TheLymphatic
System
** The lymphatic system is the system of vessels, cells, and organsthat carries excess fluids to the bloodstream and filters pathogens from the blood .
** is part of the circulatory system and a vital part of the immune system .
Lymphatic SystemComponents of Lymphatic System :-
A- Lymph Vessels . Lymphatic Capillaries .Lymph is the fluid .Lymphatic vessels .Lymph nodes .Lymphatic ducts .
. Lymph is formed when high arterial pressure forces fluid out of the capillaries and into the tissue.
* The human circulatory system processes an average of 20 litres of blood per day through capillary filtration, which removes plasma while leaving the blood cells. Roughly 17 litres of the filtered plasma are reabsorbed directly into the blood vessels, while the remaining three litres remain in the interstitial fluid.
Lymph Fluid
Lymph Drainage Into Veins
Lymph Vessels
* The lymph vessels transport the lymph to the lymph nodes, which are soft, ovoid organs lying along the course of lymphatic vessels.
* They range in size from 2 - 25 mm. There can be from 400 - 700 nodes scattered throughout the human body.
* Half of them are located in the abdomen; many are in the cervical (neck) region. The main groups of nodes are found in the major articulations of the body, with the exception of the wrists.
LYMPH NODES
• HELP PROTECT THE BODY BY REMOVING FOREIGN MATERIAL (BACTERIA AND TUMOR CELLS)
• PROTECT THE BODY BY PRODUCING LYMPHOCYTES .
• LARGE CLUSTERS IN INGUINAL, AXILLARY, CERVICAL REGIONS
• OUTER CORTEX CONTAIN LYMPHOCYTES, INNER MEDULLA CONTAIN PHAGOCYTIC MACROPHAGES
Lymph Node
CortexThe outer cortex consists mainly of the B cells arranged as follicles, which may develop a germinal center when challenged with an antigen, and the deeper cortex mainly consisting of the T cells .________________________________________________Medullacontains large blood vessels, sinuses and
medullary cords that contain antibody-secreting plasma cells.The medullary cords are cords of lymphatic tissue, and include plasma cells, macrophages, and B cells.
Lymph nodes filter the lymph and also contain large numbers of white blood cells (a big part of the immune system), which remove foreign cells and debris from the lymph.
When you get certain infections, the lymph nodes swell with billions of white blood cells working to clear the foreign cells that are causing the infection.
The filtered lymph then flows back into the blood stream at certain points.
• Intestinal Trunk
• Lumbar Trunk
• Bronchmediastinal Trunk
• Subclavian Trunk
• Jugular Trunks
Lymphatic Trunks
• Thoracic duct:
• Right lymphatic duct
Major Lymphatic ducts
The lymphatic system has a slow rhythm, low velocity and low pressure
Lymphatic tissue is made up of a framework of reticular fibers which are produced by reticular cells and which support lymphocytes, macrophages, and related cells. Lymphatic tissue may be found either as scattered foci of cells, as dense nodules within connective tissue (especially in the gut as tonsils or Peyer's Patches), or as aggregations of lymphoid cells enclosed within a capsule such as the lymph nodes, spleen and thymus. Primary : Bone Marrow – Thymus gland .Secondary : Tonsils Lymph NodesSpleen
B- Lymphatic tissue
Derivation and Distribution of Lymphocytes
Location – behind the sternum in the mediastinum
The capsule divides it into 2 lobesDevelopment
Infant – conspicuousPuberty – maximum sizeMaturity – decreases in size
FunctionDifferentiation and maturation of T cells
Thymus Gland
Thymus Gland
Largest lymphatic organLocated between the stomach & diaphragmStructure is similar to a node
Spleen
SPLEEN- FILTERS BLOOD- DESTROY WORN- OUT RBC- STORE PLATELETS AND ACT AS BLOOD
RESERVOIR- HEMATOPOEISIS IN FETUS BUT ONLY
PRODUCE LYMPHOCYTES IN ADULTS
Multiple groups of large lymphatic nodulesLocation – mucous membrane of the oral and
pharyngeal cavitiesPalatine tonsils
Posterior-lateral walls of the oropharynxPharyngeal tonsil
Posterior wall of nasopharynxLingual tonsils
Base of tongue
Tonsils
Tonsils
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Lymphocyte cells are produced in the bone marrow. There are two major classes: T cells processed in the thymus, and B cells which mature outside of the thymus. T cells act as messengers and destroyers against pathogens. B cells secrete antibodies that match a specific invading antigen. A lymphocyte is a type of white blood cell which function is to find and eliminate bacteria, viruses, and other foreign materials.
Lymphocytes
THYMUS GLAND- LYMPHATIC MASS OVERLYING THE
HEART- PRODUCES THYMOSIN HORMONE
TONSILS- RING THE PHARYNX- TRAP AND REMOVE ANY BACTERIA
ENTERING THE THROAT - ( TONSILLITIS)
PEYER’S PATCHES - PREVENT BACTERIA FROM
PENETRATING THE INTESTINAL WALL
CELLS OF THE IMMUNE SYSTEM
1. LYMPHOCYTESB LYMPHOCYTES – PRODUCE
ANTIBODIES- DEVELOP IN BM
T LYMPHOCYTES – CELL MEDIATED IMMUNITY
- DEVELOP IN THYMUS2. MACROPHAGES
ARISE FROM MONOCYTESENGULF FOREIGN PARTICLESPRESENT FRAGMENTS OF ANTIGENS ON
THEIR SURFACE
INTERACT WITH LYMPHOCTES IN IMMUNE
RESPONSE