Chapter 25
The Lymphatic and Immune System
Introduction au système lymphatique et immunitaire
Immunity refers to the body's ability to resist infections and diseases. All cells and tissues that provide immunity collectively form the immune ...
Fonctions du système lymphatique et immunitaire
The lymphatic system provides structural and functional support to the immune system against pathogens.
The lymphoid organs, lymph, and lymphatic vessels ...
Vaisseaux lymphatiques et transport lymphatique
Lymphatic vessels, or lymphatics, transport lymph from peripheral tissues to the venous system.
The journey of lymph begins in the thin-walled lymphatic ...
Cellules et tissus lymphoïdes
Lymphoid cells and lymphoid tissues are the two major components of lymphoid organs.
Lymphoid cells consist of immune system cells such as B and T ...
Organes lymphoïdes primaires
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 ...
Organes lymphoïdes secondaires
Secondary lymphoid organs, such as the spleen, lymph nodes, and mucosa-associated lymphoid tissues or MALT, are the sites where lymphocytes first ...
Structure et fonction détaillées des ganglions lymphatiques
Lymph nodes are small, bean-shaped structures that cluster along the lymphatic vessels. They are majorly located in the inguinal, axillary, and cervical ...
Développement du système lymphatique
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 ...
Introduction à l’immunité innée et adaptative
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 ...
Barrières à membrane de surface
Surface barriers such as the skin and mucous membranes are the body's initial defense against pathogens, offering physical and chemical protection.
...
Cellules de la réponse immunitaire innée
The two essential cells involved in the innate immune responses are phagocytes and natural killer, or NK cells.
Phagocytes — microphages and ...
Protéines antimicrobiennes
Antimicrobial proteins, such as interferons, the complement system, iron-binding proteins, and antimicrobial peptides, enhance the immune response by ...
Système de complément
The complement system consists of about 20 plasma proteins, working together to fortify the body's defense against infections through opsonization, ...
Surveillance immunitaire par les cellules NK et les phagocytes
Immune surveillance involves monitoring peripheral tissues to detect pathogens and infected or cancerous body cells.
Natural killer, or NK cells, which ...
Réponse inflammatoire
An inflammatory response is a localized, non-specific immune reaction marked by redness, swelling, heat, pain, and occasional loss of function.
Any ...
Particularités de l’immunité adaptative
The adaptive immune system provides a specialized defense using T and B lymphocytes with specific features to combat infections effectively.
These cells ...
Cellules de la réponse immunitaire adaptative
In the bone marrow, the common lymphoid progenitor cells give rise to precursors for T and B lymphocytes.
Next, these precursors mature to gain ...
Antigènes impliqués dans l’immunité adaptative
Complete antigens, or simply antigens, are large, complex foreign molecules, mainly proteins, that initiate an immune response.
They possess two key ...
Diversité des récepteurs antigéniques
Antigen receptors are multiprotein complexes on the B and T cell membranes that recognize specific antigens.
A B cell antigen receptor, or BCR, is a ...
Cellules présentatrices d’antigènes
Antigen-presenting cells, also known as APCs, process foreign antigens, such as fragments from pathogens, for recognition by T cells.
When an APC engulfs ...
Voies de traitement des antigènes
The antigen-processing pathways break down antigens for presentation to lymphocytes.
The endogenous and exogenous pathways are the two main ...
Activation des lymphocytes T et sélection clonale
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 ...
Types et fonctions des lymphocytes T
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 ...
Réponse immunitaire médiée par les lymphocytes T cytotoxiques
Cytotoxic T cells target body cells infected by viruses, intracellular bacteria, or parasites. They also eliminate cancerous cells and foreign cells ...
Activation et différenciation des lymphocytes B
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 ...
Structure et classes d’anticorps
Antibodies, also known as immunoglobulins, are soluble proteins produced by effector B cells called plasma cells in response to foreign substances like ...
Actions des anticorps
Antibodies recognize and bind antigens to form antigen-antibody complexes for pathogen elimination.
After binding to an antigen, the antibody neutralizes ...
Mémoire immunologique
Immunological memory is the ability to react faster to the antigens that have previously activated the immune response.
This occurs due to long-lived ...
Immunité active ou passive
Active immunity refers to the process by which an individual's immune system is stimulated to produce a protective response to a pathogen, typically ...
Développement de l’immunocompétence
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 ...
Défense contre les agents pathogènes bactériens
The immune defense against pathogenic bacteria involves phagocytes like macrophages from the innate system along with the T and B cells from the adaptive ...
Réponse immunitaire contre les agents pathogènes viraux
Upon viral infection, cells secrete interferons to protect uninfected cells and activate the patrolling NK cells to initiate a non-specific innate immune ...
Maladies d’immunodéficience
Immunodeficiency diseases occur due to exposure to immunosuppressive agents, poor development of lymphoid organs, or viral infections.
Prolonged use of ...
Hypersensibilités
Hypersensitivity, or allergic reaction, occurs when the immune system overreacts to an allergen.
Hypersensitivity can be of four types.
Type I or ...
Maladies auto-immunes
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 ...
Transplantation de tissus
Tissue transplantation is a complex yet vital medical procedure that involves transferring cells, tissues, or organs from a donor to a recipient to ...
Immunothérapie tumorale
Cancer immunotherapy aids the body's immune system to identify and eliminate cancer cells, using vaccines, oncolytic viruses, activated patient T ...
Vaccins contre le cancer
Cancer vaccination can be preventive, protecting against oncogenic agents, or active, combating existing cancerous cells.
Like traditional vaccines, ...
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