The Lymphatic System

These flashcards cover key concepts and vocabulary related to the lymphatic system as outlined in the lecture notes.

Lymphatic System

A network of vessels and organs that produce immune cells and help defend the body.

Fluid Recovery

The process by which excess water and proteins are reabsorbed back into the blood.

Immunity

The ability of the body to resist infections by foreign cells and chemicals.

Lymph

A clear, colorless fluid that contains white blood cells and is recovered from interstitial fluid.

Lymphatic Vessels

Vessels that transport lymph throughout the body.

Lymphatic Capillaries

Small lymphatic vessels that penetrate nearly every tissue and absorb excess interstitial fluid.

Chyle

Milky fluid consisting of lymph and emulsified fats, typically found after meals.

Lymphatic Trunks

Larger lymphatic vessels that drain major body regions.

Collecting Ducts

Ducts that collect lymph from lymphatic trunks and empty into veins.

Natural Killer Cells

A type of lymphocyte that attacks invading cells and non-self cells.

B Lymphocytes

Lymphocytes that mature in the bone marrow and secrete antibodies.

T Lymphocytes

Lymphocytes that mature in the thymus and play a crucial role in immune responses.

Macrophages

Phagocytic cells that consume pathogens and cellular debris.

Tonsils

Lymphatic organs that guard against inhaled and ingested pathogens.

Spleen

The body's largest lymphatic organ, involved in blood monitoring and recycling of blood cells.

What is the primary function of the lymphatic system?

To maintain fluid balance, provide immune defense, and absorb dietary lipids.

What are the main components of the lymphatic system?

A network of vessels, tissues, and organs that produce immune cells.

What is lymph?

The fluid recovered from tissues, often clear and colorless, that may appear milky after a meal due to lipids.

What is the role of lymphatic vessels?

To transport lymph throughout the body.

What are lacteals?

Specialized lymphatic capillaries in the small intestine that absorb dietary lipids.

What is the function of lymphatic trunks?

To drain specific body portions, such as the lower limbs and intestines.

What are the two primary collecting ducts of the lymphatic system?

The Right Lymphatic Duct and the Thoracic Duct.

What does the Right Lymphatic Duct drain?

The right half of the thorax, head and neck, and right arm.

What does the Thoracic Duct drain?

The left upper thorax, head and neck, left upper limb, and below the diaphragm.

How does lymph flow through the lymphatic system?

Through smooth muscle contractions, respiratory pump, skeletal muscle pump, and valves preventing backflow.

What are Natural Killer Cells?

Immune cells that attack invaded and non-self cells.

What is the role of T Lymphocytes?

They mature in the thymus and are crucial for immune responses.

What do B Lymphocytes mature into?

Plasma cells that secrete antibodies.

What is the function of macrophages in the lymphatic system?

To engulf and digest cellular debris and pathogens, serving as antigen presenting cells.

What are lymph nodes and their primary functions?

Bean-shaped structures that cleanse lymph and activate T and B cells.

What are the three types of tonsils?

Lingual, palatine, and pharyngeal tonsils.

What is the spleen's function?

To monitor blood for pathogens, recycle old red blood cells, and aid in hemopoiesis in the fetus.

What is the significance of the thymus in the lymphatic system?

It is where T cells mature and secretes hormones to promote T cell development.

What is the appearance of lymph after a meal?

It may appear milky due to a high lipid content, known as chyle.

What are the characteristics of lymphatic capillaries?

They are closed at one end, lined with overlapping endothelial cells, and penetrate nearly every tissue except bone and the CNS.

What is the role of valves in lymphatic vessels?

To prevent backflow of lymph.

What are the major lymphatic trunks and their drainage functions?

Lumbar, intestinal, bronchiomediastinal, subclavian, and jugular trunks drain specific body regions.

What is the function of dendritic cells?

To alert the immune system of breaches in body surfaces and serve as antigen presenting cells.

What is the difference between lymphatic vessels and veins?

Lymphatic vessels lack a central pump and have lower pressure than veins.

What are the primary lymphatic organs?

Red bone marrow and thymus, where T and B lymphocytes become immunocompetent.

What is the structure of lymph nodes?

They have a hilum, fibrous capsule, and compartments divided by trabeculae.

What is the function of the red pulp in the spleen?

To contain sinuses filled with red blood cells and recycle old RBCs.