Histo/Immune System/Cell Injury Flashcards
RBC lifespan
120 days
Hct
volume of packed cells (%)
Hgb
g Hgb / L
MCV
mean corpuscular volume
mean RBC volume
MCH
mean corpuscular Hgb
amount of Hgb in a given cell
MCHC
Mean corpuscular Hgb concentration
Hgb concentration of average RBC
RDW
coefficient of variation about mean RBC size (higher means more variation)
reitculocyte
immature RBC recently entered into circulation, blueish
Microcytic hypochromic anemia
low MCV, low MCH, low MCHC
Causes: iron deficiency, thalassemia
Macrocytic anemia
High MCV
Causes: Megaloblastic anemia (vit B12 deficiency), alcohol
Normocytic normochromic anemia
normal MCV, MCH, MCHC
Causes: anemia of chronic disease, acute blood loss, hemolytic anemia
anisocytosis
variation in red cell size
poikilocytosis
variation in red cell shape
schistocyte
fragmented red cell, torn or split or broken
The great RBC schism …
Target cell
red cell in which Hgb appears concentrated, seen in thalassemias
drepanocyte
sickle cell
spherocyte
spherical without central pallor, hyperchromic
hypochromic
pale
platelet
blue-purplish granules, small
Neutrophil
- myeloid, granulocyte
- most abundant
- multilobular
- first response phagocytosis
eosinophils
- myeloid granulocyte
- dense pink granules
- seen in parasitic infection, releases MBP
basophils
- myeloid granulocyte
- blue granules, usually can’t see nucleus, relatively rare
- release histamine and heparin
mast cell
- myeloid granulocyte
- in mucosal tissues, secretes histamine and heparin, eosinophilic chemotactant factor
Monocyte/Macrophage
- circulating/tissues
- has cytoplasmic vacuoles
- phagocytosis and antigen presentation via MHCII
NK cells
- lymphoid derived
- will kill things no presenting MHCI (self)
Dendritic cells
- never circulating
- presents antigen via MHCII, calls second line into action
- best antigen presenter
B cells
- antibodies bind antigens
- antigen fragment presented on MHCII to T helper cells
- TH –> memory B cells, plasma B cells
T-helper
- forms memory T helper
- stimulates macrophages, B cells (memory and effector), neutrophils
- Respond to antigen presentation on MHCII: presented by macrophages, dendritic cells, B cells (specific)
T-cytotoxic
- forms more Tc
- releases perforin when cell presents foreign substance on MHCI
Which main cell types implicated in types of infections?
bacterial: neutrophils
viral: lymphocytes
parasitic: eosinophils
mycobacterial (TB): monocytes
general inflammatory: basophils
myeloid left shift
bone marrow releasing myeloid cells before they are fully developed, commonly occurs in infection, malignancy, drug reaction
- appears more blue, high N:C ratio
Cells with MHCII
- dendritic (best antigen presenters)
- macrophages
- B cells
Cells with MHCI
all self-cells, dendritic cells
Which cells can phagocytose?
- neutrophils
- macrophages
- dendritic cells
- mast cells
Which cells kill self-cells that aren’t presenting MHCI?
NK cells
Which cells kill cells presenting foreign material on MHCI?
T cytotoxic
ATP depletion leads to…
necrosis. Na+ accumulates in cell and it bursts
3 types of reversible cellular injury
- cellular swelling
- chromatin clumping
- fatty change
coagulative necrosis
characteristic of infarcts in all solid organs except brain
- basic tissue architecture preserved
caseous necrosis
- encountered most often in foci of TB infection
- caseating granulomas
liquefactive necrosis
- focal bacterial infections
- liquid = pus
fat necrosis
- chalky white areas of fat saponification
fibrinoid
- seen in immune reactions involving blood vessels,
Clinical signs of acute inflammation
- rubor and calor: redness and warmth due to vasodilation
- tumor: swelling (first transudative due to increased hydrostatic pressure, then exudative due to increased vascular permeability)
- dolor: pain resulting from bradykinins, etc
- fever
vascular change in acute inflammatory response
- vasodilation
- vascular permeability
- vascular congestion
- accumulation of neutrophils and leukocytes
Differentiation acute and chronic inflammation histologically
acute will have lots of neutrophils (appear as multilobular)
chronic will have lots of lymphocytes (dark round nucleus)