The lymphatic system provides structural and functional support to the immune system against pathogens.
The lymphoid organs, lymph, and lymphatic vessels …
Lymphatic vessels, or lymphatics, transport lymph from peripheral tissues to the venous system.
The journey of lymph begins in the thin-walled lymphatic …
The thymus and red bone marrow are the two primary lymphoid organs that are sites for lymphocyte production and maturation.
Red bone marrow is primarily …
Lymph nodes are small, bean-shaped structures that cluster along the lymphatic vessels. They are majorly located in the inguinal, axillary, and cervical …
The mesoderm cells of the developing veins form the precursor lymphatic vessels and nodes called lymph sacs.
The paired jugular lymph sacs are the first …
Present from birth, innate immunity is the body's first line of defense against a wide range of harmful pathogens.
It provides immediate, non-specific …
Antimicrobial proteins, such as interferons, the complement system, iron-binding proteins, and antimicrobial peptides, enhance the immune response by …
Immune surveillance involves monitoring peripheral tissues to detect pathogens and infected or cancerous body cells.
Natural killer, or NK cells, which …
The adaptive immune system provides a specialized defense using T and B lymphocytes with specific features to combat infections effectively.
These cells …
Antigen-presenting cells, also known as APCs, process foreign antigens, such as fragments from pathogens, for recognition by T cells.
When an APC engulfs …
Naive T cells express membrane proteins called the cluster of differentiation, or CD markers with the T cell receptor or TCR.
There are two major T cell …
Activated T cells with CD4 markers give rise to the effector helper and regulatory T cells, while the effector cytotoxic T cells arise from T cells with …
Naive B cells become sensitized when they encounter their corresponding antigen, which binds to the B cell receptor, or BCR, on the cell surface.
After …
Antibodies, also known as immunoglobulins, are soluble proteins produced by effector B cells called plasma cells in response to foreign substances like …
Antibodies recognize and bind antigens to form antigen-antibody complexes for pathogen elimination.
After binding to an antigen, the antibody neutralizes …
Immunological memory is the ability to react faster to the antigens that have previously activated the immune response.
This occurs due to long-lived …
Cell-mediated immunity in a fetus begins at the third month of growth, and active antibody-mediated immunity follows about one month later.
The first …
The immune defense against pathogenic bacteria involves phagocytes like macrophages from the innate system along with the T and B cells from the adaptive …
Upon viral infection, cells secrete interferons to protect uninfected cells and activate the patrolling NK cells to initiate a non-specific innate immune …
Immunodeficiency diseases occur due to exposure to immunosuppressive agents, poor development of lymphoid organs, or viral infections.
Prolonged use of …
In an autoimmune disorder, the body's immune system mistakenly attacks its own cells and tissues by activating self-reactive T and B cells.
There are …
Immunological memory, the hallmark of adaptive immunity, is orchestrated by T and B lymphocytes. In circulation and different organs, there are billions …
Fms-like tyrosine kinase 3 ligand (Flt3L) is a hematopoietic cytokine that promotes the survival and differentiation of dendritic cells (DCs). It has been …
