Anatomy: Blood Pt. 2 (Start with Leukocytes)

Leukocyte Function

Protect against infectious microorganisms and other pathogens

Spend only a few hours in the bloodstream before migrating to connective tissue

Form of a Leukocyte

Conspicuous nucleus

Retain their organelles for protein synthesis

Granules and Nonspecific granules (lysosomes)

Granuolocytes: containin enzymes and chemicals that protect against pathogens

Types of Leukocytes (Granulocytes)

Neutrophils: polymorphonuclear leukocytes

• barely visible granules in cytoplasm, 3-5 lobed nucleus

Eosinophils: Large rosy/orange granules, bilobed nucleus

Basophils: Large abundant violet granules, S shaped nucleus

Types of Leukocytes (Agranulocytes)

Lymphocytes: Variable amounts of bluish cytoplasm, ovoid dark violet nucleus

Monocytes: Usually largest WBC, ovoid/kidney shaped nucleus

Neutrophils

Aggressively antibacterial

Most common

contain neutrophilia: rise in number in response to bacterial infection

Eosinophils

Defend against parasitic infections, collagen diseases, allergies, and spleen and CNS diseases

Release enzymes to destroy large parasites

Completes Phagocytosis of antigen-antibody complexes

4th most common

Basophils

Increased numbers in chicken pox, sinusitis, diabetes

secrete histamine: speeds flow of blood to an injured area

secret heparine: promotes the mobility of other WBCs in the area

5th most common leukocyte

Lymphocytes

Increased numbers in diverse infections and immune responses

Destroy foreign and virally infected cells

Present antigens to activate other immune cells

Coordinate actions of other immune cells

Secrets antibodies and provide immune memory

Monocytes

Increased numbers in viral infections and inflammation

leave bloodstream and transform into macrophages

• phagocytize pathogens and debris

• present antigens to activate other immune cells (antigen presenting cells)