connective tissue 3

leucocytes

involved in immune response, wandering cells in ct and circulation, infected tissues, all from CT origin (bone marrow)

granular leukocytes

no prominent granules, lymphocytes( t, B, and NK cells) and monocytes, macrophages

granular leukocytes

polymorphonuclear leukocytes, PMNs or PMLs, eosinophils, neutrophils, basophils, and mast cells

macrophage (histocytes)

2nd most abundant cell type in areolar CT, esp in vascular areas, goes from BM to blood to CT, which it changes into a macrophage from a monocyte, phagocytic, irregular outline, nucleus oval(may be slightly indented, dark staining

phagocytic

activated by inflammation (IC, complement, cytokines, TolR), ingest
particles, microbes to present to T-lymphocytes, initiating immune response

Langerhan’s Giant Cells

giant, multinucleated fusion of macrophages, isolates the pathogen from the rest of the body, common in TB

T lymphocytes

Cell Mediated Immunity, CD4+ aid in activating B-cells leading to antibody response, CD8+ (cytotoxic T cells) kill virally infected cells

B lymphocytes

Humoral Immunity Give rise to plasma cells which produce antibody

natural killer cells

Kill virally infected cells, non-antigen specific*Indistinguishable histologically: Small cell little cytoplasm. Nucleus stains deep purple in H&E stain (“little purple dots”) (*will go into more detail in Blood section)

Plasma Cells

common in LCT esp lamina propria of respitory tract, serous membrane, gastrointes tract, lymphoid tissue, B- lympho diff, nucleus oval-round, chromatin spokes/clock due to heterochromatin, area near nuc colorless.

granulocytes

neutrophils , eosinophils, mast, basophils

neutrophils

phagocytes, typically first responder to infection (MFs are 2nd), 2-4 lobes in nucleus, used granules to kill engulfed bacteria

eosinophils

may also be in infected tissue, release numerous granules in response to parasitic infection or allergic rxn.

mast cells

involved in the allergic rsp, , similar to basophils, but found only in tissues

basophils

similar to mast cells, but much smaller and are only found in blood(rate)

Mast Cells

3rd abundant CT cell type in LCT, capillaries of the skin, pale nucleus, packed w.granyles of histamine, heparin, proteases, cytokines, and chemokines, membrane delicate ruptures during fixation (degranulation), role in inti. of immune and allergic rsp. Fc3R1 in the surface binds IgE Ab= complement comp. causes degrandulation