Blood Cells and Immunity

Flashcards covering the formation, characteristics, and functions of blood cells and immune responses.

Platelets

Cytoplasmic fragments from megakaryocytes in bone marrow, important for hemostasis, wound repair, and inflammation.

Leukocytes

White blood cells formed in red bone marrow (leukopoiesis), classified as granulocytes or agranulocytes, provide defense against foreign invaders.

Granulocytes

White blood cells with prominent granules and a lobed nucleus, formed in red bone marrow through granulopoiesis.

Neutrophils

Abundant WBCs formed in red bone marrow, first responders to infection, perform phagocytosis, and critical in fighting bacterial infections and initiating inflammation.

Eosinophils

Granulocytes formed in red bone marrow, defend against parasitic infections and intracellular bacteria, degrade inflammatory mediators, and perform phagocytosis.

Basophils

Least numerous granulocytes, formed in red bone marrow, involved in allergic and inflammatory reactions, release histamine and heparin.

Monocytes

Largest white blood cells formed in red bone marrow, participate in inflammatory responses, become macrophages in tissues for long-term phagocytosis.

Lymphocytes

Agranulocytes formed from lymphoid stem cells in red bone marrow, include B cells, T cells, and Natural Killer cells.

B cells

Lymphocytes responsible for humoral immunity, defending against bacteria and toxins.

T cells

Lymphocytes providing cell-mediated immunity and help activate B cells that produce antibodies.

Natural Killer cells

Lymphocytes part of innate immunity, identify and kill virus-infected cells, stressed cells, and tumor cells without previous exposure.

Memory cells

B and T cells that 'remember' a specific pathogen and respond faster and more strongly on second exposure.