35 terms

Inflammatory cells of Connective Tissue

Mansoor Lecture 1
Name the CT or structural cells/resident/fixed cells (4)
(1) fibroblasts (2) adipocytes (3) chondroblasts (4) osteoblasts q
Name the Wandering cells that migrate through the tissues as they perform surveillance functions (6)
(1) macrophages (2) mast cells (3) T lymphocytes (4) plasma cells (5) NK (6) eosinophils
Name the 10 inflammatory cells
(1) macrophages (2) mast cells (3) T lymphocytes (3) plasma cells (4) eosinophils (5) neutrophils (6) platelets (7) B lymphocytes (8) NK (9) endothelial cells (10) fibroblasts
What is the one inflammatory cells that re enters the blood stream
What is the process of inflammation?
(1) release of chemical mediators from plasma proteins/cells (2) mediators cause increased permeability of post capillary venule allowing leukocytes to enter into the CT (3) increases wandering cells in number and activates them into inflammatory cells of CT
Macrophage (histiocytes): (1) histological characteristics
(1) Nucleus--eccentric, ovoid, or kidney shaped with thin rim of condensed chromatin and one nucleolus. Border--ruffled, irregular due to active pinocytotic and phagocytic activiaties. Cytoplasm--frothy due to secondary lysosomes. Pathological conditions--epitheliod or may fuse to form multinucleated giant cells
Macrophages (2) lineage and (3) life span
(2) stem cells from bone marrow and enter the blood stream where they circulate for a few hours. When stimulated they leave the blood stream and enter the CT compartment and transform into macrophages where they survive from months to years
Macrophages; (4) function of inflammation
(1) clear and maintain CT (2) ingest effete red blood cells breaking hemoglbin into ferritin (3) Gather in large numbers and ingest/destroy bacteria by lysosomes (4) secrete enzymes/cytokines (5) process and present antigen to lymphocytes (6) provide cell mediated resistance against micro organism and tumors
Cells of th mononuclear phagocytotic system (MPS) (most derived from blood monocytes)
(1) macrophage (histiocyte)--CT
(2) perisinusoidal macropahge (kupffer cell)--liver
(3) Alveolar macrophage--Lungs
(4) macrophage--spleen, lymph nodes, bone marrow, and thymus
(5) pleural and peritoneal macrophage--serous cavities
(6) osteoclast--bone
(7) microglia--CNS
(8) Langerhans'cell--epidermis
(9)Fibr0blast-derived macrophage--lamina propia of intestine, endometrium of uterus
Mast Cell (1) histiologic characteristics
(1) Cells: ovoid or round about 10-13 um in diameter.
Nucleus: round or ovoid is is in the center.
Cytoplasm: contains basophilic cytoplasmic granules (not seen in HE but with toluidine blue dye). Mast cell stains red-purple (metachromatic) and a background stain of blue (orthochromatic)
Mast cell (2) lineage + (3) life span)
(2) arises in bone marrow, travels the blood stream and enters the CT (CT mast cells: skin, peritoneum) and mucosa (mucosal mast cells: lung and intestine). Mast cell divide in CT but their life span is unknown.
Mast cell (4) Function (6)
(1) release of chemical mediators or cytoplasmic granules of responsible for allergic rxns (immediate hypersensitivity reaction or severe anaphylaxis). First exposure--> production of IgE which binds to surface of mast cells and 2nd exposure binds antigen to IgE triggering release of histamine, heparin, ECF-A and leukotrienes
Function of Histamine
(1) causes contraction of smooth muscle (broncoconstricts)
(2) dilates and increases permeability of post capillary venules
Function of Leukotrienes
(1) slow contraction in smooth muscle
ECF-A (eosinophil chemotactic factor of anaphylaxis)
(1) attract eosinophils
(1) a glycosaminoglycan (GAG), interfers with blood clotting. The mucosal mast cells contain chondroitin suplphate instead of heparin
B-glucuronidase and aryl sulfatase
(1) enzymes that breakdown GAGs
T and B lymphocytes: (1) histologic characteristics
(1) 7-8 um. Cell and nucleus are round. chromatin is highly condensed and stains blue black. Thin crescent of basophilic cytoplasm is sometimes visible
T/B lymphocytes: (2) lineage and (3) life span
(2) ?? (3) B lymphocytes is days to weeks and T cells is months to years.
T/B lymphocytes: (4) Function
(1) T cell--cell mediated immunity (2) B cell--humoral immunity (more later in the block)

Both are monomorphonucelar luekocytes (unsegmented nucleus) + agranulocytes (doesn't produce specific granules) but cytoplasmic azurophilic granules may be visible
Plasma cell: (1) histiologic charcteristics
(1) Large 15-20 um + tear drop shape
(2) stains basophilc due to high ER content
(3) nucleus is eccentrically placed and may have condensed chromatin in a "clock face" staining pattern
(4) Nuclear hoff, a pale staining region near the nucleus, where golgi and centrioles are located
plasma cell (2): lineage (3) life span
(2) ??
(3) 10-20 days
Plasma cell (4) function
(1) effector cells of the activated B lymphocytes (2) commin in CT near epithelia and during chronic inflammation (3) in normal situations, NEVER IN BLOOD STREAM (4) synthesized antiboides, immunoglobulins that bind specifically to antigens that provoked their production
Eosinophils (1) histologic characteristics
(1) 12-14 um (2) nucleus: almost always bi-lobed with lobes of equal size (3) cytoplasm ctonains large,red specific (secondary) granules that contain b-glucuronidase, aryl sulfatase, acid phosphatase, and histaminase. Granule contains a crystalline core compsed of major basic protein (MBP)
Eosinophils (2) + (3)
(2) polymorphonuclear leukocyte (lobated nucleus) + granulocyte (specific granules (3) circulates in the bloods for a few horus before migrating into CT where they survive for a few days. During inflammation, many eosinophils enter the CT compartment. Eosinophilia occurs when there is a predominance in an inflammatory infiltrate
Eosinophils (4) Function
(1) during allergic reponses, ECF-A relased by mast cells attracts eosinophils into the CT copmartment where their enzymes inactivate histamine (aryl sulfatase, acid phosphatase, beta-glucorindase, and histaminase)
(2) eosinophils actively engulf antigen-antibody complexes formed during allergic reponses. (3) MBP kills parasitic worms
Neutrophil: (1) histologic characteristics
(1) round 12-15 um in diameter
(2) segmented nucleus 2-5 lobes (3) cytoplasm contains many specific granules tha tstain a pale blue-grey and azurophilic granules that stain purple-red
Neutrophil (2) lineage (3) life span
(2) polymorphonuclear leukocytes (lobated nucleus) + granulocyte (specific granules). Few neutorhpils are found in normal CT and life span is few days. But they rapidly gather in great numbers at site of bacterial infecitons where they phagocytize and digest pathogens.
Neutrophil (4): Function
(1) hallmark of acute inflammation
(2) specific granules contain alkaline phosphatse, collagenase, and lysozme. (3) Azurophilic grnaules contain peroxidase, acid phosphatase, and glucuronidase. (4) chemotactic factors are relased druign acute inflammation cause changes in capillary endothelium (allowing passage to migrate thru CT). (5) then ingest bacteria using enzymes from specific + azurophilic. (6) exudate (pus) formation
Fibroblasts (1)
(1) quiescent fibroblast (fibrocyte) is a fusiform with an oval or elongated heterochrmoatic nucleus. cytoplasm stains acidophilic (2) activated fibroblasts are large, basophilic, and stellate in shape. nucleus is large, ovoid, and lightly stained (eucrhomatic)
fibroblasts (2) + (3)
(1) ? principle structural cell of CT but largely quiescent in mature CT. Durin gchronic inflammation or repair, fibroblasts activate and synteshize extracellular fibers + matrix (3)?
Fibroblasts (4)
(1) in normal CT, synthesize collagen, elastin, and proteoglycans of the ground substance of CT but are sessile (2) tissue injury-- migrate to the site of injury to repair the damage where they proliferate and actively synthesize fibrous and amorphous components of CT needed for repair of the injury
Proliferate during repair and injury. Participate in angiogenesis
NK cell
specialized lymphocytes that lack receptors that typify B or T lymphocytes. Attack viru-infected cells and cancer cells without prior stimualtion so they participate in innate immunity
(1) disk shaped fragments of megakaryocytes that circulate in the blood stream (2) granules contains substances that promote blood clotting (3) patrol vascular system to detect any damage to the vascular lining (4) Breaks in endotehlium cause platelet adheres to exposed collage fibers + initiation of blood clot formation by aggregation