the immune and lymphatic systems are two closely related organ systems that share several organs and...
TRANSCRIPT
The immune and lymphatic systems are two closely related organ systems that share several organs and physiological functions.
The immune system is our body’s defense against infectious pathogenic viruses, bacteria, and fungi as well as parasite and protists.
The immune system works to keep these harmful agents out of the body and attacks those that manage to enter
Introduction
Immune systemFunction of the immune system:
1. Has the ability to distinguish "self" from "non-self“
molecules (foreign substances).
2. Has the ability to neutralize or inactivate foreign molecules
(such as soluble molecules present in viruses, bacteria, and
parasites)
3. Destroy microorganisms or other cells (such as virus
infected cells, cells of transplanted organs, and cancer
cells).
Immune system
Autoimmune diseases :
The immune system of an individual reacts against its own
normal body tissues or molecules, causing autoimmune
diseases.
Immune system
The cells of the immune system:
1. Are distributed throughout the body in the blood, lymph,
epithelial and connective tissues.
2. Are arranged in small spherical nodules called lymphoid
nodules found in connective tissues and inside several
organs.
3. Are organized in larger lymphoid organs—the lymph nodes,
the spleen, the thymus, and the bone marrow.
4. Example to the immune cells- neutrophils, macrophages,
cytotoxic natural killer (NK). B .cell, T .cell, dendritic cell……
The lymphatic system is part of the circulatory system, comprising a network of lymphatic vessels that carry a clear fluid called lymph (from Latin lympha meaning water) directionally towards the heart . The lymph has a number of functions, including:Helps the body to get rid of toxins, waste and other unwanted materials Removal of interstitial fluid ( extracellular fluid of most tissue). It also acts as a highway, transporting white blood cells to and from the lymph nodes, and antigen-presenting cells to the lymph nodes.
LYMPHATIC SYSTEM
Lymphatic system
1. Lymphatic vessels:
which transport interstitial fluid (lymph) back to the blood
circulation
2. Lymphoid organs:
which house lymphocytes and other cells of the body's immune
defense system
Lymphoid organs
Lymphoid organs
Primary lymphoid organs
Secondary lymphoid organs
• Bone marrow• Thymus
• Lymph node• Spleen• Tonsils
Thymus
Thymus: primary lymphoid organ, composed of two identical
lobes and is located anatomically in front of the heart and
behind the sternum(is a long flat bony plate shaped like a capital
"T" located anteriorly to the heart in the center of the chest)
Thymus
Lobule :
Each lobule contain lymphoid tissue
Consist of :
Peripheral cortex
Central medullas
Interlobular septum
Thymic corpuscle
ThymusCortex: The cortical portion is mainly composed of lymphocytes, supported by a network of finely-branched epithelial reticular cells, which is continuous with a similar network in the medullary portion. The cortex is the location of the earliest events in thymocyte development Medulla: In the medullary portion, the reticulum is coarser than in the cortex, the lymphoid cells are relatively fewer in number. The medulla is the location of the latter events in thymocyte development.
Both cortex and medulla contain small lymphocyte (Called in this particular location as thymocytes.No lymphatic nodules are present in the thymus.
Thymus
Function of the thymus:
1.Production of T-Lymphocyte
2.Production of Thymosin
Function of Thymosin:
stimulates the development of T cells
Thymus
Development of thymus gland:
• This organ varies in size and development with the age of
the individual.
• After birth it continues to grow and attains its maximum
development around puberty.
• It decrease in size and its is gradually replaced by fat and
connective tissue
• In the old age very little thymatic tissue remains.