Lymphatic System :Lymphatic System


Introduction :Introduction Components Lymph is the fluid Vessels – lymphatics Structures & organs Functions Return tissue fluid to the bloodstream Transport fats from the digestive tract to the bloodstream Surveillance & defense


The Lymphatic System :The Lymphatic System


Lymphatics :Lymphatics Originate as lymph capillaries Capillaries unite to form larger vessels Resemble veins in structure Connect to lymph nodes at various intervals Lymphatics ultimately deliver lymph into 2 main channels Right lymphatic duct Drains right side of head & neck, right arm, right thorax Empties into the right subclavian vein Thoracic duct Drains the rest of the body Empties into the left subclavian vein


Lymph Capillaries :Lymph Capillaries


Lymphatic Vessels :Lymphatic Vessels


Main Channels of Lymphatics :Main Channels of Lymphatics


Major Lymphatic Vessels of the Trunk :Major Lymphatic Vessels of the Trunk


Lymph Tissue :Lymph Tissue 3 types Diffuse lymphatic tissue No capsule present Found in connective tissue of almost all organs Lymphatic nodules No capsule present Oval-shaped masses Found singly or in clusters Lymphatic organs Capsule present Lymph nodes, spleen, thymus gland


Lymph Nodules :Lymph Nodules


Lymph Nodes :Lymph Nodes Oval structures located along lymphatics Enclosed by a fibrous capsule Cortex = outer portion Germinal centers produce lymphocytes Medulla = inner portion Medullary cords Lymph enters nodes through afferent lymphatics, flows through sinuses, exits through efferent lymhpatic


Lymph Node :Lymph Node


Tonsils :Tonsils Multiple groups of large lymphatic nodules Location – mucous membrane of the oral and pharyngeal cavities Palatine tonsils Posterior-lateral walls of the oropharynx Pharyngeal tonsil Posterior wall of nasopharynx Lingual tonsils Base of tongue


Tonsils :Tonsils


Spleen :Spleen Largest lymphatic organ Located between the stomach & diaphragm Structure is similar to a node Capsule present But no afferent vessels or sinuses Histology Red pulp contains all the components of circulating blood White pulp is similar to lymphatic nodules Functions Filters blood Stores blood


Spleen :Spleen


Thymus Gland :Thymus Gland Location – behind the sternum in the mediastinum The capsule divides it into 2 lobes Development Infant – conspicuous Puberty – maximum size Maturity – decreases in size Function Differentiation and maturation of T cells


Thymus Gland :Thymus Gland


Function of the Lymphatic System :Function of the Lymphatic System Defense against harmful organisms and chemicals 2 types of defense Nonspecific Specific Specific defense = immunity Humoral immunity involves B cells that become plasma cells which produce antibodies that bind with specific antigens. Cell-mediated immunity involves T cells that directly destroy foreign cells


Derivation and Distribution of Lymphocytes :Derivation and Distribution of Lymphocytes