derived from the breakdown of lipids and is an undegradable remnant of breakdown of organelles?
Lipofuscin
What are the exogenous pigments??
Carotenoids (vitamin A accumulation)-> red-orange
Carbon deposits -> black granular
Hematin -> black (parasitic)
Anticoagulant rodenticides -> blue
Tetracylines ->yellow discoloration of teeth
What tissue deposit is white gritty granules/plaques, grossly.
Calcification
What are the two types of calcification?
Dystrophic
Metastatic
What is dystrophic calcification?
Local disposition of calcium in areas of injury
Necrotic fat-calcium interact with fatty acid, producing insoluble calcium soaps (saponification)
Granuloma and dead parasites
What is metastatic calcification?
Widespread deposition of calcium in otherwise normal tissues
Caused by : Hypercalcemia
What are the predilection sites for metastatic calcification?
Vascular intima/adventitia Gastric mucosa Renal tubular epithelium Pulmonary intersitium Basement membranes
_____________ hormone reduces calcium
Calcitonin
____________ and ______________ increase calcium levels
Parathyroid hormone and vitamin D
What are the causes of hypercalcemia ?
Excess PTH
Excess vitamin D
What is calcinosis cutis? What is it caused by?
Widespread mineralization of the dermal collagen and epidermal basement membranes
Hyperadernocorticism
Long term corticosteroid treatment
What is amyloid?
Fibrils of stacked B-pleated sheets
Deposits and accumulation of amyloid in extracellular spaces causes _____________ of adjacent tissues
Compression and atrophy
Organs that are enlarged with waxy appearance and stains blue violet with treated with iodine + sulfuric acid
Amyloidosis
Histologically, what do you stain with to visulise amyloid ?
Congo red ->bring pink with green birefringence (polarized light)
Histologically, how does amyloid appear?
Homogenous eosinophilic extracellular material (hyaline)
What are the types of amyloid?
Amyloid light chain (immunoglobulin)
Amyloid A
Endocrine amyloid
AB amyloid
Will look the same no mature what it is made of
What is the pathogenesis of reactive systemic amyloidosis?
Chronic inflammation -> liver produces SAA in response to IL4 and IL6 -> spontaneous conversion of SAA to AA-> amyloid fibrils
What is the most common form of amyloidosis in animals and can be hereditary, affects kidney, spleen, liver, and lymph nodes.
Reactive systemic amyloidosis
Accumulation of uric acid in tissues causes?
Gout
Who produces uric acid as an excretion produce
Birds and reptile
Have no urinate (in mammals this enzyme helps in the process of uric acid to urea)
What is the end excretion product in mammals?
Urea
In the liver, myocardium, pleura, and spleen you see chalky white foci on the surface. What deposit is this?
Uric acid
How does uric acid appear histologically?
Clear spaces (crystals dissolve in processing)
Tophi- granulomatous inflammation surrounding the deposit
