Feature-aligned N-BEATS with Sinkhorn divergence (ICLR '24)
Secondary lymphoid organ
1. VIVEKANANDHA COLLEGE OF ENGINEERING FOR WOMEN
BY :
P
.BHUVANESHWARI
3RD B.TECH/BIOTECHNOLOGY
SECONDARY LYMPHOID ORGANS
2. THYMUS GLAND
BONE MARROW
LYMPH NODES
SPLEEN
GALT,MALT,BALT
TONSILS
SALIVARY,TEAR
IMMUNE SYSTEM STRUCTURE
CENTRAL/PRIMARY
SECONDARY/PERIPHERAL
3. LYMPH NODES:
STRUCTURE OF LYMPH NODES
The lymph nodes are small, round or
ovoid bodies (2.6 cm in length)placed
along the course of lymphatic vessel.
Lymph nodes can be divided in to
three concentric regions:
Cortex
Paracortex
Medulla
The capsule is made of collagen and
has a sub capsular sinus.
The lymph flow into the sinus
carrying lymphocytes, Antigen
processing macrophages and
dendritic cells to the node Cortex,
Paracortex and medulla.
4. CORTEX:
The outermost layer, Cortex contains Lymphocytes (mostly B-cells),
Macrophages and Follicular dendritic cells arranged in Primary follicles.
The primary follicles enlarge in to Secondary follicles, each containing a
Germinal centre.
PARACORTEX:
The paracortex region of lymph nodes are populated with T-lymphocytes and
interdigitating dendritic cells.
In the paracortex also contain specialised blood vessels (high endothelial venules)
through which many B and T cells enter the nodes.
5. MEDULLA:
The medulla is the innermost layer of lymph node where the
lymphocytes are arranged as medullary cords.
The medullary cords contain antibody secreting plasma cells, B-cells and
macrophages.
The function of medullary sinus is to drains the lymph in to the efferent
lymphatic vessels.
FUNCTIONS OF LYMPH NODES:
Lymph nodes act as a filter for lymph(filtering interstitial fluid collected)
Filtering this exudative fluid allows for exposure of T and B cells to a wide range of
antigen
The exposure takes place with the aid of antigen presenting cells and dendritic cell.
Play a important role in adaptive immunity.
6.
7.
8. SPLEEN:
The spleen is an organ located in the left side of the Abdominal cavity under the
diaphragm, the muscular partition between the abdomen and chest.
9. The spleen in healthy adult is approximately 7cm (2.8 in)to 14 cm(5.5) in length.
It usually weighs between 150g and 200 g.
The spleen is surrounded by a capsule that extends a number of projections called
Trabeculae which it forms a compartmentalized structure.
The compartments are of two types.
Red pulp
White pulp which are separated by marginal zone
RED PULP:{Macrophages, numerous RBCs and few Lymphocytes}
Site where old and defective red blood cells are destroyed and removed.
WHITE PULP:{T-Lymphocytes}
The splenic white pulp surrounds the branches of the splenic artery forming a
Periarteriolar lymphoid sheath(PALS) populated mainly by T-lymphocytes.
13. MALT:
The mucous membranes lining the digestive, respiratory and urogenital systems
have a combined surface area of about 400m2 and are the major sites of entry for
most pathogens.
These vulnerable membrane surfaces are defended by a group of organized
lymphoid tissues mentioned collectively as Mucosal-associated lymphoid tissue
(MALT).
MALT
GALT BALT
14. Tonsils, Appendix and Peyer’s patches are the representative of lymphoid
tissue found in and around the mucosal epithelia.
TONSILS:
The Tonsils play a major role in
protecting the body against Respiratory
and Gastrointestinal Infection.
Each tonsil consists of a network of
crypts (pits) that store cells used to fight
infections.
The tonsils contains B and T cells that
fight against infections.
Tonsils produce antibodies against Polio,
Streptococcal pneumonia, Influenza and
numerous infection.
15. APPENDIX:
Appendix is a blind ended tube connected to the cecum.
The human appendix average 9 cm in length but can range from 2 to 20 cm. The
diameter of the appendix is usually between 7 and 8 cm.
16.
17. PEYER’S PATCHES:
Peyer’s patches are small masses of lymphatic tissue present throughout the ileum of
the small intestine.
It is roughly egg shaped lymphatic tissue nodules that are similar to lymph nodes in
structure except that they are not surrounded by a connective tissue capsule.
Important part of the immune system by monitoring intestinal bacteria population and
preventing the growth of pathogenic bacteria in the intestines.
Peyer’s patches also playing an important role in trapping antigens from pathogens
and destroying them.
18. Antigen transported across mucous membrane by M cells
Activate B cells in follicle
Differentiate in to plasma cells
Secrete Ig A class of antibodies
Transported across epithelial cells
Secretary Ig A in to lumen
Interact with antigen