Lymphatic System Study Guide
Fluid Reabsorption
There is a small net loss of fluid because of the difference between hydrostatic pressure and osmotic pressure. The lymphatic system picks up fluid that leaks out of the capillaries and returns it to the circulation.
Lymphatic capillaries start in capillary beds
Lymphatic capillaries snake their way through capillary beds to pick up the excess fluid and return it back to the venous circulation. As fluid pressure increases, it forces open little flaps in the lymphatic capillaries, and the excess fluid enters the lymphatic system.
Lymphatic Vessels
Lymphatic capillaries lead to lymphatic vessels, which are somewhat similar to veins. Since the pressure is so low, they also need valves to help move the flow of lymph fluid or “lymph” back to the vessels.
Two major divisions of the Lymphatic System
Lymph from the upper right part of the body drains into the right lymphatic duct, which dumps its fluid into the right subclavian vein. Lymph from the rest of the body drains into the thoracic duct, which dumps its fluid into the left subclavian vein. Just as in veins, breathing helps move lymph up to the subclavian vein. The thoracic duct starts at the junction of several lymph vessels at a sac-like structure called the cisterna chyli. Because it collects lymph from the digestive organs, lymph from the thoracic duct is much higher in nutrients and fats.
Lymphoid Tissue
Lymphoid Tissue forms lymph nodules and lymph nodes. A reticular connective tissue bed is loaded with lymphocytes and macrophages, which filter toxins and attack disease organisms.
Lymph nodules and lymph nodes filter lymph
Arrangement of fibers into irregular trabeculae in lymph nodes forces the fluid to “percolate” through and encounter a large SA of lymphoid tissue. Germinal centers in the outer cortex contain many lymphocytes. Lymph nodes also consolidate vessels as there are fewer (and larger efferent vessels) leaving the lymph node than afferent vessels entering
There is a small net loss of fluid because of the difference between hydrostatic pressure and osmotic pressure. The lymphatic system picks up fluid that leaks out of the capillaries and returns it to the circulation.
Lymphatic capillaries start in capillary beds
Lymphatic capillaries snake their way through capillary beds to pick up the excess fluid and return it back to the venous circulation. As fluid pressure increases, it forces open little flaps in the lymphatic capillaries, and the excess fluid enters the lymphatic system.
Lymphatic Vessels
Lymphatic capillaries lead to lymphatic vessels, which are somewhat similar to veins. Since the pressure is so low, they also need valves to help move the flow of lymph fluid or “lymph” back to the vessels.
Two major divisions of the Lymphatic System
Lymph from the upper right part of the body drains into the right lymphatic duct, which dumps its fluid into the right subclavian vein. Lymph from the rest of the body drains into the thoracic duct, which dumps its fluid into the left subclavian vein. Just as in veins, breathing helps move lymph up to the subclavian vein. The thoracic duct starts at the junction of several lymph vessels at a sac-like structure called the cisterna chyli. Because it collects lymph from the digestive organs, lymph from the thoracic duct is much higher in nutrients and fats.
Lymphoid Tissue
Lymphoid Tissue forms lymph nodules and lymph nodes. A reticular connective tissue bed is loaded with lymphocytes and macrophages, which filter toxins and attack disease organisms.
Lymph nodules and lymph nodes filter lymph
Arrangement of fibers into irregular trabeculae in lymph nodes forces the fluid to “percolate” through and encounter a large SA of lymphoid tissue. Germinal centers in the outer cortex contain many lymphocytes. Lymph nodes also consolidate vessels as there are fewer (and larger efferent vessels) leaving the lymph node than afferent vessels entering