Lymphatic anatomy
What are the smallest lymphatic vessels called?
Lymphatic capillaries
What percentage of tissue fluid is returned to the blood as lymph?
15%
Which type of lymphocyte is involved in humoral immunity?
B lymphocytes.
What is the smallest lymphoid organ located in the throat area?
Tonsils.
How does lymph enter and exit lymph nodes?
It enters via afferent lymphatic vessels and exits via efferent lymphatic vessels.
What are the two main lymphatic ducts and their primary drainage areas?
Right lymphatic duct (right upper quadrant) and left lymphatic duct (rest of the body).
How does the lymphatic system contribute to lipid absorption?
By delivering fat from lacteals in the jejunum villi into the blood.
Where do T lymphocytes mature?
Where is the spleen located, and what is its primary function?
In the left hypochondriac region; it filters blood, phagocytoses old erythrocytes, and stores platelets and iron.
Why is lymph flow slower compared to blood flow?
Lymph flow is slower due to the lack of a pump and low pressure in lymphatic vessels.
What is the primary function of lymphatic trunks?
To drain major regions of the body.
What is the role of lymph nodes in the immune system?
To filter lymph, inspect it for foreign antigens and abnormal cells, and activate immune responses.
What are macrophages and their function in the lymphatic system?
Macrophages are large phagocytic cells that engulf and digest pathogens and debris.
What are Peyer’s patches, and where are they located?
Clusters of lymphatic nodules located in the ileum and appendix.
What methods help in the transport of lymph?
Contracting skeletal muscles, pulsations of nearby arteries, smooth muscle contractions, pressure changes in the thorax, and rapidly flowing blood in subclavian veins.
Name the six lymphatic trunks.
Paired lumbar, bronchomediastinal, subclavian, intercostal, jugular trunks, and single intestinal trunk.
How is lymph involved in fluid recovery?
Lymph returns leaked plasma proteins and tissue fluid back to the blood.
Name the cell type that forms reticular connective tissue in lymphoid organs.
Reticular cells.
What type of tissue composes lymphoid organs?
Reticular connective tissue.
What role do lymph nodes play in filtering lymph?
They filter lymph to remove impurities and pathogens, activating an immune response.
Describe the convergence process of lymphatic vessels.
Lymphatic vessels converge and become larger as they move toward the heart.
Describe how the lymphatic system aids in defense and immunity.
By inspecting lymph for pathogens and abnormal cells and activating an immune response.
Which lymphocytes are primarily involved in cellular immunity?
T lymphocytes
Describe the primary functions of the tonsils.
To respond to inhaled or ingested foreign substances and trap foreign antigens.
Describe the role of one-way valves in lymphatic vessels.
They ensure the unidirectional flow of lymph towards the heart and prevent backflow.