Immune system
General outline
Lymphatic organs,thymus,lymph node,
Lymphoid tissue
Lymphocyte
T,Th,Ts,Tc
B
K
NK
Macrophage
Cells
spleen,tonsil
Lymphoid tissue:
? consists of reticular tissue,macrophage,plasma
cell and lymphocyte
diffuse L.T.,no border,predominant T cell,
postcapillary venules (P.C.V.)
lymphoid nodules,clear border,predominant
B cells
Primary ~ Secondary ~Ag
lymphoid tissue
Lymphoid organs
? Central lymphoid organs
Thymus,the generation place of Tc
Bone marrow,the generation place of Bc
? Peripheral lymphoid organs
Contain lymph node,spleen,tonsil
The places to proceed immune reactions
Thymus
? Capsule ( C.T.) interlobular septa
? Cortex,
Endothelial reticular cell (ERC)
Lymphocyte,thymocyte
Macrophage,secrete IL-1
? Medulla:
ERC
Lc,few
Macrophage,secrete IL-1
Thymic corpuscles
Structure:
Thymus
The cortex of thymus
The medulla of thymus
Blood-thymus barrier:
endothelial cell of continuous capillary
very thick basement membrane
perivascular space with macrophage in it
basement membrane of ERC
ERC or their processes with desmosome
Prevents circular antigens from reaching the
thymic cortex where T cells are being formed
Consists of,
? the thymic ERC can secrete thymic
hormones (thymosin,thymolin,thymopoietin)
? induce the stem cell to differentiate into
T lymphocyte
Thymus function:
Lymph node
? scattered in the passages of lymph
? structure
capsule
parenchyma
Cortex
medulla
? function Perform immune reaction
Filtration of lymph
Structure:
? capsule,several afferent lymphatic vessels,
trabecula
? cortex
superficial cortex:
lymphoid nodule (B)
internodule zone
primary
secondary
paracortical zone,diffuse lymphoid tissue(T)
cortical lymphatic sinuses subcapsular sinus
peritrabecular sinus
? Medulla
? medullary cords:
contain many B cells,plasma cells,
macrophages
? medullary sinuses
many macrophages
Lymph node
The cortex of
lymph node
The medulla of lymph node
Recirculation of lymphocytes:
Lymphoid tissue Efferent lymphatic vessel
P.C.V,Blood circulation
Spleen
? located in the passages of blood
? structure
capsule
parenchyma
white pulp
red pulp
marginal zone? function
immune
filter blood to clear out the old red blood cells
hemopoiesis
blood storage
Structure:
? capsule,D.C.T,containing smooth muscle;
is covered by mesothelium
? white pulp
? periarterial lymphatic sheath,T predominant
? lymphatic nodules (splenic nodules),B
? marginal zone
lies between the white pulp and the red pulp
? red pulp
? splenic sinusoid
long rod endothelial cells ; gaps between
the adjacent cells; no basement
membrane; rounded by reticular fibers
? splenic cord
the main components are B,Mφ,etc; is
the principle place for filtration of blood
Spleen
The white pulp of spleen
The red pulp of spleen
Tonsil
? Mucosa
Epithelium
stratified squamous epithelium
form crypts
lymphocyte infiltration
Lamina propria lymphatic nodules
diffuse lymphatic tissue
? Capsule,C.T.
Tonsil
Mononuclear phagocyte system
Bone marrow
young monocyte
Blood
monocyte
Tissues or
organs
CT,macrophage
Liver,Kuffer cell
Lung,dust cell
Nerve tissue,microglia
Osseous tissue,osteoclast
Skin,Langerhans cell
Function of MPS:
? phagocytosis
? participate in immune reaction
? secrete bioactive substances