Lymphatic System Overview

Lymphatic System Overview

• The lymphatic system is a drainage system that removes excess fluids from body tissues and returns them to the bloodstream.
• It is a subsidiary system of both the circulatory and immune systems.

Function of the Lymphatic System

• The primary purpose of the circulatory system is to deliver oxygen and nutrients to body tissues and remove waste products.
• This exchange occurs in the smallest blood vessels called capillaries.
• However, not all of the fluid is reabsorbed into the bloodstream, leaving around 15% behind, which can cause swelling if accumulated.

Structure of the Lymphatic System

• The lymphatic system is a one-way network of vessels with open ends.
• It begins with lymphatic capillaries, which are composed of overlapping endothelial cells that act as a one-way valve.
• When fluid accumulates in tissues, the pressure increases, pushing the endothelial cells inward, and opening up gaps between the cells, allowing fluid to flow in.

Lymphatic Capillaries

• The gaps in lymphatic capillaries are large enough to allow bacteria, immune cells, and other large molecules to enter.
• This makes the lymphatic system a useful route for the delivery of large molecules into the bloodstream.

Lymphatic Vessels

• Once the fluid enters the lymphatic vessels, it is called lymph.
• The flow of lymph is enabled by the same forces that facilitate blood flow in veins.
• Lymph flows from smaller to larger vessels, eventually draining into the bloodstream through the subclavian veins.

Lymph Nodes

• Lymph nodes are small, bean-shaped structures scattered throughout the lymphatic network.
• They act as filters, cleaning the lymph before it reaches the bloodstream.
• Lymph nodes contain macrophages and immune cells that "engulf" pathogens, such as bacteria and viruses, and produce antibodies to combat infections.

Lymphoid Organs

• The lymphatic system includes lymphoid organs, which are primary sites of lymphocyte production, maturation, and selection.
• The primary lymphoid organs, including the bone marrow and thymus, are responsible for the production, maturation, and selection of lymphocytes.
• Lymphocytes then migrate to secondary lymphoid organs, including lymph nodes, spleen, and lymphoid follicles, where they encounter pathogens and become activated.

Lymphatic System Overview

• The lymphatic system is a drainage system that removes excess fluids from body tissues and returns them to the bloodstream.
• It is a subsidiary system of both the circulatory and immune systems.

Circulation and Lymphatic System

• The circulatory system delivers oxygen and nutrients to body tissues and removes waste products through capillaries.
• Around 15% of fluid is left behind, which can cause swelling if accumulated.

Structure and Function of Lymphatic System

• The lymphatic system is a one-way network of vessels with open ends, starting with lymphatic capillaries.
• Lymphatic capillaries have overlapping endothelial cells that act as a one-way valve, allowing fluid to flow in when tissue pressure increases.

Lymphatic Capillaries

• The gaps in lymphatic capillaries are large enough to allow bacteria, immune cells, and other large molecules to enter, making it a useful route for delivering large molecules into the bloodstream.

Lymphatic Vessels and Lymph Flow

• Fluid that enters the lymphatic vessels is called lymph, and its flow is enabled by the same forces that facilitate blood flow in veins.
• Lymph flows from smaller to larger vessels, eventually draining into the bloodstream through the subclavian veins.

Lymph Nodes

• Lymph nodes are small, bean-shaped structures that act as filters, cleaning the lymph before it reaches the bloodstream.
• They contain macrophages and immune cells that engulf pathogens, such as bacteria and viruses, and produce antibodies to combat infections.

Lymphoid Organs

• Lymphoid organs, including bone marrow and thymus, are primary sites of lymphocyte production, maturation, and selection.
• Lymphocytes then migrate to secondary lymphoid organs, including lymph nodes, spleen, and lymphoid follicles, where they encounter pathogens and become activated.

Lymphatic System Overview

• The lymphatic system is a drainage system that removes excess fluids from body tissues and returns them to the bloodstream.
• It is a subsidiary system of both the circulatory and immune systems.

Circulation and Lymphatic System

• The circulatory system delivers oxygen and nutrients to body tissues and removes waste products through capillaries.
• Around 15% of fluid is left behind, which can cause swelling if accumulated.

Structure and Function of Lymphatic System

• The lymphatic system is a one-way network of vessels with open ends, starting with lymphatic capillaries.
• Lymphatic capillaries have overlapping endothelial cells that act as a one-way valve, allowing fluid to flow in when tissue pressure increases.

Lymphatic Capillaries

• The gaps in lymphatic capillaries are large enough to allow bacteria, immune cells, and other large molecules to enter, making it a useful route for delivering large molecules into the bloodstream.

Lymphatic Vessels and Lymph Flow

• Fluid that enters the lymphatic vessels is called lymph, and its flow is enabled by the same forces that facilitate blood flow in veins.
• Lymph flows from smaller to larger vessels, eventually draining into the bloodstream through the subclavian veins.

Lymph Nodes

• Lymph nodes are small, bean-shaped structures that act as filters, cleaning the lymph before it reaches the bloodstream.
• They contain macrophages and immune cells that engulf pathogens, such as bacteria and viruses, and produce antibodies to combat infections.

Lymphoid Organs

• Lymphoid organs, including bone marrow and thymus, are primary sites of lymphocyte production, maturation, and selection.
• Lymphocytes then migrate to secondary lymphoid organs, including lymph nodes, spleen, and lymphoid follicles, where they encounter pathogens and become activated.