Macrophages

-Alveolar macrophages in the lung

-Histiocytes in connective tissues

-Kupffer cells in the liver

-Mesangial cells in the kidney

-Microglial cells in the brain

- Osteoclasts in bone

Functions of Macrophages

- Phagocytosis

- Antimicrobial and cytotoxic activities

- Antigen processing and presentation

- Secretion of factors

Granulocytic Cells(granulocytes)

- Neutrophils

- Eosinophils

- Basophils

Dendritic Cells

- Langerhans cells in the epidermis (skin) and mucous membranes

- Interstitial dendritic cells in organs

- Interdigitating dendritic cells in secondary lymphoid tissue

- Circulating dendritic cells in the blood

- Veiled cells in the lymph

Development of Dendritic Cells

Organs of the Immune System

Primary (central) lymphoid organs- Provide appropriate microenvironments for the development and maturation of lymphocytes.

-thymus, bone marrow

Secondary (peripheral) lymphoid organs- Trap antigen from tissues or vascular spaces and are sites where mature lymphocytes can interact effectively with that antigen.

- lymph nodes, spleen, mucosal-associated lymphoid tissues (MALT), e.g., gut-associated lymphoid tissue (GALT).

Tertiary lymphoid tissue - Cutaneous-associated lymphoid tissues

Lymphatic System (淋巴系統 )

- Once mature lymphocytes have been generated in the primary lymphoid organs, they circulate in the blood and lymphatic system, a network of vessels that collect fluid that has escaped into the tissues from capillaries of the circulatory system and ultimately return it to the blood.

Lymphatic Vessels

The Human Lymphoid Systemsecondary

primary

The thymus

stromal cells:

m

aturation

A Lymph Node (1)

A Lymph Node (2)

The Spleen

The Spleen (1)

(血管神經出入口 )

The Spleen (2)

Mucosal-Associated lymphoid tissue (MALT)

TonsilsAppendixPeyer’s patches

- contain a large population of Ab-producing plasma cells

Tonsils

(上顎 ) (舌 )

(咽 )

Peyer’s Patch

contain intraepitheliallymphocytes IELs

B cells, plasma cell,activated TH cells & m

Structure of M Cells

Production of IgA Ab in the Gut

Cutaneous-associated Lymphoid Tissue