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Flashcards in Pathology - General Deck (25):
1

Define Hypoxia

low O2 delivery to tissues

2

What are the three causes of hypoxia? Examples?

Ischemia, Hypoxemia, Decreased O2 carrying capacity
Ischemia: decreased blood flow; low arterial flow, venous blockage, systemic shock
Hypoxemia: low partial pressure of O2; high altitude, hypoventilation, diffusion defect, V/Q mismatch
Decreased O2 capacity: anemia, methemoglobinemia, CO poisoning

3

Coagulative necrosis

tissue remains firm and keeps its shape
ischemic infarction
wedge shaped area of necrosis
pale or red (red if re-perfusion injury)

4

Liquefactive Necrosis

enzymatic lysis of cells
Brain infarction, abscess, pancreatitis

5

Gangrenous Necrosis

resembles mumified tissue
characteristic of lower limb ischemia
if infection is superimposed on dead tissue -> wet gangrene

6

Caseous Necrosis

'cottage-cheese'
TB or fungal

7

Fat necrosis

deposits of calcium
trauma to fat (breast tissue) and pancreatitis mediated damage
process of calcium deposition is called saponification

8

Fibrinoid necrosis

necrotic damage to the blood vessel wall
bright pink stain
characteristic of malignant hypertension and vascultitis

9

Apoptosis enzymes

Caspases

10

Intrinsic apoptosis pathway

cellular damage lead to inactivation of bcl2, which normally stabilizes the mitochondrial membrane
destabilized mitochondrial membrane leaks cytochrome c which activates caspases

11

Extrinsic / receptor-ligand apoptosis pathway

FAS ligand binds FASr (CD95) on the target cell, which activates caspases
ex. negative selection of tcells in the thymus

12

Cytotoxic CD8 apoptosis pathway

perforins secreted by the CD8 cell create pores in the membrane; granzyme comes in through the pores and activate caspases

13

Name the antioxidant enzymes

superoxide dismutase: O2- to H2O2
Gluthathione peroxidase: 2GSH + radical = GSSH + H2O
Catalase: H2O2 to O2 and H2O

14

primary amyloid

AL amyloid from immunoglobulin light chain
asso: plasma cell dyscrasias, like MM

15

secondary amyloid

AA amyloid, from serum associated amyloid
chronic inflammation states

16

Function of CD14

recognizes LPS from gram negative bacteria (a PAMP)

17

Four attractants of neutrophils

LTB4, IL8, C5a, bacterial products

18

Steps of neutrophil arrival and function

Margination, Rolling, Adhesion, Transmigration and Chemotaxis, Phagocytosis, Destruction, Resolution

19

CD4 cell activation

extracellular antigen phagocytosed and presented on MHCII
2nd signal: B7 on the APC binds CD28 on the CD4 cell

20

Th1 products

secrete IFN-gamma, which activates macrophages; and IL2 which activates CD8 cells

21

Th2 products

secretes IL4/IL13, which helps Bcells class switch to IgE; and IL5,which helps Bcells class switch to IgA and eosinophil chemotaxis

22

CD8 cell activation

intracellular antigen is presented on MHCI
2nd signal is IL2 from CD4 Th1 cells

23

B cell activation

CD40 on B cells binds CD40L on helper t cells

24

Defining cell of a granuloma

epithelioid histiocyte
macrophage with lots of pink cytoplasm

25

Granuloma formation

macrophages secrete IL12 -> Th cells to Th1 type
Th1 cells secrete IFN-gamma, which converts macrophages to epithelioid histiocytes