#6 - Phagocytes and Natural Killing Vibes

Phagocytes

a type of white blood cell that use phagocytosis to engulf bacteria

monocytes macrophages

2 types of phagocytes

Monocytes

agranulocytes, formed in the bone marrow; are immature type cells and are not phagocytic, but after several hours in the tissue, they mature into macrophages.

Macrophages

e capable of ingesting large quantities of cell debris and bacteria

The monocyte-macrophage cell

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reticuloendothelial system

monocyte-macrophage cell system is called

monocyte-macrophage cell system

a class of cells that occur in widely separated parts of the human body

Kupffer cells

so-called fuzzy coat

Neutrophils

The granules in the neutrophils are necessary for chemotaxis, chemoattractant, breaking down of pathogens, and bactericidal activity.

Tissue dendritic cells

are responsible for initiating all antigen-specific immune responses

Tissue dendritic cells

They are professional antigenpresenting cells that inform the fight against invasive pathogens while enforcing tolerance to self and harmless environmental antigens.

Tissue dendritic cells

They capture pathogens and receive signals from pathogens that influence the outcome of immune responses.

Tissue dendritic cells

Examples: lung mucosa, epithelial cells of the skin, and the linings of the nose and the gastrointestinal tract.

Mast cells

are bags of granules found throughout the loose connective tissue surrounding the blood vessels.

mast cell degranulation

They burst open and release their intracellular contents (histamine) during tissue injury, exposure to toxins, and the presence of pathogens.

mast cell degranulation

contributes to vasodilation, increased capillary permeability, and the drawing of WBCs and platelets in the area of injury or infection.

Natural Killer (NK) cells

are effector lymphocytes of the innate immune system that control several types of tumors and microbial infections by limiting their spread and subsequent tissue damage.

cell lysis and induce aptosis

what does natural killer cells promote

induce apoptosis

direct cell attack against virus-infected or tumor (cancerous) cells.

cell lysis

e.g. perforin and granzymes

perforin

enters the foreign cell’s plasma membrane

Granzymes

(protein-digesting enzymes)

Granzymes

enter and kill the foreign cell (induced apoptosis)

Macrophages

remove apoptotic and aged cells.