Immunology
Organs of the Immune System 22/10/2014
Presented By:
Mohammad Nouman (7202) Hamza mehmood (7247) Shafia Shahid (7253) Naveed Akber (7254) Narjis Khatoon (7257) Asiya Ejaz (7266) Ayesha Nasir (7270)
Scheme of presentation:
Organ: Student:
Introduction to organs & LT: Narjis Khatoon
Thymus: Ayesha Nasir
Bone Marrow: Shafia Shahid
Lymph Nodes: Naveed Akbar
Spleen: Asiya Ejaz
Tonsils: Hamza Mehmood
Appendix & peyer’s Patches: M. Noumaan
Lymphoid System
Primary lymphoid organs Bone marrow
Thymus
Secondary lymphoid organs Organized Lymph nodes
Spleen
Tonsils
Less organized
Lymphatic System
Network of vessels
Collects fluid from tissues
Major cell is lymphocyte
Unidirectional
Often first place where antigens are detected
Fig: Lymphatic system
.
Thymus
Structure
Gross
Bi-lobed
Lies above heart
Microscopic
Capsular
Lobules with outer cortex and inner medulla
Fig : Internal structure of Thymus
Thymus
Function
Takes in immature T cells and puts out mature (immunocompetent) T cells
Increased diversity of T cells
T cell selection
Thymus
T cell selection
Based on MHC/Ag complex recognition
Recognize MHC/Non self AG complexes
Recognize MHC/Self Ag complexes
Do not recognize MHC/Ag complexes
Athymic condition
Natural
Other
Bone marrow
Structure
Microscopic
Less well defined than thymus
Role of stromal cells
Function
Hematopoiesis
B cell maturation
B cell selection
Puts out mature, naive B cells
Fig: Structure of Bone Marrow
.
Lymph Nodes
Structure
Gross
Bean-shaped structures
Drains major segments of lymphatic system
Lymph Nodes
Structure
Microscopic
Major cell types
Lymphocytes
Macrophages
Dendritic cells
Cortex/paracortex/medulla
Follicles
Primary
Secondary
Fig: Microscopic structure of Lymph node
Lymph Nodes
Function
1st line of response to antigens
Secondary follicle (Germinal center) is site of B cell proliferation, mutation, differentiation
Specificity is high
Lympadenopathy
Lymphodoema
Spleen
Structure
Gross Ovoid organ in upper left quadrant of abdomen
Microscopic Compartmentalized
Red pulp
White pulp
Periarticualr lymphoid sheath Site of Ag presentation
Major cell types Lymphocytes
Macrophages
Dendritic cells
RBCs
Spleen
Function
Filters out older blood cells
Responds to Ag in circulatory system
Produces activated B cells
Production of blood cells
Reservior function
Splenagamy
Splenotomy
Tonsils
Collection of lymphoid tissue facing into
the aerodigestive track
1st line of defence against indested or inhaled foreign pathogens
Germinal centers appear in response to Ag
Produce T lymphocyte in a different way from spleen’s
Protective role in URI (Tonsillitis)
Fig: Tonsil’s Location
Appendix and Peyer’s Patches
Associated with large intestines and illium
Responds to Ag
Role in GI immune response
MALT (Mucosal associated lymphoid
tissue)
GALT (gut associated lymphoid tissue)
BALT (bronchial assiciated lymphoid
tissue)
NALT (nose associated lymphoid tissue)
VALT (vulvoveginal lymphoid tissue)
Fig: Lymph Tissues
References:
www.innerbody.com
www.sciencenetlink.com
www.livestrong.com
http://www.nature.com/cmi/journal/v9/n1/pdf/cmi201147a.pdf
http://www.bio.tamu.edu/courses/microbio/notes/Organs%20of%20the%20Immune%20System.pdf
And many more….
Top Related